diff --git a/.editorconfig b/.editorconfig
index 4c91d0bf..02820dae 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -232,4 +232,8 @@ dotnet_diagnostic.CA1707.severity  = none  # Remove the underscores from type na
 dotnet_diagnostic.CA1720.severity  = none  # Identifier contains type name
 dotnet_diagnostic.CA1724.severity  = none  # Type names should not match namespaces
 dotnet_diagnostic.CA1859.severity  = none  # Use concrete types when possible for improved performance
+dotnet_diagnostic.CA1861.severity  = none  # Avoid constant arrays as arguments
+dotnet_diagnostic.CA2211.severity  = none  # Non-constant fields should not be visible
+dotnet_diagnostic.CA2241.severity  = error # Provide correct arguments to formatting methods/The format argument is not a valid string
+dotnet_diagnostic.IDE0040.severity = none  # Add accessibility modifiers
 dotnet_diagnostic.IDE1006.severity = none  # Naming rule violation
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 6f830b21..a6302259 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -77,9 +77,9 @@
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
         <PackageReference Include="NSubstitute" Version="5.1.0" />
         <PackageReference Include="System.ValueTuple" Version="4.5.0" />
-        <PackageReference Include="xunit.assert.source" Version="2.8.2-pre.19" />
-        <PackageReference Include="xunit.core" Version="2.8.2-pre.19" />
-        <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2-pre.7" />
+        <PackageReference Include="xunit.assert.source" Version="2.9.1-pre.5" />
+        <PackageReference Include="xunit.core" Version="2.9.1-pre.5" />
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
       </ItemGroup>
 
     </When>
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/ClassDataAttributeMustPointAtValidClassTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/ClassDataAttributeMustPointAtValidClassTests.cs
index 1756da84..3e92eb8d 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/ClassDataAttributeMustPointAtValidClassTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/ClassDataAttributeMustPointAtValidClassTests.cs
@@ -1,35 +1,36 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.ClassDataAttributeMustPointAtValidClass>;
 
 public class ClassDataAttributeMustPointAtValidClassTests
 {
-	static string TestMethodSource(string testMethodParams = "(int n)") => @$"
-#nullable enable
+	static string TestMethodSource(string testMethodParams = "(int n)") => string.Format(/* lang=c#-test */ """
+		#nullable enable
 
-using Xunit;
+		using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [ClassData(typeof(DataClass))]
-    public void TestMethod{testMethodParams} {{ }}
-}}";
+		public class TestClass {{
+		    [Theory]
+		    [ClassData(typeof(DataClass))]
+		    public void TestMethod{0} {{ }}
+		}}
+		""", testMethodParams);
 
 	public class SuccessCases
 	{
 		[Fact]
 		public async Task SuccessCaseV2()
 		{
-			var dataClassSource = @"
-using System.Collections;
-using System.Collections.Generic;
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections;
+				using System.Collections.Generic;
 
-class DataClass: IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}";
+				class DataClass: IEnumerable<object[]> {
+				    public IEnumerator<object[]> GetEnumerator() => null;
+				    IEnumerator IEnumerable.GetEnumerator() => null;
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV2(LanguageVersion.CSharp9, [TestMethodSource(), dataClassSource]);
 		}
@@ -37,105 +38,150 @@ class DataClass: IEnumerable<object[]> {
 		public static TheoryData<string, string> SuccessCasesV3Data = new()
 		{
 			// IEnumerable<ITheoryDataRow<int>> maps to int
-			{ "(int n)", @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-class DataClass: IEnumerable<TheoryDataRow<int>> {
-    public IEnumerator<TheoryDataRow<int>> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n)",
+				/* lang=c#-test */ """
+				using System.Collections;
+				using System.Collections.Generic;
+				using Xunit;
+
+				class DataClass: IEnumerable<TheoryDataRow<int>> {
+				    public IEnumerator<TheoryDataRow<int>> GetEnumerator() => null;
+				    IEnumerator IEnumerable.GetEnumerator() => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int>> maps to int
-			{ "(int n)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int>> with optional parameter
-			{ "(int n, int p = 0)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n, int p = 0)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int>> with params array (no values)
-			{ "(int n, params int[] a)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n, params int[] a)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int, string>> with params array (one value)
-			{ "(int n, params string[] a)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string>> {
-    public IAsyncEnumerator<TheoryDataRow<int, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n, params string[] a)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int, string, string>> with params array (multiple values)
-			{ "(int n, params string[] a)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string, string>> {
-    public IAsyncEnumerator<TheoryDataRow<int, string, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n, params string[] a)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string, string>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, string, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int, string[]>> with params array (array for params array)
-			{ "(int n, params string[] a)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string[]>> {
-    public IAsyncEnumerator<TheoryDataRow<int, string[]>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "(int n, params string[] a)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string[]>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, string[]>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int>> maps to generic T
-			{ "<T>(T t)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "<T>(T t)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<int>> maps to generic T?
-			{ "<T>(T? t)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "<T>(T? t)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<(int, int)>> maps unnamed tuple to named tuple
-			{ "((int x, int y) point)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<(int, int)>> {
-    public IAsyncEnumerator<TheoryDataRow<(int, int)>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "((int x, int y) point)",
+				/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<(int, int)>> {
+				    public IAsyncEnumerator<TheoryDataRow<(int, int)>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 			// IAsyncEnumerable<TheoryDataRow<(int, int)>> maps tuples with mismatched names
-			{ "((int x, int y) point)", @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<(int x1, int y1)>> {
-    public IAsyncEnumerator<TheoryDataRow<(int x1, int y1)>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}" },
+			{
+				/* lang=c#-test */ "((int x, int y) point)",
+				/* lang=c#-test */ """
+
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<(int x1, int y1)>> {
+				    public IAsyncEnumerator<TheoryDataRow<(int x1, int y1)>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				"""
+			},
 		};
 
 		[Theory]
@@ -150,72 +196,78 @@ public async Task SuccessCasesV3(
 
 	public class X1007_ClassDataAttributeMustPointAtValidClass
 	{
-		public static TheoryData<string> FailureCasesData = new()
-		{
+		public static TheoryData<string> FailureCasesData =
+		[
 			// Incorrect enumeration type (object instead of object[])
-			@"
-using System.Collections;
-using System.Collections.Generic;
-
-class DataClass: IEnumerable<object> {
-    public IEnumerator<object> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+
+			class DataClass: IEnumerable<object> {
+				public IEnumerator<object> GetEnumerator() => null;
+				IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
+
 			// Abstract class
-			@"
-using System.Collections;
-using System.Collections.Generic;
-
-abstract class DataClass: IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+
+			abstract class DataClass: IEnumerable<object[]> {
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
+
 			// Missing parameterless constructor
-			@"
-using System.Collections;
-using System.Collections.Generic;
-
-class DataClass: IEnumerable<object[]> {
-    public DataClass(string parameter) { }
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+
+			class DataClass: IEnumerable<object[]> {
+			    public DataClass(string parameter) { }
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
+
 			// Parameterless constructor is internal
-			@"
-using System.Collections;
-using System.Collections.Generic;
-
-class DataClass: IEnumerable<object[]> {
-    internal DataClass() { }
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+
+			class DataClass: IEnumerable<object[]> {
+			    internal DataClass() { }
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
+
 			// Parameterless constructor is private
-			@"
-using System.Collections;
-using System.Collections.Generic;
-
-class DataClass: IEnumerable<object[]> {
-    private DataClass() { }
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
-		};
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+
+			class DataClass: IEnumerable<object[]> {
+			    private DataClass() { }
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
+		];
 
 		[Theory]
 		[MemberData(nameof(FailureCasesData))]
 		public async Task FailureCases(string dataClassSource)
 		{
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1007")
-					.WithSpan(8, 6, 8, 34)
-					.WithArguments("DataClass", "IEnumerable<object[]>");
-			var expectedV3 =
-				Verify
-					.Diagnostic("xUnit1007")
-					.WithSpan(8, 6, 8, 34)
-					.WithArguments("DataClass", "IEnumerable<object[]>, IAsyncEnumerable<object[]>, IEnumerable<ITheoryDataRow>, or IAsyncEnumerable<ITheoryDataRow>");
+			var expectedV2 = Verify.Diagnostic("xUnit1007").WithSpan(7, 6, 7, 34).WithArguments("DataClass", "IEnumerable<object[]>");
+			var expectedV3 = Verify.Diagnostic("xUnit1007").WithSpan(7, 6, 7, 34).WithArguments("DataClass", "IEnumerable<object[]>, IAsyncEnumerable<object[]>, IEnumerable<ITheoryDataRow>, or IAsyncEnumerable<ITheoryDataRow>");
 
 			await Verify.VerifyAnalyzerV2(LanguageVersion.CSharp9, [TestMethodSource(), dataClassSource], expectedV2);
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource(), dataClassSource], expectedV3);
@@ -224,18 +276,15 @@ public async Task FailureCases(string dataClassSource)
 		[Fact]
 		public async Task IAsyncEnumerableNotSupportedInV2()
 		{
-			var dataClassSource = @"
-using System.Collections.Generic;
-using System.Threading;
-
-public class DataClass : IAsyncEnumerable<object[]> {
-    public IAsyncEnumerator<object[]> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1007")
-					.WithSpan(8, 6, 8, 34)
-					.WithArguments("DataClass", "IEnumerable<object[]>");
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+
+				public class DataClass : IAsyncEnumerable<object[]> {
+				    public IAsyncEnumerator<object[]> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1007").WithSpan(7, 6, 7, 34).WithArguments("DataClass", "IEnumerable<object[]>");
 
 			await Verify.VerifyAnalyzerV2(LanguageVersion.CSharp9, [TestMethodSource(), dataClassSource], expected);
 		}
@@ -246,23 +295,18 @@ public class X1037_TheoryDataTypeArgumentsMustMatchTestMethodParameters_TooFewTy
 		[Fact]
 		public async Task NotEnoughTypeParameters_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
-    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1037")
-					.WithSpan(8, 6, 8, 34)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, string f)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1037").WithSpan(7, 6, 7, 34).WithArguments("Xunit.TheoryDataRow");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, string f)"), dataClassSource], expected);
 		}
 	}
 
@@ -271,45 +315,35 @@ public class X1038_TheoryDataTypeArgumentsMustMatchTestMethodParameters_ExtraTyp
 		[Fact]
 		public async Task TooManyTypeParameters_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, double>> {
-    public IAsyncEnumerator<TheoryDataRow<int, double>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(8, 6, 8, 34)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, double>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, double>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1038").WithSpan(7, 6, 7, 34).WithArguments("Xunit.TheoryDataRow");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n)"), dataClassSource], expected);
 		}
 
 		[Fact]
 		public async Task ExtraDataPastParamsArray_Triggers()
 		{
-			var source = $@"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, double[], long>> {{
-    public IAsyncEnumerator<TheoryDataRow<int, double[], long>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(8, 6, 8, 34)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, params double[] d)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, double[], long>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, double[], long>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1038").WithSpan(7, 6, 7, 34).WithArguments("Xunit.TheoryDataRow");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, params double[] d)"), dataClassSource], expected);
 		}
 	}
 
@@ -318,45 +352,35 @@ public class X1039_TheoryDataTypeArgumentsMustMatchTestMethodParameters_Incompat
 		[Fact]
 		public async Task WithIncompatibleType_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string>> {
-    public IAsyncEnumerator<TheoryDataRow<int, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(9, 35, 9, 41)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("string", "DataClass", "d");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, double d)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, string>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1039").WithSpan(8, 35, 8, 41).WithArguments("string", "DataClass", "d");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, double d)"), dataClassSource], expected);
 		}
 
 		[Fact]
 		public async Task WithExtraValueNotCompatibleWithParamsArray_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string, int>> {
-    public IAsyncEnumerator<TheoryDataRow<int, string, int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(9, 42, 9, 50)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("int", "DataClass", "s");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, params string[] s)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<int, string, int>> {
+				    public IAsyncEnumerator<TheoryDataRow<int, string, int>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1039").WithSpan(8, 42, 8, 50).WithArguments("int", "DataClass", "s");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(int n, params string[] s)"), dataClassSource], expected);
 		}
 	}
 
@@ -365,97 +389,105 @@ public class X1040_TheoryDataTypeArgumentsMustMatchTestMethodParameters_Incompat
 		[Fact]
 		public async Task ValidTheoryDataRowMemberWithMismatchedNullability_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow<string?>> {
-    public IAsyncEnumerator<TheoryDataRow<string?>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1040")
-					.WithSpan(9, 28, 9, 34)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("string?", "DataClass", "s");
-
-			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(string s)"), source], expected);
+			var dataClassSource = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading;
+				using Xunit;
+
+				public class DataClass : IAsyncEnumerable<TheoryDataRow<string?>> {
+				    public IAsyncEnumerator<TheoryDataRow<string?>> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1040").WithSpan(8, 28, 8, 34).WithArguments("string?", "DataClass", "s");
+
+			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource("(string s)"), dataClassSource], expected);
 		}
 	}
 
 	public class X1050_ClassDataTheoryDataRowIsRecommendedForStronglyTypedAnalysis
 	{
-		public static TheoryData<string> FailureCasesData = new()
-		{
+		public static TheoryData<string> FailureCasesData =
+		[
 			// IEnumerable<object[]>
-			@"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
+			/* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class DataClass : IEnumerable<object[]> {
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
 
-public class DataClass : IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
 			// IAsyncEnumerable<object[]>
-			@"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
+			/* lang=c#-test */
+			"""
+			using System.Collections.Generic;
+			using System.Threading;
+			using Xunit;
+
+			public class DataClass : IAsyncEnumerable<object[]> {
+			    public IAsyncEnumerator<object[]> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+			}
+			""",
 
-public class DataClass : IAsyncEnumerable<object[]> {
-    public IAsyncEnumerator<object[]> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}",
 			// IEnumerable<ITheoryDataRow>
-			@"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class DataClass : IEnumerable<ITheoryDataRow> {
+			    public IEnumerator<ITheoryDataRow> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
 
-public class DataClass : IEnumerable<ITheoryDataRow> {
-    public IEnumerator<ITheoryDataRow> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
 			// IAsyncEnumerable<ITheoryDataRow>
-			@"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
+			/* lang=c#-test */
+			"""
+			using System.Collections.Generic;
+			using System.Threading;
+			using Xunit;
+
+			public class DataClass : IAsyncEnumerable<ITheoryDataRow> {
+			    public IAsyncEnumerator<ITheoryDataRow> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+			}
+			""",
 
-public class DataClass : IAsyncEnumerable<ITheoryDataRow> {
-    public IAsyncEnumerator<ITheoryDataRow> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}",
 			// IEnumerable<TheoryDataRow>
-			@"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
+			/* lang=c#-test */
+			"""
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class DataClass : IEnumerable<TheoryDataRow> {
+			    public IEnumerator<TheoryDataRow> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+			""",
 
-public class DataClass : IEnumerable<TheoryDataRow> {
-    public IEnumerator<TheoryDataRow> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}",
 			// IAsyncEnumerable<TheoryDataRow>
-			@"
-using System.Collections.Generic;
-using System.Threading;
-using Xunit;
-
-public class DataClass : IAsyncEnumerable<TheoryDataRow> {
-    public IAsyncEnumerator<TheoryDataRow> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
-}",
-		};
+			/* lang=c#-test */
+			"""
+			using System.Collections.Generic;
+			using System.Threading;
+			using Xunit;
+
+			public class DataClass : IAsyncEnumerable<TheoryDataRow> {
+			    public IAsyncEnumerator<TheoryDataRow> GetAsyncEnumerator(CancellationToken cancellationToken = default) => null;
+			}
+			""",
+		];
 
 		[Theory]
 		[MemberData(nameof(FailureCasesData))]
 		public async Task FailureCases(string dataClassSource)
 		{
-			var expected =
-				Verify
-					.Diagnostic("xUnit1050")
-					.WithSpan(8, 6, 8, 34);
+			var expected = Verify.Diagnostic("xUnit1050").WithSpan(7, 6, 7, 34);
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, [TestMethodSource(), dataClassSource], expected);
 		}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/CollectionDefinitionClassesMustBePublicTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/CollectionDefinitionClassesMustBePublicTests.cs
index 0db73515..550a2c9d 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/CollectionDefinitionClassesMustBePublicTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/CollectionDefinitionClassesMustBePublicTests.cs
@@ -5,11 +5,12 @@
 public class CollectionDefinitionClassesMustBePublicTests
 {
 	[Fact]
-	public async Task ForPublicClass_DoesNotFindError()
+	public async Task ForPublicClass_DoesNotTrigger()
 	{
-		var source = @"
-[Xunit.CollectionDefinition(""MyCollection"")]
-public class CollectionDefinitionClass { }";
+		var source = /* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			public class CollectionDefinitionClass { }
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -17,28 +18,26 @@ public class CollectionDefinitionClass { }";
 	[Theory]
 	[InlineData("")]
 	[InlineData("internal ")]
-	public async Task ForFriendOrInternalClass_FindsError(string classAccessModifier)
+	public async Task ForFriendOrInternalClass_Triggers(string classAccessModifier)
 	{
-		var source = $@"
-[Xunit.CollectionDefinition(""MyCollection"")]
-{classAccessModifier}class CollectionDefinitionClass {{ }}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(3, 7 + classAccessModifier.Length, 3, 32 + classAccessModifier.Length);
+		var source = string.Format(/* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			{0}class [|CollectionDefinitionClass|] {{ }}
+			""", classAccessModifier);
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[InlineData("")]
 	[InlineData("public ")]
-	public async Task ForPartialClassInSameFile_WhenClassIsPublic_DoesNotFindError(string otherPartAccessModifier)
+	public async Task ForPartialClassInSameFile_WhenClassIsPublic_DoesNotTrigger(string otherPartAccessModifier)
 	{
-		var source = $@"
-[Xunit.CollectionDefinition(""MyCollection"")]
-public partial class CollectionDefinitionClass {{ }}
-{otherPartAccessModifier}partial class CollectionDefinitionClass {{ }}";
+		var source = string.Format(/* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			public partial class CollectionDefinitionClass {{ }}
+			{0}partial class CollectionDefinitionClass {{ }}
+			""", otherPartAccessModifier);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -47,19 +46,16 @@ public partial class CollectionDefinitionClass {{ }}
 	[InlineData("", "")]
 	[InlineData("", "internal ")]
 	[InlineData("internal ", "internal ")]
-	public async Task ForPartialClassInSameFile_WhenClassIsNonPublic_FindsError(
+	public async Task ForPartialClassInSameFile_WhenClassIsNonPublic_Triggers(
 		string part1AccessModifier,
 		string part2AccessModifier)
 	{
-		var source = $@"
-[Xunit.CollectionDefinition(""MyCollection"")]
-{part1AccessModifier}partial class CollectionDefinitionClass {{ }}
-{part2AccessModifier}partial class CollectionDefinitionClass {{ }}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(3, 15 + part1AccessModifier.Length, 3, 40 + part1AccessModifier.Length)
-				.WithSpan(4, 15 + part2AccessModifier.Length, 4, 40 + part2AccessModifier.Length);
+		var source = string.Format(/* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			{0}partial class {{|#0:CollectionDefinitionClass|}} {{ }}
+			{1}partial class {{|#1:CollectionDefinitionClass|}} {{ }}
+			""", part1AccessModifier, part2AccessModifier);
+		var expected = Verify.Diagnostic().WithLocation(0).WithLocation(1);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/ConstructorsOnFactAttributeSubclassShouldBePublicTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/ConstructorsOnFactAttributeSubclassShouldBePublicTests.cs
index 378a95c0..76a67055 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/ConstructorsOnFactAttributeSubclassShouldBePublicTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/ConstructorsOnFactAttributeSubclassShouldBePublicTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.ConstructorsOnFactAttributeSubclassShouldBePublic>;
 
@@ -8,20 +7,21 @@ public class ConstructorsOnFactAttributeSubclassShouldBePublicTests
 	[Fact]
 	public async Task DefaultConstructor_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute { }
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute { }
 
-public class Tests {
-    [CustomFact]
-    public void TestCustomFact() { }
+			public class Tests {
+			    [CustomFact]
+			    public void TestCustomFact() { }
 
-    [Fact]
-    public void TestFact() { }
-}";
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -29,24 +29,25 @@ public void TestFact() { }
 	[Fact]
 	public async Task ParameterlessPublicConstructor_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute {
-    public CustomFactAttribute() {
-        this.Skip = ""xxx"";
-    }
-}
-
-public class Tests {
-    [CustomFact]
-    public void TestCustomFact() { }
-
-    [Fact]
-    public void TestFact() { }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute {
+			    public CustomFactAttribute() {
+			        this.Skip = "xxx";
+			    }
+			}
+
+			public class Tests {
+			    [CustomFact]
+			    public void TestCustomFact() { }
+
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -54,24 +55,25 @@ public void TestFact() { }
 	[Fact]
 	public async Task PublicConstructorWithParameters_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute {
-    public CustomFactAttribute(string skip) {
-        this.Skip = skip;
-    }
-}
-
-public class Tests {
-    [CustomFact(""blah"")]
-    public void TestCustomFact() { }
-
-    [Fact]
-    public void TestFact() { }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute {
+			    public CustomFactAttribute(string skip) {
+			        this.Skip = skip;
+			    }
+			}
+
+			public class Tests {
+			    [CustomFact("blah")]
+			    public void TestCustomFact() { }
+
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -79,28 +81,29 @@ public void TestFact() { }
 	[Fact]
 	public async Task PublicConstructorWithOtherConstructors_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute {
-    public CustomFactAttribute() {
-        this.Skip = ""xxx"";
-    }
-
-    internal CustomFactAttribute(string skip) {
-        this.Skip = skip;
-    }
-}
-
-public class Tests {
-    [CustomFact]
-    public void TestCustomFact() { }
-
-    [Fact]
-    public void TestFact() { }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute {
+			    public CustomFactAttribute() {
+			        this.Skip = "xxx";
+			    }
+
+			    internal CustomFactAttribute(string skip) {
+			        this.Skip = skip;
+			    }
+			}
+
+			public class Tests {
+			    [CustomFact]
+			    public void TestCustomFact() { }
+
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -108,28 +111,24 @@ public void TestFact() { }
 	[Fact]
 	public async Task InternalConstructor_Triggers()
 	{
-		var source = @"
-using System;
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute {
-    internal CustomFactAttribute(string skip, params int[] values) { }
-}
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute {
+			    internal CustomFactAttribute(string skip, params int[] values) { }
+			}
 
-public class Tests {
-    [CustomFact(""Skip"", 42)]
-    public void TestCustomFact() { }
+			public class Tests {
+			    [{|#0:CustomFact("Skip", 42)|}]
+			    public void TestCustomFact() { }
 
-    [Fact]
-    public void TestFact() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithSpan(11, 6, 11, 28)
-				.WithArguments("CustomFactAttribute.CustomFactAttribute(string, params int[])");
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("CustomFactAttribute.CustomFactAttribute(string, params int[])");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -137,30 +136,26 @@ public void TestFact() { }
 	[Fact]
 	public async Task ProtectedInternalConstructor_Triggers()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
-internal sealed class CustomFactAttribute : FactAttribute {
-    protected internal CustomFactAttribute() {
-        this.Skip = ""xxx"";
-    }
-}
-
-public class Tests {
-    [CustomFact]
-    public void TestCustomFact() { }
-
-    [Fact]
-    public void TestFact() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithSpan(13, 6, 13, 16)
-				.WithArguments("CustomFactAttribute.CustomFactAttribute()");
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+			internal sealed class CustomFactAttribute : FactAttribute {
+			    protected internal CustomFactAttribute() {
+			        this.Skip = "xxx";
+			    }
+			}
+
+			public class Tests {
+			    [{|#0:CustomFact|}]
+			    public void TestCustomFact() { }
+
+			    [Fact]
+			    public void TestFact() { }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("CustomFactAttribute.CustomFactAttribute()");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/DataAttributeShouldBeUsedOnATheoryTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/DataAttributeShouldBeUsedOnATheoryTests.cs
index 6d49dfbc..c314db68 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/DataAttributeShouldBeUsedOnATheoryTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/DataAttributeShouldBeUsedOnATheoryTests.cs
@@ -5,13 +5,14 @@
 public class DataAttributeShouldBeUsedOnATheoryTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForFactMethodWithNoDataAttributes()
+	public async Task FactMethodWithNoDataAttributes_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -20,14 +21,15 @@ public void TestMethod() { }
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task DoesNotFindErrorForFactMethodWithDataAttributes(string dataAttribute)
+	public async Task FactMethodWithDataAttributes_DoesNotTrigger(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.Fact]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.Fact]
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", dataAttribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -36,14 +38,15 @@ public void TestMethod() {{ }}
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task DoesNotFindErrorForTheoryMethodWithDataAttributes(string dataAttribute)
+	public async Task TheoryMethodWithDataAttributes_DoesNotTrigger(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.Theory]
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", dataAttribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -52,18 +55,15 @@ public void TestMethod() {{ }}
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task FindsErrorForMethodsWithDataAttributesButNotFactOrTheory(string dataAttribute)
+	public async Task MethodsWithDataAttributesButNotFactOrTheory_Triggers(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27);
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.{0}]
+			    public void [|TestMethod|]() {{ }}
+			}}
+			""", dataAttribute);
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseAsyncVoidForTestMethodsTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseAsyncVoidForTestMethodsTests.cs
index c117a595..a325a6f6 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseAsyncVoidForTestMethodsTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseAsyncVoidForTestMethodsTests.cs
@@ -7,14 +7,15 @@ public class DoNotUseAsyncVoidForTestMethodsTests
 	[Fact]
 	public async Task NonTestMethod_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading.Tasks;
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
 
-public class MyClass {
-    public async void MyMethod() {
-        await Task.Yield();
-    }
-}";
+			public class MyClass {
+			    public async void MyMethod() {
+			        await Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -22,13 +23,14 @@ public async void MyMethod() {
 	[Fact]
 	public async Task NonAsyncTestMethod_DoesNotTrigger()
 	{
-		var source = @"
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -36,16 +38,17 @@ public void TestMethod() { }
 	[Fact]
 	public async Task AsyncTaskMethod_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        await Task.Yield();
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async Task TestMethod() {
+			        await Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -53,43 +56,37 @@ public async Task TestMethod() {
 	[Fact]
 	public async Task AsyncValueTaskMethod_V3_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async ValueTask TestMethod() {
-        await Task.Yield();
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async ValueTask TestMethod() {
+			        await Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV3(source);
 	}
 
-
 	[Fact]
 	public async Task AsyncVoidMethod_Triggers()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void TestMethod() {
-        await Task.Yield();
-    }
-}";
-
-		var expectedV2 =
-			Verify
-				.Diagnostic("xUnit1048")
-				.WithSpan(7, 23, 7, 33);
-		var expectedV3 =
-			Verify
-				.Diagnostic("xUnit1049")
-				.WithSpan(7, 23, 7, 33);
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async void {|#0:TestMethod|}() {
+			        await Task.Yield();
+			    }
+			}
+			""";
+		var expectedV2 = Verify.Diagnostic("xUnit1048").WithLocation(0);
+		var expectedV3 = Verify.Diagnostic("xUnit1049").WithLocation(0);
 
 		await Verify.VerifyAnalyzerV2(source, expectedV2);
 		await Verify.VerifyAnalyzerV3(source, expectedV3);
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseBlockingTaskOperationsTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseBlockingTaskOperationsTests.cs
index decb6b9d..276128a6 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseBlockingTaskOperationsTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseBlockingTaskOperationsTests.cs
@@ -8,16 +8,17 @@ public class DoNotUseBlockingTaskOperationsTests
 	[Fact]
 	public async Task SuccessCase()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        await Task.Delay(1);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async Task TestMethod() {
+			        await Task.Delay(1);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -25,23 +26,24 @@ public async Task TestMethod() {
 	public class IValueTaskSource_NonGeneric
 	{
 		[Fact]
-		public async Task FailureCase_GetResult()
+		public async Task GetResult_Triggers()
 		{
-			var source = @"
-using System;
-using System.Threading.Tasks.Sources;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        default(IValueTaskSource).[|GetResult(0)|];
-        Action<IValueTaskSource> _ = vts => vts.GetResult(0);
-        void LocalFunction() {
-            default(IValueTaskSource).GetResult(0);
-        }
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Threading.Tasks.Sources;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        default(IValueTaskSource).[|GetResult(0)|];
+				        Action<IValueTaskSource> _ = vts => vts.GetResult(0);
+				        void LocalFunction() {
+				            default(IValueTaskSource).GetResult(0);
+				        }
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
@@ -50,23 +52,24 @@ void LocalFunction() {
 	public class IValueTaskSource_Generic
 	{
 		[Fact]
-		public async Task FailureCase_GetResult()
+		public async Task GetResult_Triggers()
 		{
-			var source = @"
-using System;
-using System.Threading.Tasks.Sources;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        default(IValueTaskSource<int>).[|GetResult(0)|];
-        Func<IValueTaskSource<int>, int> _ = vts => vts.GetResult(0);
-        void LocalFunction() {
-            default(IValueTaskSource<int>).GetResult(0);
-        }
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Threading.Tasks.Sources;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        default(IValueTaskSource<int>).[|GetResult(0)|];
+				        Func<IValueTaskSource<int>, int> _ = vts => vts.GetResult(0);
+				        void LocalFunction() {
+				            default(IValueTaskSource<int>).GetResult(0);
+				        }
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
@@ -77,129 +80,135 @@ public class Task_NonGeneric
 		public class Wait
 		{
 			[Fact]
-			public async Task FailureCase()
+			public async Task Wait_Triggers()
 			{
-				var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Task.Delay(1).[|Wait()|];
-        Action<Task> _ = t => t.Wait();
-        void LocalFunction() {
-            Task.Delay(1).Wait();
-        }
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System;
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        Task.Delay(1).[|Wait()|];
+					        Action<Task> _ = t => t.Wait();
+					        void LocalFunction() {
+					            Task.Delay(1).Wait();
+					        }
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 			}
 
 			[Fact]
-			public async Task FailureCase_BeforeWhenAll()
+			public async Task Wait_BeforeWhenAll_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task = Task.Delay(1);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task = Task.Delay(1);
 
-        task.[|Wait()|];
+					        task.[|Wait()|];
 
-        await Task.WhenAll(task);
-    }
-}";
+					        await Task.WhenAll(task);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task FailureCase_WhenAllForOtherTask()
+			public async Task Wait_ForUnawaitedTask_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(new[] { task1 });
+					        await Task.WhenAll(new[] { task1 });
 
-        task1.Wait();
-        task2.[|Wait()|];
-    }
-}";
+					        task1.Wait();
+					        task2.[|Wait()|];
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_InContinueWithLambda()
+			public async Task Wait_InLambda_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Task.CompletedTask.ContinueWith(x => x.Wait());
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        Task.CompletedTask.ContinueWith(x => x.Wait());
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAll()
+			public async Task Wait_AfterWhenAll_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(task1, task2);
+					        await Task.WhenAll(task1, task2);
 
-        task1.Wait();
-        task2.Wait();
-    }
-}";
+					        task1.Wait();
+					        task2.Wait();
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAny()
+			public async Task Wait_AfterWhenAny_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        var finishedTask = await Task.WhenAny(task1, task2);
+					        var finishedTask = await Task.WhenAny(task1, task2);
 
-        finishedTask.Wait();
-    }
-}";
+					        finishedTask.Wait();
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -210,23 +219,24 @@ public class WaitAny_WaitAll
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task FailureCase(string waitMethod)
+			public async Task WaitMethod_Triggers(string waitMethod)
 			{
-				var source = @$"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        Task.[|{waitMethod}(Task.Delay(1))|];
-        Action<Task> _ = t => Task.{waitMethod}(t);
-        void LocalFunction() {{
-            Task.{waitMethod}(Task.Delay(1));
-        }}
-    }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					using System;
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public void TestMethod() {{
+					        Task.[|{0}(Task.Delay(1))|];
+					        Action<Task> _ = t => Task.{0}(t);
+					        void LocalFunction() {{
+					            Task.{0}(Task.Delay(1));
+					        }}
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 			}
@@ -234,22 +244,23 @@ void LocalFunction() {{
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task FailureCase_BeforeWhenAll(string waitMethod)
+			public async Task WaitMethod_BeforeWhenAll_Triggers(string waitMethod)
 			{
-				var source = @$"
-using System.Threading.Tasks;
-using Xunit;
+				var source = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var task = Task.Delay(1);
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var task = Task.Delay(1);
 
-        Task.[|{waitMethod}(task)|];
+					        Task.[|{0}(task)|];
 
-        await Task.WhenAll(task);
-    }}
-}}";
+					        await Task.WhenAll(task);
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -257,25 +268,26 @@ public async Task TestMethod() {{
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task FailureCase_WhenAllForOtherTask(string waitMethod)
+			public async Task WaitMethod_ForUnawaitedTask_Triggers(string waitMethod)
 			{
-				var source = @$"
-using System.Threading.Tasks;
-using Xunit;
+				var source = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(new[] {{ task1 }});
+					        await Task.WhenAll(new[] {{ task1 }});
 
-        Task.{waitMethod}(task1);
-        Task.[|{waitMethod}(task2)|];
-        Task.[|{waitMethod}(task1, task2)|];
-    }}
-}}";
+					        Task.{0}(task1);
+					        Task.[|{0}(task2)|];
+					        Task.[|{0}(task1, task2)|];
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -283,18 +295,19 @@ public async Task TestMethod() {{
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task SuccessCase_InContinueWithLambda(string waitMethod)
+			public async Task WaitMethod_InLambda_DoesNotTrigger(string waitMethod)
 			{
-				var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        Task.CompletedTask.ContinueWith(x => Task.{waitMethod}(x));
-    }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public void TestMethod() {{
+					        Task.CompletedTask.ContinueWith(x => Task.{0}(x));
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -302,25 +315,26 @@ public void TestMethod() {{
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task SuccessCase_AfterWhenAll(string waitMethod)
+			public async Task WaitMethod_AfterWhenAll_DoesNotTrigger(string waitMethod)
 			{
-				var source = @$"
-using System.Threading.Tasks;
-using Xunit;
+				var source = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(task1, task2);
+					        await Task.WhenAll(task1, task2);
 
-        Task.{waitMethod}(task1);
-        Task.{waitMethod}(task2);
-        Task.{waitMethod}(task1, task2);
-    }}
-}}";
+					        Task.{0}(task1);
+					        Task.{0}(task2);
+					        Task.{0}(task1, task2);
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -328,23 +342,24 @@ public async Task TestMethod() {{
 			[Theory]
 			[InlineData("WaitAny")]
 			[InlineData("WaitAll")]
-			public async Task SuccessCase_AfterWhenAny(string waitMethod)
+			public async Task WaitMethod_AfterWhenAny_DoesNotTrigger(string waitMethod)
 			{
-				var source = @$"
-using System.Threading.Tasks;
-using Xunit;
+				var source = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        var finishedTask = await Task.WhenAny(task1, task2);
+					        var finishedTask = await Task.WhenAny(task1, task2);
 
-        Task.{waitMethod}(finishedTask);
-    }}
-}}";
+					        Task.{0}(finishedTask);
+					    }}
+					}}
+					""", waitMethod);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -353,129 +368,135 @@ public async Task TestMethod() {{
 		public class GetAwaiterGetResult
 		{
 			[Fact]
-			public async Task FailureCase()
+			public async Task GetResult_Triggers()
 			{
-				var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Task.CompletedTask.GetAwaiter().[|GetResult()|];
-        Action<Task> _ = t => t.GetAwaiter().GetResult();
-        void LocalFunction() {
-            Task.CompletedTask.GetAwaiter().GetResult();
-        }
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System;
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        Task.CompletedTask.GetAwaiter().[|GetResult()|];
+					        Action<Task> _ = t => t.GetAwaiter().GetResult();
+					        void LocalFunction() {
+					            Task.CompletedTask.GetAwaiter().GetResult();
+					        }
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 			}
 
 			[Fact]
-			public async Task FailureCase_BeforeWhenAll()
+			public async Task GetResult_BeforeWhenAll_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task = Task.Delay(1);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task = Task.Delay(1);
 
-        task.GetAwaiter().[|GetResult()|];
+					        task.GetAwaiter().[|GetResult()|];
 
-        await Task.WhenAll(task);
-    }
-}";
+					        await Task.WhenAll(task);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task FailureCase_WhenAllForOtherTask()
+			public async Task GetResult_OnUnawaitedTask_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(new[] { task1 });
+					        await Task.WhenAll(new[] { task1 });
 
-        task1.GetAwaiter().GetResult();
-        task2.GetAwaiter().[|GetResult()|];
-    }
-}";
+					        task1.GetAwaiter().GetResult();
+					        task2.GetAwaiter().[|GetResult()|];
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_InContinueWithLambda()
+			public async Task GetResult_InLambda_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Task.CompletedTask.ContinueWith(x => x.GetAwaiter().GetResult());
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        Task.CompletedTask.ContinueWith(x => x.GetAwaiter().GetResult());
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAll()
+			public async Task GetResult_AfterWhenAll_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        await Task.WhenAll(task1, task2);
+					        await Task.WhenAll(task1, task2);
 
-        task1.GetAwaiter().GetResult();
-        task2.GetAwaiter().GetResult();
-    }
-}";
+					        task1.GetAwaiter().GetResult();
+					        task2.GetAwaiter().GetResult();
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAny()
+			public async Task GetResult_AfterWhenAny_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.Delay(1);
-        var task2 = Task.Delay(2);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.Delay(1);
+					        var task2 = Task.Delay(2);
 
-        var finishedTask = await Task.WhenAny(task1, task2);
+					        var finishedTask = await Task.WhenAny(task1, task2);
 
-        finishedTask.GetAwaiter().GetResult();
-    }
-}";
+					        finishedTask.GetAwaiter().GetResult();
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -487,131 +508,137 @@ public class Task_Generic
 		public class Result
 		{
 			[Fact]
-			public async Task FailureCase()
+			public async Task Result_Triggers()
 			{
-				var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = Task.FromResult(42).[|Result|];
-        Func<Task<int>, int> _2 = t => t.Result;
-        void LocalFunction() {
-            var _3 = Task.FromResult(42).Result;
-        }
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System;
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var _ = Task.FromResult(42).[|Result|];
+					        Func<Task<int>, int> _2 = t => t.Result;
+					        void LocalFunction() {
+					            var _3 = Task.FromResult(42).Result;
+					        }
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 			}
 
 			[Fact]
-			public async Task FailureCase_BeforeWhenAll()
+			public async Task Result_BeforeWhenAll_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task = Task.FromResult(42);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task = Task.FromResult(42);
 
-        Assert.Equal(42, task.[|Result|]);
+					        Assert.Equal(42, task.[|Result|]);
 
-        await Task.WhenAll(task);
-    }
-}";
+					        await Task.WhenAll(task);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task FailureCase_WhenAllForOtherTask()
+			public async Task Result_ForUnawaitedTask_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        await Task.WhenAll(new[] { task1 });
+					        await Task.WhenAll(new[] { task1 });
 
-        Assert.Equal(42, task1.Result);
-        Assert.Equal(2112, task2.[|Result|]);
-        Assert.Equal(2154, task1.Result + task2.[|Result|]);
-    }
-}";
+					        Assert.Equal(42, task1.Result);
+					        Assert.Equal(2112, task2.[|Result|]);
+					        Assert.Equal(2154, task1.Result + task2.[|Result|]);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_InContinueWithLambda()
+			public async Task Result_InLambda_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = Task.FromResult(42).ContinueWith(x => x.Result);
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var _ = Task.FromResult(42).ContinueWith(x => x.Result);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAll()
+			public async Task Result_AfterWhenAll_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        await Task.WhenAll(task1, task2);
+					        await Task.WhenAll(task1, task2);
 
-        Assert.Equal(42, task1.Result);
-        Assert.Equal(2112, task2.Result);
-        Assert.Equal(2154, task1.Result + task2.Result);
-    }
-}";
+					        Assert.Equal(42, task1.Result);
+					        Assert.Equal(2112, task2.Result);
+					        Assert.Equal(2154, task1.Result + task2.Result);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAny()
+			public async Task Result_AfterWhenAny_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        var finishedTask = await Task.WhenAny(task1, task2);
+					        var finishedTask = await Task.WhenAny(task1, task2);
 
-        Assert.Equal(2600, finishedTask.Result);
-    }
-}";
+					        Assert.Equal(2600, finishedTask.Result);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -620,131 +647,138 @@ public async Task TestMethod() {
 		public class GetAwaiterGetResult
 		{
 			[Fact]
-			public async Task FailureCase()
+			public async Task GetResult_Triggers()
 			{
-				var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = Task.FromResult(42).GetAwaiter().[|GetResult()|];
-        Func<Task<int>, int> _2 = t => t.GetAwaiter().GetResult();
-        void LocalFunction() {
-            var _3 = Task.FromResult(42).GetAwaiter().GetResult();
-        }
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System;
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var _ = Task.FromResult(42).GetAwaiter().[|GetResult()|];
+					        Func<Task<int>, int> _2 = t => t.GetAwaiter().GetResult();
+					        void LocalFunction() {
+					            var _3 = Task.FromResult(42).GetAwaiter().GetResult();
+					        }
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 			}
 
 			[Fact]
-			public async Task FailureCase_BeforeWhenAll()
+			public async Task GetResult_BeforeWhenAll_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task = Task.FromResult(42);
+					using System.Threading.Tasks;
+					using Xunit;
 
-        Assert.Equal(42, task.GetAwaiter().[|GetResult()|]);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task = Task.FromResult(42);
 
-        await Task.WhenAll(task);
-    }
-}";
+					        Assert.Equal(42, task.GetAwaiter().[|GetResult()|]);
+
+					        await Task.WhenAll(task);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task FailureCase_WhenAllForOtherTask()
+			public async Task GetResult_OnUnawaitedTask_Triggers()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        await Task.WhenAll(new[] { task1 });
+					        await Task.WhenAll(new[] { task1 });
 
-        Assert.Equal(42, task1.GetAwaiter().GetResult());
-        Assert.Equal(2112, task2.GetAwaiter().[|GetResult()|]);
-        Assert.Equal(2154, task1.GetAwaiter().GetResult() + task2.GetAwaiter().[|GetResult()|]);
-    }
-}";
+					        Assert.Equal(42, task1.GetAwaiter().GetResult());
+					        Assert.Equal(2112, task2.GetAwaiter().[|GetResult()|]);
+					        Assert.Equal(2154, task1.GetAwaiter().GetResult() + task2.GetAwaiter().[|GetResult()|]);
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_InContinueWithLambda()
+			public async Task GetResult_InLambda_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = Task.FromResult(42).ContinueWith(x => x.GetAwaiter().GetResult());
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var _ = Task.FromResult(42).ContinueWith(x => x.GetAwaiter().GetResult());
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAll()
+			public async Task GetResult_AfterWhenAll_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        await Task.WhenAll(task1, task2);
+					        await Task.WhenAll(task1, task2);
 
-        Assert.Equal(42, task1.GetAwaiter().GetResult());
-        Assert.Equal(2112, task2.GetAwaiter().GetResult());
-        Assert.Equal(2154, task1.GetAwaiter().GetResult() + task2.GetAwaiter().GetResult());
-    }
-}";
+					        Assert.Equal(42, task1.GetAwaiter().GetResult());
+					        Assert.Equal(2112, task2.GetAwaiter().GetResult());
+					        Assert.Equal(2154, task1.GetAwaiter().GetResult() + task2.GetAwaiter().GetResult());
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
 
 			[Fact]
-			public async Task SuccessCase_AfterWhenAny()
+			public async Task GetResult_AfterWhenAny_DoesNotTrigger()
 			{
-				var source = @"
-using System.Threading.Tasks;
-using Xunit;
+				var source = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
 
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var task1 = Task.FromResult(42);
-        var task2 = Task.FromResult(2112);
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var task1 = Task.FromResult(42);
+					        var task2 = Task.FromResult(2112);
 
-        var finishedTask = await Task.WhenAny(task1, task2);
+					        var finishedTask = await Task.WhenAny(task1, task2);
 
-        Assert.Equal(2600, finishedTask.GetAwaiter().GetResult());
-    }
-}";
+					        Assert.Equal(2600, finishedTask.GetAwaiter().GetResult());
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -754,23 +788,24 @@ public async Task TestMethod() {
 	public class ValueTask_NonGeneric
 	{
 		[Fact]
-		public async Task FailureCase_GetAwaiterGetResult()
+		public async Task GetResult_Triggers()
 		{
-			var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        default(ValueTask).GetAwaiter().[|GetResult()|];
-        Action<ValueTask> _ = vt => vt.GetAwaiter().GetResult();
-        void LocalFunction() {
-            default(ValueTask).GetAwaiter().GetResult();
-        }
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        default(ValueTask).GetAwaiter().[|GetResult()|];
+				        Action<ValueTask> _ = vt => vt.GetAwaiter().GetResult();
+				        void LocalFunction() {
+				            default(ValueTask).GetAwaiter().GetResult();
+				        }
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
@@ -779,45 +814,47 @@ void LocalFunction() {
 	public class ValueTask_Generic
 	{
 		[Fact]
-		public async Task FailureCase_Result()
+		public async Task Result_Triggers()
 		{
-			var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = new ValueTask<int>(42).[|Result|];
-        Func<ValueTask<int>, int> _2 = vt => vt.Result;
-        void LocalFunction() {
-            var _3 = new ValueTask<int>(42).Result;
-        }
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        var _ = new ValueTask<int>(42).[|Result|];
+				        Func<ValueTask<int>, int> _2 = vt => vt.Result;
+				        void LocalFunction() {
+				            var _3 = new ValueTask<int>(42).Result;
+				        }
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
 
 		[Fact]
-		public async Task FailureCase_GetAwaiterGetResult()
+		public async Task GetResult_Triggers()
 		{
-			var source = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var _ = new ValueTask<int>(42).GetAwaiter().[|GetResult()|];
-        Func<ValueTask<int>, int> _2 = vt => vt.GetAwaiter().GetResult();
-        void LocalFunction() {
-            var _3 = new ValueTask<int>(42).GetAwaiter().GetResult();
-        }
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        var _ = new ValueTask<int>(42).GetAwaiter().[|GetResult()|];
+				        Func<ValueTask<int>, int> _2 = vt => vt.GetAwaiter().GetResult();
+				        void LocalFunction() {
+				            var _3 = new ValueTask<int>(42).GetAwaiter().GetResult();
+				        }
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseConfigureAwaitTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseConfigureAwaitTests.cs
index f2323167..9a55c7d4 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseConfigureAwaitTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/DoNotUseConfigureAwaitTests.cs
@@ -8,16 +8,17 @@ public class DoNotUseConfigureAwaitTests
 	[Fact]
 	public async Task NoCall_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        await Task.Delay(1);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async Task TestMethod() {
+			        await Task.Delay(1);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -27,15 +28,16 @@ public class ConfigureAwait_Boolean
 		[Fact]
 		public async Task NonTestMethod_DoesNotTrigger()
 		{
-			var source = @"
-using System.Threading.Tasks;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
 
-public class NonTestClass {
-    public async Task NonTestMethod() {
-        await Task.Delay(1).ConfigureAwait(false);
-    }
-}";
+				public class NonTestClass {
+				    public async Task NonTestMethod() {
+				        await Task.Delay(1).ConfigureAwait(false);
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -43,46 +45,48 @@ public async Task NonTestMethod() {
 		[Fact]
 		public async Task True_DoesNotTrigger()
 		{
-			var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        await Task.Delay(1).ConfigureAwait(true);
-    }
-}";
+			var source = /* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {
+				    [Fact]
+				    public async Task TestMethod() {
+				        await Task.Delay(1).ConfigureAwait(true);
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
-		public static TheoryData<string> InvalidValues = new()
-		{
+		public static TheoryData<string> InvalidValues =
+		[
 			"false",       // Literal false
 			"1 == 2",      // Logical false (we don't compute)
 			"1 == 1",      // Logical true (we don't compute)
 			"booleanVar",  // Reference value (we don't do lookup)
-		};
+		];
 
 		[Theory]
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_InsideLambda_DoesNotTrigger(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var t = Task.Run(async () => {{
-            await Task.Delay(1).ConfigureAwait({argumentValue});
-        }});
-        await t;
-    }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        var t = Task.Run(async () => {{
+				            await Task.Delay(1).ConfigureAwait({0});
+				        }});
+				        await t;
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -91,19 +95,20 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_InsideLocalFunction_DoesNotTrigger(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        async Task AssertEventStateAsync() {{
-            await Task.Delay(1).ConfigureAwait({argumentValue});
-        }}
-    }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        async Task AssertEventStateAsync() {{
+				            await Task.Delay(1).ConfigureAwait({0});
+				        }}
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
@@ -112,22 +117,19 @@ async Task AssertEventStateAsync() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskWithAwait_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        await Task.Delay(1).ConfigureAwait({argumentValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(9, 29, 9, 45 + argumentValue.Length)
-					.WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        await Task.Delay(1).{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -136,22 +138,19 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskWithoutAwait_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var booleanVar = true;
-        Task.Delay(1).ConfigureAwait({argumentValue}).GetAwaiter().GetResult();
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(9, 23, 9, 39 + argumentValue.Length)
-					.WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var booleanVar = true;
+				        Task.Delay(1).{{|#0:ConfigureAwait({0})|}}.GetAwaiter().GetResult();
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -160,23 +159,20 @@ public void TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskOfT_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var task = Task.FromResult(42);
-        await task.ConfigureAwait({argumentValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(10, 20, 10, 36 + argumentValue.Length)
-					.WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        var task = Task.FromResult(42);
+				        await task.{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -185,23 +181,20 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_ValueTask_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask);
-        await valueTask.ConfigureAwait({argumentValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(10, 25, 10, 41 + argumentValue.Length)
-					.WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        var valueTask = default(ValueTask);
+				        await valueTask.{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -210,23 +203,20 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_ValueTaskOfT_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask<int>);
-        await valueTask.ConfigureAwait({argumentValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(10, 25, 10, 41 + argumentValue.Length)
-					.WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var booleanVar = true;
+				        var valueTask = default(ValueTask<int>);
+				        await valueTask.{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Omit ConfigureAwait, or use ConfigureAwait(true) to avoid CA2007.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -239,15 +229,16 @@ public class ConfigureAwait_ConfigureAwaitOptions
 		[Fact]
 		public async Task NonTestMethod_DoesNotTrigger()
 		{
-			var source = @"
-using System.Threading.Tasks;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
 
-public class NonTestClass {
-    public async Task NonTestMethod() {
-        await Task.Delay(1).ConfigureAwait(ConfigureAwaitOptions.None);
-    }
-}";
+				public class NonTestClass {
+				    public async Task NonTestMethod() {
+				        await Task.Delay(1).ConfigureAwait(ConfigureAwaitOptions.None);
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -258,48 +249,50 @@ public async Task NonTestMethod() {
 		[InlineData("ConfigureAwaitOptions.ForceYielding | ConfigureAwaitOptions.SuppressThrowing | ConfigureAwaitOptions.ContinueOnCapturedContext")]
 		public async Task ValidValue_DoesNotTrigger(string enumValue)
 		{
-			var source = $@"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        await Task.Delay(1).ConfigureAwait({enumValue});
-    }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        await Task.Delay(1).ConfigureAwait({0});
+				    }}
+				}}
+				""", enumValue);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
-		public static TheoryData<string> InvalidValues = new()
-		{
+		public static TheoryData<string> InvalidValues =
+		[
 			// Literal values
 			"ConfigureAwaitOptions.None",
 			"ConfigureAwaitOptions.SuppressThrowing",
 			"ConfigureAwaitOptions.ForceYielding | ConfigureAwaitOptions.SuppressThrowing",
 			// Reference values (we don't do lookup)
 			"enumVar",
-		};
+		];
 
 		[Theory]
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_InsideLambda_DoesNotTrigger(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        var t = Task.Run(async () => {{
-            await Task.Delay(1).ConfigureAwait({argumentValue});
-        }});
-        await t;
-    }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        var t = Task.Run(async () => {{
+				            await Task.Delay(1).ConfigureAwait({0});
+				        }});
+				        await t;
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -308,19 +301,20 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_InsideLocalFunction_DoesNotTrigger(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        async Task AssertEventStateAsync() {{
-            await Task.Delay(1).ConfigureAwait({argumentValue});
-        }}
-    }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        async Task AssertEventStateAsync() {{
+				            await Task.Delay(1).ConfigureAwait({0});
+				        }}
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, source);
 		}
@@ -329,22 +323,19 @@ async Task AssertEventStateAsync() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskWithAwait_Triggers(string enumValue)
 		{
-			var source = $@"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        await Task.Delay(1).ConfigureAwait({enumValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(9, 29, 9, 45 + enumValue.Length)
-					.WithArguments(enumValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        await Task.Delay(1).{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", enumValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(enumValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -353,22 +344,19 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskWithoutAwait_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        Task.Delay(1).ConfigureAwait({argumentValue}).GetAwaiter().GetResult();
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(9, 23, 9, 39 + argumentValue.Length)
-					.WithArguments(argumentValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        Task.Delay(1).{{|#0:ConfigureAwait({0})|}}.GetAwaiter().GetResult();
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -377,23 +365,20 @@ public void TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task InvalidValue_TaskOfT_Triggers(string argumentValue)
 		{
-			var source = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        var task = Task.FromResult(42);
-        await task.ConfigureAwait({argumentValue});
-    }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(10, 20, 10, 36 + argumentValue.Length)
-					.WithArguments(argumentValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        var task = Task.FromResult(42);
+				        await task.{{|#0:ConfigureAwait({0})|}};
+				    }}
+				}}
+				""", argumentValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments(argumentValue, "Ensure ConfigureAwaitOptions.ContinueOnCapturedContext in the flags.");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/EnsureFixturesHaveASourceTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/EnsureFixturesHaveASourceTests.cs
index 1b330201..ba1cb0c4 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/EnsureFixturesHaveASourceTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/EnsureFixturesHaveASourceTests.cs
@@ -9,10 +9,11 @@ public class NonTestClass
 		[Fact]
 		public async Task DoesNotTrigger()
 		{
-			var source = @"
-public class NonTestClass {
-    public NonTestClass(object _) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class NonTestClass {
+				    public NonTestClass(object _) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -23,17 +24,18 @@ public class SupportedNonFixtureData
 		[Theory]
 		[InlineData("")]
 		[InlineData("[Collection(\"TestCollection\")]")]
-		public async Task V2SupportedTypes(string attribute)
+		public async Task SupportedTypes_V2_DoesNotTrigger(string attribute)
 		{
-			var source = $@"
-using Xunit;
-using Xunit.Abstractions;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using Xunit.Abstractions;
 
-{attribute} public class TestClass {{
-    public TestClass(ITestOutputHelper _) {{ }}
+				{0} public class TestClass {{
+				    public TestClass(ITestOutputHelper _) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", attribute);
 
 			await Verify.VerifyAnalyzerV2(source);
 		}
@@ -41,18 +43,18 @@ [Fact] public void TestMethod() {{ }}
 		[Theory]
 		[InlineData("")]
 		[InlineData("[Collection(\"TestCollection\")]")]
-		public async Task V3SupportedTypes(string attribute)
+		public async Task SupportedTypes_V3_DoesNotTrigger(string attribute)
 		{
-			// TODO: This will need to be updated when v3 names are finalized
-			var source = $@"
-using Xunit;
-using Xunit.v3;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using Xunit.v3;
 
-{attribute} public class TestClass {{
-    public TestClass(ITestOutputHelper _1, ITestContextAccessor _2) {{ }}
+				{0} public class TestClass {{
+				    public TestClass(ITestOutputHelper _1, ITestContextAccessor _2) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", attribute);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -60,14 +62,15 @@ [Fact] public void TestMethod() {{ }}
 		[Fact]
 		public async Task OptionalParameter_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-    public TestClass(bool value = true) { }
+				public class TestClass {
+				    public TestClass(bool value = true) { }
 
-    [Fact] public void TestMethod() { }
-}";
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -92,25 +95,25 @@ public class ClassFixtures
 		[InlineData(
 			"[Collection(\"TestCollection\")]", "",
 			"", ", IClassFixture<object>")]
-		public async Task SupportsDerivation(
+		public async Task BaseClassParameter_DerivedClassFixture_DoesNotTrigger(
 			string baseAttribute,
 			string baseInterface,
 			string derivedAttribute,
 			string derivedInterface)
 		{
-			var source = @$"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-{baseAttribute}
-public abstract class BaseClass {baseInterface} {{
-}}
+				{0}
+				public abstract class BaseClass {1} {{ }}
 
-{derivedAttribute}
-public class TestClass : BaseClass {derivedInterface} {{
-    public TestClass(object _) {{ }}
+				{2}
+				public class TestClass : BaseClass {3} {{
+				    public TestClass(object _) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", baseAttribute, baseInterface, derivedAttribute, derivedInterface);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -118,18 +121,19 @@ [Fact] public void TestMethod() {{ }}
 		[Fact]
 		public async Task ClassFixtureOnCollectionDefinition_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection : IClassFixture<object> { }
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection : IClassFixture<object> { }
 
-[Collection(nameof(TestCollection))]
-public class TestClass {
-    public TestClass(object _) { }
+				[Collection(nameof(TestCollection))]
+				public class TestClass {
+				    public TestClass(object _) { }
 
-    [Fact] public void TestMethod() { }
-}";
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -137,21 +141,17 @@ [Fact] public void TestMethod() { }
 		[Fact]
 		public async Task MissingClassFixtureDefinition_Triggers()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-    public TestClass(object _) { }
+				public class TestClass {
+				    public TestClass(object [|_|]) { }
 
-    [Fact] public void TestMethod() { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 29, 5, 30)
-					.WithArguments("_");
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
@@ -162,16 +162,17 @@ public class CollectionFixtures
 		[InlineData("[CollectionDefinition(nameof(TestCollection))]")]
 		public async Task NoFixture_DoesNotTrigger(string definitionAttribute)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-{definitionAttribute}
-public class TestCollection {{ }}
+				{0}
+				public class TestCollection {{ }}
 
-[Collection(nameof(TestCollection))]
-public class TestClass {{
-    [Fact] public void TestMethod() {{ }}
-}}";
+				[Collection(nameof(TestCollection))]
+				public class TestClass {{
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", definitionAttribute);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -179,25 +180,26 @@ [Fact] public void TestMethod() {{ }}
 		[Fact]
 		public async Task WithInheritedFixture_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class Fixture { }
+				public class Fixture { }
 
-[CollectionDefinition(""test"")]
-public class TestCollection : ICollectionFixture<Fixture> { }
+				[CollectionDefinition("test")]
+				public class TestCollection : ICollectionFixture<Fixture> { }
 
-public abstract class TestContext {
-    protected TestContext(Fixture fixture) { }
-}
+				public abstract class TestContext {
+				    protected TestContext(Fixture fixture) { }
+				}
 
-[Collection(""test"")]
-public class TestClass : TestContext {
-    public TestClass(Fixture fixture) : base(fixture) { }
+				[Collection("test")]
+				public class TestClass : TestContext {
+				    public TestClass(Fixture fixture) : base(fixture) { }
 
-    [Fact]
-    public void TestMethod() { }
-}";
+				    [Fact]
+				    public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -205,27 +207,23 @@ public void TestMethod() { }
 		[Fact]
 		public async Task WithGenericFixture_TriggersWithV2_DoesNotTriggerWithV3()
 		{
-			var source = @"
-using Xunit;
-
-public class Fixture<T> { }
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-[CollectionDefinition(""test"")]
-public class TestCollection<TCollectionFixture> : ICollectionFixture<Fixture<TCollectionFixture>> { }
+				public class Fixture<T> { }
 
-[Collection(""test"")]
-public class TestClass {
-    public TestClass(Fixture<int> fixture) { }
+				[CollectionDefinition("test")]
+				public class TestCollection<TCollectionFixture> : ICollectionFixture<Fixture<TCollectionFixture>> { }
 
-    [Fact]
-    public void TestMethod() { }
-}";
+				[Collection("test")]
+				public class TestClass {
+				    public TestClass(Fixture<int> {|#0:fixture|}) { }
 
-			var expectedV2 =
-				Verify
-					.Diagnostic()
-					.WithSpan(11, 35, 11, 42)
-					.WithArguments("fixture");
+				    [Fact]
+				    public void TestMethod() { }
+				}
+				""";
+			var expectedV2 = Verify.Diagnostic().WithLocation(0).WithArguments("fixture");
 
 			await Verify.VerifyAnalyzerV2(source, expectedV2);
 			await Verify.VerifyAnalyzerV3(source);
@@ -234,31 +232,27 @@ public void TestMethod() { }
 		[Fact]
 		public async Task WithInheritedGenericFixture_TriggersWithV2_DoesNotTriggerWithV3()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class Fixture<T> { }
+				public class Fixture<T> { }
 
-[CollectionDefinition(""test"")]
-public class TestCollection<TCollectionFixture> : ICollectionFixture<Fixture<TCollectionFixture>> { }
+				[CollectionDefinition("test")]
+				public class TestCollection<TCollectionFixture> : ICollectionFixture<Fixture<TCollectionFixture>> { }
 
-[Collection(""test"")]
-public abstract class TestContext<TContextFixture> {
-    protected TestContext(Fixture<TContextFixture> fixture) { }
-}
-
-public class TestClass : TestContext<int> {
-    public TestClass(Fixture<int> fixture) : base(fixture) { }
+				[Collection("test")]
+				public abstract class TestContext<TContextFixture> {
+				    protected TestContext(Fixture<TContextFixture> fixture) { }
+				}
 
-    [Fact]
-    public void TestMethod() { }
-}";
+				public class TestClass : TestContext<int> {
+				    public TestClass(Fixture<int> {|#0:fixture|}) : base(fixture) { }
 
-			var expectedV2 =
-				Verify
-					.Diagnostic()
-					.WithSpan(15, 35, 15, 42)
-					.WithArguments("fixture");
+				    [Fact]
+				    public void TestMethod() { }
+				}
+				""";
+			var expectedV2 = Verify.Diagnostic().WithLocation(0).WithArguments("fixture");
 
 			await Verify.VerifyAnalyzerV2(source, expectedV2);
 			await Verify.VerifyAnalyzerV3(source);
@@ -271,20 +265,20 @@ public async Task WithFixture_SupportsDerivation(
 			string baseAttribute,
 			string derivedAttribute)
 		{
-			var source = @$"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection : ICollectionFixture<object> {{ }}
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection : ICollectionFixture<object> {{ }}
 
-{baseAttribute}
-public abstract class BaseClass {{
-}}
+				{0}
+				public abstract class BaseClass {{ }}
 
-{derivedAttribute}
-public class TestClass : BaseClass {{
-    public TestClass(object _) {{ }}
-}}";
+				{1}
+				public class TestClass : BaseClass {{
+				    public TestClass(object _) {{ }}
+				}}
+				""", baseAttribute, derivedAttribute);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -292,18 +286,19 @@ public TestClass(object _) {{ }}
 		[Fact]
 		public async Task WithFixture_WithDefinition_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection : ICollectionFixture<object> { }
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection : ICollectionFixture<object> { }
 
-[Collection(nameof(TestCollection))]
-public class TestClass {
-    public TestClass(object _) { }
+				[Collection(nameof(TestCollection))]
+				public class TestClass {
+				    public TestClass(object _) { }
 
-    [Fact] public void TestMethod() { }
-}";
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -313,25 +308,21 @@ [Fact] public void TestMethod() { }
 		[InlineData("[CollectionDefinition(nameof(TestCollection))]")]
 		public async Task WithFixture_WithoutCollectionFixtureInterface_Triggers(string definitionAttribute)
 		{
-			var source = @$"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-{definitionAttribute}
-public class TestCollection {{ }}
+				{0}
+				public class TestCollection {{ }}
 
-[Collection(nameof(TestCollection))]
-public class TestClass {{
-    public TestClass(object _) {{ }}
+				[Collection(nameof(TestCollection))]
+				public class TestClass {{
+				    public TestClass(object [|_|]) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(9, 29, 9, 30)
-					.WithArguments("_");
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", definitionAttribute);
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
@@ -340,16 +331,17 @@ public class AssemblyFixtures
 		[Fact]
 		public async Task WithAssemblyFixture_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-[assembly: AssemblyFixture(typeof(object))]
+				[assembly: AssemblyFixture(typeof(object))]
 
-public class TestClass {
-    public TestClass(object _) { }
+				public class TestClass {
+				    public TestClass(object _) { }
 
-    [Fact] public void TestMethod() { }
-}";
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -362,18 +354,19 @@ public class MixedFixtures
 		[InlineData("[CollectionDefinition(nameof(TestCollection))]")]
 		public async Task WithClassFixture_WithCollection_DoesNotTrigger(string definitionAttribute)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-{definitionAttribute}
-public class TestCollection {{ }}
+				{0}
+				public class TestCollection {{ }}
 
-[Collection(nameof(TestCollection))]
-public class TestClass : IClassFixture<object> {{
-    public TestClass(object _) {{ }}
+				[Collection(nameof(TestCollection))]
+				public class TestClass : IClassFixture<object> {{
+				    public TestClass(object _) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""", definitionAttribute);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -381,78 +374,71 @@ [Fact] public void TestMethod() {{ }}
 		[Fact]
 		public async Task WithMixedClassAndCollectionFixture_AndSupportedNonFixture_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var sourceTemplate = /* lang=c#-test */ """
+				using Xunit;
 
-public class ClassFixture {{ }}
-public class CollectionFixture {{ }}
+				public class ClassFixture {{ }}
+				public class CollectionFixture {{ }}
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection : ICollectionFixture<CollectionFixture> {{ }}
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection : ICollectionFixture<CollectionFixture> {{ }}
 
-[Collection(nameof(TestCollection))]
-public class TestClass : IClassFixture<ClassFixture> {{
-    public TestClass(ClassFixture _1, CollectionFixture _2, {0} _3) {{ }}
+				[Collection(nameof(TestCollection))]
+				public class TestClass : IClassFixture<ClassFixture> {{
+				    public TestClass(ClassFixture _1, CollectionFixture _2, {0} _3) {{ }}
 
-    [Fact] public void TestMethod() {{ }}
-}}";
+				    [Fact] public void TestMethod() {{ }}
+				}}
+				""";
 
-			await Verify.VerifyAnalyzerV2(string.Format(source, "Xunit.Abstractions.ITestOutputHelper"));
-			await Verify.VerifyAnalyzerV3(string.Format(source, "Xunit.ITestContextAccessor"));
+			await Verify.VerifyAnalyzerV2(string.Format(sourceTemplate, "Xunit.Abstractions.ITestOutputHelper"));
+			await Verify.VerifyAnalyzerV3(string.Format(sourceTemplate, "Xunit.ITestContextAccessor"));
 		}
 
 		[Fact]
 		public async Task MissingClassFixture_Triggers()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class ClassFixture { }
-public class CollectionFixture { }
+				public class ClassFixture { }
+				public class CollectionFixture { }
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection : ICollectionFixture<CollectionFixture> { }
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection : ICollectionFixture<CollectionFixture> { }
 
-[Collection(nameof(TestCollection))]
-public class TestClass {
-    public TestClass(ClassFixture _1, CollectionFixture _2) { }
+				[Collection(nameof(TestCollection))]
+				public class TestClass {
+				    public TestClass(ClassFixture [|_1|], CollectionFixture _2) { }
 
-    [Fact] public void TestMethod() { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(12, 35, 12, 37)
-					.WithArguments("_1");
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
 		public async Task MissingCollectionFixture_Triggers()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class ClassFixture { }
-public class CollectionFixture { }
+				public class ClassFixture { }
+				public class CollectionFixture { }
 
-[CollectionDefinition(nameof(TestCollection))]
-public class TestCollection { }
+				[CollectionDefinition(nameof(TestCollection))]
+				public class TestCollection { }
 
-[Collection(nameof(TestCollection))]
-public class TestClass : IClassFixture<ClassFixture> {
-    public TestClass(ClassFixture _1, CollectionFixture _2) { }
+				[Collection(nameof(TestCollection))]
+				public class TestClass : IClassFixture<ClassFixture> {
+				    public TestClass(ClassFixture _1, CollectionFixture [|_2|]) { }
 
-    [Fact] public void TestMethod() { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(12, 57, 12, 59)
-					.WithArguments("_2");
+				    [Fact] public void TestMethod() { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodMustNotHaveParametersTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodMustNotHaveParametersTests.cs
index 15c5d65f..4e64e254 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodMustNotHaveParametersTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodMustNotHaveParametersTests.cs
@@ -5,42 +5,41 @@
 public class FactMethodMustNotHaveParametersTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForFactWithNoParameters()
+	public async Task FactWithNoParameters_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryWithParameters()
+	public async Task TheoryWithParameters_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(string p) { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(string p) { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsErrorForFactWithParameter()
+	public async Task FactWithParameters_Triggers()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod(string p) { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27);
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void [|TestMethod|](string p) { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodShouldNotHaveTestDataTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodShouldNotHaveTestDataTests.cs
index c87d3cb1..41f41d5a 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodShouldNotHaveTestDataTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/FactMethodShouldNotHaveTestDataTests.cs
@@ -5,13 +5,14 @@
 public class FactMethodShouldNotHaveTestDataTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForFactMethodWithNoDataAttributes()
+	public async Task FactWithNoDataAttributes_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -20,14 +21,15 @@ public void TestMethod() { }
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task DoesNotFindErrorForTheoryMethodWithDataAttributes(string dataAttribute)
+	public async Task TheoryWithDataAttributes_DoesNotTrigger(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.Theory]
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", dataAttribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -36,36 +38,34 @@ public void TestMethod() {{ }}
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task DoesNotFindErrorForDerivedFactMethodWithDataAttributes(string dataAttribute)
+	public async Task FactDerivedMethodWithDataAttributes_DoesNotTrigger(string dataAttribute)
 	{
-		var source1 = "public class DerivedFactAttribute: Xunit.FactAttribute {}";
-		var source2 = $@"
-public class TestClass {{
-    [DerivedFactAttribute]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source1 = /* lang=c#-test */ "public class DerivedFactAttribute: Xunit.FactAttribute {}";
+		var source2 = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [DerivedFactAttribute]
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", dataAttribute);
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 });
+		await Verify.VerifyAnalyzer([source1, source2]);
 	}
 
 	[Theory]
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task FindsErrorForFactMethodsWithDataAttributes(string dataAttribute)
+	public async Task FactWithDataAttributes_Triggers(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.Fact]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 17, 5, 27);
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.Fact]
+			    [Xunit.{0}]
+			    public void [|TestMethod|]() {{ }}
+			}}
+			""", dataAttribute);
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
index ce73a8a5..bc3d0c86 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
@@ -4,7 +4,6 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.Testing;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.InlineDataMustMatchTheoryParameters>;
@@ -17,12 +16,13 @@ public class NonErrors
 		[Fact]
 		public async Task MethodUsingParamsArgument()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"", ""xyz"")]
-    public void TestMethod(params string[] args) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc", "xyz")]
+				    public void TestMethod(params string[] args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -30,12 +30,13 @@ public void TestMethod(params string[] args) { }
 		[Fact]
 		public async Task MethodUsingNullParamsArgument_NonNullable()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(null)]
-    public void TestMethod(params string[] args) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(null)]
+				    public void TestMethod(params string[] args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -43,14 +44,15 @@ public void TestMethod(params string[] args) { }
 		[Fact]
 		public async Task MethodUsingNullParamsArgument_Nullable()
 		{
-			var source = @"
-#nullable enable
+			var source = /* lang=c#-test */ """
+				#nullable enable
 
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(null)]
-    public void TestMethod(params string[]? args) { }
-}";
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(null)]
+				    public void TestMethod(params string[]? args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp9, source);
 		}
@@ -58,12 +60,13 @@ public void TestMethod(params string[]? args) { }
 		[Fact]
 		public async Task MethodUsingNormalAndParamsArgument()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"", ""xyz"")]
-    public void TestMethod(string first, params string[] args) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc", "xyz")]
+				    public void TestMethod(string first, params string[] args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -71,12 +74,13 @@ public void TestMethod(string first, params string[] args) { }
 		[Fact]
 		public async Task MethodUsingNormalAndNullParamsArgument_NonNullable()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"", null)]
-    public void TestMethod(string first, params string[] args) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc", null)]
+				    public void TestMethod(string first, params string[] args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -84,14 +88,15 @@ public void TestMethod(string first, params string[] args) { }
 		[Fact]
 		public async Task MethodUsingNormalAndNullParamsArgument_Nullable()
 		{
-			var source = @"
-#nullable enable
+			var source = /* lang=c#-test */ """
+				#nullable enable
 
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"", null)]
-    public void TestMethod(string first, params string[]? args) { }
-}";
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc", null)]
+				    public void TestMethod(string first, params string[]? args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp9, source);
 		}
@@ -99,12 +104,13 @@ public void TestMethod(string first, params string[]? args) { }
 		[Fact]
 		public async Task MethodUsingNormalAndUnusedParamsArgument()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"")]
-    public void TestMethod(string first, params string[] args) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc")]
+				    public void TestMethod(string first, params string[] args) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -112,12 +118,13 @@ public void TestMethod(string first, params string[] args) { }
 		[Fact]
 		public async Task MethodUsingEmptyArrayForParams()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new int[] { })]
-    public void VariableArgumentsTest(params int[] sq) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new int[] { })]
+				    public void VariableArgumentsTest(params int[] sq) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -125,12 +132,13 @@ public void VariableArgumentsTest(params int[] sq) { }
 		[Fact]
 		public async Task MethodUsingMixedArgumentsAndEmptyArrayForParams()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(21.12, new int[] { })]
-    public void VariableArgumentsTest(double d, params int[] sq) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(21.12, new int[] { })]
+				    public void VariableArgumentsTest(double d, params int[] sq) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -138,12 +146,13 @@ public void VariableArgumentsTest(double d, params int[] sq) { }
 		[Fact]
 		public async Task MethodUsingNonEmptyArrayForParams()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new int[] { 1, 2, 3 })]
-    public void VariableArgumentsTest(params int[] sq) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new int[] { 1, 2, 3 })]
+				    public void VariableArgumentsTest(params int[] sq) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -151,25 +160,13 @@ public void VariableArgumentsTest(params int[] sq) { }
 		[Fact]
 		public async Task MethodUsingMixedArgumentsAndNonEmptyArrayForParams()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(21.12, new int[] { 1, 2, 3 })]
-    public void VariableArgumentsTest(double d, params int[] sq) { }
-}";
-
-			await Verify.VerifyAnalyzer(source);
-		}
-
-		[Fact]
-		public async Task MethodUsingIncompatibleExplicitArrayForParams()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(21.12, {|xUnit1010:new object[] { }|})]
-    public void VariableArgumentsTest(double d, params int[] sq) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(21.12, new int[] { 1, 2, 3 })]
+				    public void VariableArgumentsTest(double d, params int[] sq) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -177,12 +174,13 @@ public void VariableArgumentsTest(double d, params int[] sq) { }
 		[Fact]
 		public async Task UsingParameters()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"", 1, null)]
-    public void TestMethod(string a, int b, object c) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc", 1, null)]
+				    public void TestMethod(string a, int b, object c) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -190,12 +188,13 @@ public void TestMethod(string a, int b, object c) { }
 		[Fact]
 		public async Task UsingParametersWithDefaultValues()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"")]
-    public void TestMethod(string a, string b = ""default"", string c = null) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc")]
+				    public void TestMethod(string a, string b = "default", string c = null) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -203,12 +202,13 @@ public void TestMethod(string a, string b = ""default"", string c = null) { }
 		[Fact]
 		public async Task UsingParametersWithDefaultValuesAndParamsArgument()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"")]
-    public void TestMethod(string a, string b = ""default"", string c = null, params string[] d) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc")]
+				    public void TestMethod(string a, string b = "default", string c = null, params string[] d) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -216,12 +216,13 @@ public void TestMethod(string a, string b = ""default"", string c = null, params
 		[Fact]
 		public async Task UsingParameterWithOptionalAttribute()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(""abc"")]
-    public void TestMethod(string a, [System.Runtime.InteropServices.Optional] string b) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData("abc")]
+				    public void TestMethod(string a, [System.Runtime.InteropServices.Optional] string b) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -229,15 +230,16 @@ public void TestMethod(string a, [System.Runtime.InteropServices.Optional] strin
 		[Fact]
 		public async Task UsingMultipleParametersWithOptionalAttributes()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData]
-    [Xunit.InlineData(""abc"")]
-    [Xunit.InlineData(""abc"", ""def"")]
-    public void TestMethod([System.Runtime.InteropServices.Optional] string a,
-                           [System.Runtime.InteropServices.Optional] string b) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData]
+				    [Xunit.InlineData("abc")]
+				    [Xunit.InlineData("abc", "def")]
+				    public void TestMethod([System.Runtime.InteropServices.Optional] string a,
+				                           [System.Runtime.InteropServices.Optional] string b) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -245,12 +247,13 @@ public void TestMethod([System.Runtime.InteropServices.Optional] string a,
 		[Fact]
 		public async Task UsingExplicitArray()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new object[] { ""abc"", 1, null })]
-    public void TestMethod(string a, int b, object c) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new object[] { "abc", 1, null })]
+				    public void TestMethod(string a, int b, object c) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -258,12 +261,13 @@ public void TestMethod(string a, int b, object c) { }
 		[Fact]
 		public async Task UsingExplicitNamedArray()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(data: new object[] { ""abc"", 1, null })]
-    public void TestMethod(string a, int b, object c) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(data: new object[] { "abc", 1, null })]
+				    public void TestMethod(string a, int b, object c) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -271,12 +275,13 @@ public void TestMethod(string a, int b, object c) { }
 		[Fact]
 		public async Task UsingImplicitArray()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new[] { (object)""abc"", 1, null })]
-    public void TestMethod(string a, int b, object c) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new[] { (object)"abc", 1, null })]
+				    public void TestMethod(string a, int b, object c) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -284,12 +289,13 @@ public void TestMethod(string a, int b, object c) { }
 		[Fact]
 		public async Task UsingImplicitNamedArray()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(data: new[] { (object)""abc"", 1, null })]
-    public void TestMethod(string a, int b, object c) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(data: new[] { (object)"abc", 1, null })]
+				    public void TestMethod(string a, int b, object c) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -297,12 +303,13 @@ public void TestMethod(string a, int b, object c) { }
 		[Fact]
 		public async Task EmptyArray()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new byte[0])]
-    public void TestMethod(byte[] input) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new byte[0])]
+				    public void TestMethod(byte[] input) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -313,12 +320,13 @@ public class X1009_TooFewValues
 		[Fact]
 		public async Task IgnoresFact()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.InlineData]
-    public void TestMethod(string a) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    [Xunit.InlineData]
+				    public void TestMethod(string a) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -328,64 +336,66 @@ public void TestMethod(string a) { }
 		[InlineData("Xunit.InlineData")]
 		public async Task NoArguments(string attribute)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [{attribute}]
-    public void TestMethod(int a) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1009")
-					.WithSpan(4, 6, 4, 6 + attribute.Length)
-					.WithSeverity(DiagnosticSeverity.Error);
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [{{|xUnit1009:{0}|}}]
+				    public void TestMethod(int a) {{ }}
+				}}
+				""", attribute);
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
 		public async Task TooFewArguments()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(1)]
-    public void TestMethod(int a, int b, string c) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1009")
-					.WithSpan(4, 6, 4, 25)
-					.WithSeverity(DiagnosticSeverity.Error);
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [{|xUnit1009:Xunit.InlineData(1)|}]
+				    public void TestMethod(int a, int b, string c) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
 		public async Task TooFewArguments_WithParams()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(1)]
-    public void TestMethod(int a, int b, params string[] value) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1009")
-					.WithSpan(4, 6, 4, 25)
-					.WithSeverity(DiagnosticSeverity.Error);
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [{|xUnit1009:Xunit.InlineData(1)|}]
+				    public void TestMethod(int a, int b, params string[] value) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
 	public class X1010_IncompatibleValueType
 	{
+		[Fact]
+		public async Task MethodUsingIncompatibleExplicitArrayForParams()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(21.12, {|xUnit1010:new object[] { }|})]
+				    public void VariableArgumentsTest(double d, params int[] sq) { }
+				}
+				""";
+
+			await Verify.VerifyAnalyzer(source);
+		}
+
 		public class NumericParameter : X1010_IncompatibleValueType
 		{
-			public static readonly TheoryData<string> NumericTypes = new()
-			{
+			public static readonly TheoryData<string> NumericTypes =
+			[
 				"int",
 				"uint",
 				"long",
@@ -397,17 +407,13 @@ public class NumericParameter : X1010_IncompatibleValueType
 				"float",
 				"double",
 				"decimal",
-			};
+			];
 
-			public static IEnumerable<object[]> NumericValuesAndNumericTypes =>
-				from value in NumericValues()
-				from type in NumericTypes
-				select new[] { value[0], type[0] };
+			public static MatrixTheoryData<string, string> NumericValuesAndNumericTypes =
+				new(NumericValues, NumericTypes);
 
-			public static IEnumerable<object[]> BoolValuesAndNumericTypes =>
-				from value in BoolValues
-				from type in NumericTypes
-				select new[] { value[0], type[0] };
+			public static MatrixTheoryData<string, string> BoolValuesAndNumericTypes =
+				new(BoolValues, NumericTypes);
 
 			[Theory]
 			[MemberData(nameof(NumericValuesAndNumericTypes))]
@@ -415,12 +421,13 @@ public async Task CompatibleNumericValue_NonNullableType(
 				string value,
 				string type)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod({type} a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod({1} a) {{ }}
+					}}
+					""", value, type);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -431,12 +438,13 @@ public async Task CompatibleNumericValue_NullableType(
 				string value,
 				string type)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod({type}? a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod({1}? a) {{ }}
+					}}
+					""", value, type);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -447,17 +455,14 @@ public async Task BooleanValue_NumericType(
 				string value,
 				string type)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod({type} a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", type);
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod({1} a) {{ }}
+					}}
+					""", value, type);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", type);
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -466,12 +471,13 @@ public void TestMethod({type} a) {{ }}
 			[MemberData(nameof(NumericTypes))]
 			public async Task CharValue_NumericType(string type)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData('a')]
-    public void TestMethod({type} a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData('a')]
+					    public void TestMethod({0} a) {{ }}
+					}}
+					""", type);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -480,17 +486,14 @@ public void TestMethod({type} a) {{ }}
 			[MemberData(nameof(NumericTypes))]
 			public async Task EnumValue_NumericType(string type)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(System.StringComparison.InvariantCulture)]
-    public void TestMethod({type} a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 63)
-						.WithArguments("a", type);
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:System.StringComparison.InvariantCulture|}})]
+					    public void TestMethod({0} a) {{ }}
+					}}
+					""", type);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", type);
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -502,12 +505,13 @@ public class BooleanParameter : X1010_IncompatibleValueType
 			[MemberData(nameof(BoolValues))]
 			public async Task FromBooleanValue_ToNonNullable(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(bool a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(bool a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -516,12 +520,13 @@ public void TestMethod(bool a) {{ }}
 			[MemberData(nameof(BoolValues))]
 			public async Task FromBooleanValue_ToNullable(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(bool? a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(bool? a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -534,16 +539,17 @@ public void TestMethod(bool? a) {{ }}
 			[InlineData("typeof(string)")]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(bool a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(bool a) {{ }}
+					}}
+					""", value);
 				var expected =
 					Verify
 						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
+						.WithLocation(0)
 						.WithArguments("a", "bool");
 
 				await Verify.VerifyAnalyzer(source, expected);
@@ -557,12 +563,13 @@ public class CharParameter : X1010_IncompatibleValueType
 			[MemberData(nameof(IntegerValues))]
 			public async Task FromCharOrIntegerValue_ToNonNullable(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(char a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(char a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -572,12 +579,13 @@ public void TestMethod(char a) {{ }}
 			[MemberData(nameof(IntegerValues))]
 			public async Task FromCharOrIntegerValue_ToNullable(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(char? a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(char? a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -590,17 +598,14 @@ public void TestMethod(char? a) {{ }}
 			[InlineData("typeof(string)")]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(char a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "char");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(char a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "char");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -611,12 +616,13 @@ public class EnumParameter : X1010_IncompatibleValueType
 			[Fact]
 			public async Task FromEnumValue_ToNonNullable()
 			{
-				var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(System.StringComparison.Ordinal)]
-    public void TestMethod(System.StringComparison a) { }
-}";
+				var source = /* lang=c#-test */ """
+					public class TestClass {
+					    [Xunit.Theory]
+					    [Xunit.InlineData(System.StringComparison.Ordinal)]
+					    public void TestMethod(System.StringComparison a) { }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -624,12 +630,13 @@ public void TestMethod(System.StringComparison a) { }
 			[Fact]
 			public async Task FromEnumValue_ToNullable()
 			{
-				var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(System.StringComparison.Ordinal)]
-    public void TestMethod(System.StringComparison? a) { }
-}";
+				var source = /* lang=c#-test */ """
+					public class TestClass {
+					    [Xunit.Theory]
+					    [Xunit.InlineData(System.StringComparison.Ordinal)]
+					    public void TestMethod(System.StringComparison? a) { }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -642,17 +649,14 @@ public void TestMethod(System.StringComparison? a) { }
 			[InlineData("typeof(string)")]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(System.StringComparison a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "System.StringComparison");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(System.StringComparison a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "System.StringComparison");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -665,12 +669,13 @@ public class TypeParameter : X1010_IncompatibleValueType
 			[InlineData("null")]
 			public async Task FromTypeValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(System.Type a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(System.Type a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -680,12 +685,13 @@ public void TestMethod(System.Type a) {{ }}
 			[InlineData("null")]
 			public async Task FromTypeValue_ToParams(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(params System.Type[] a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(params System.Type[] a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -698,18 +704,14 @@ public void TestMethod(params System.Type[] a) {{ }}
 			[InlineData("System.StringComparison.Ordinal")]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(System.Type a) {{ }}
-}}";
-
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "System.Type");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(System.Type a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "System.Type");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -722,17 +724,14 @@ public void TestMethod(System.Type a) {{ }}
 			[InlineData("System.StringComparison.Ordinal")]
 			public async Task FromIncompatibleValue_ToParams(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(params System.Type[] a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "System.Type");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(params System.Type[] a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "System.Type");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -745,12 +744,13 @@ public class StringParameter : X1010_IncompatibleValueType
 			[InlineData("null")]
 			public async Task FromStringValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(string a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(string a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -763,17 +763,14 @@ public void TestMethod(string a) {{ }}
 			[InlineData("typeof(string)")]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(string a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "string");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(string a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "string");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -787,12 +784,13 @@ public class InterfaceParameter : X1010_IncompatibleValueType
 			[InlineData("null")]
 			public async Task FromTypeImplementingInterface(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(System.IFormattable a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(System.IFormattable a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -806,17 +804,14 @@ public void TestMethod(System.IFormattable a) {{ }}
 			[MemberData(nameof(BoolValues))]
 			public async Task FromIncompatibleValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(System.IFormattable a) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "System.IFormattable");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(System.IFormattable a) {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "System.IFormattable");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -834,12 +829,13 @@ public class ObjectParameter : X1010_IncompatibleValueType
 			[InlineData("typeof(string)")]
 			public async Task FromAnyValue(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(object a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(object a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -854,12 +850,13 @@ public void TestMethod(object a) {{ }}
 			[InlineData("typeof(string)")]
 			public async Task FromAnyValue_ToParams(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod(params object[] a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod(params object[] a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -877,12 +874,13 @@ public class GenericParameter : X1010_IncompatibleValueType
 			[InlineData("typeof(string)")]
 			public async Task FromAnyValue_NoConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod<T>(T a) {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -894,12 +892,13 @@ public void TestMethod<T>(T a) {{ }}
 			[InlineData("'a'")]
 			public async Task FromValueTypeValue_WithStructConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: struct {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod<T>(T a) where T: struct {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -909,17 +908,14 @@ public void TestMethod<T>(T a) where T: struct {{ }}
 			[InlineData("typeof(string)")]
 			public async Task FromReferenceTypeValue_WithStructConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: struct {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "T");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod<T>(T a) where T: struct {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "T");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -930,12 +926,13 @@ public void TestMethod<T>(T a) where T: struct {{ }}
 			[InlineData("null")]
 			public async Task FromReferenceTypeValue_WithClassConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: class {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod<T>(T a) where T: class {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -947,17 +944,14 @@ public void TestMethod<T>(T a) where T: class {{ }}
 			[InlineData("'a'")]
 			public async Task FromValueTypeValue_WithClassConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: class {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "T");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod<T>(T a) where T: class {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "T");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -968,12 +962,13 @@ public void TestMethod<T>(T a) where T: class {{ }}
 			[MemberData(nameof(NumericValues))]
 			public async Task FromCompatibleValue_WithTypeConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable {{ }}
-}}";
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({0})]
+					    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable {{ }}
+					}}
+					""", value);
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -987,17 +982,15 @@ public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable
 			[MemberData(nameof(BoolValues))]
 			public async Task FromIncompatibleValue_WithTypeConstraint(string value)
 			{
-				var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({value})]
-    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 23, 4, 23 + value.Length)
-						.WithArguments("a", "T");
+				var source = string.Format(/* lang=c#-test */ """
+
+					public class TestClass {{
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable {{ }}
+					}}
+					""", value);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "T");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -1005,17 +998,14 @@ public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable
 			[Fact]
 			public async Task FromIncompatibleArray()
 			{
-				var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new int[] { 1, 2, 3 })]
-    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable { }
-}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(4, 35, 4, 36)
-						.WithArguments("a", "T");
+				var source =/* lang=c#-test */ """
+					public class TestClass {
+					    [Xunit.Theory]
+					    [Xunit.InlineData(new int[] { {|#0:1|}, 2, 3 })]
+					    public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable { }
+					}
+					""";
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("a", "T");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -1023,12 +1013,13 @@ public void TestMethod<T>(T a) where T: System.IConvertible, System.IFormattable
 			[Fact]
 			public async Task FromCompatibleArray()
 			{
-				var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new int[] { 1, 2, 3 })]
-    public void TestMethod<T>(T[] a) { }
-}";
+				var source = /* lang=c#-test */ """
+					public class TestClass {
+					    [Xunit.Theory]
+					    [Xunit.InlineData(new int[] { 1, 2, 3 })]
+					    public void TestMethod<T>(T[] a) { }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -1036,20 +1027,17 @@ public void TestMethod<T>(T[] a) { }
 
 		public class DateTimeLikeParameter : X1010_IncompatibleValueType
 		{
-			public static readonly TheoryData<string> ValidDateTimeStrings = new()
-			{
+			public static readonly TheoryData<string> ValidDateTimeStrings =
+			[
 				"\"\"",
 				"\"2018-01-02\"",
 				"\"2018-01-02 12:34\"",
 				"\"obviously-rubbish-datetime-value\"",
 				"MyConstString"
-			};
+			];
 
-			public static IEnumerable<object[]> ValueTypedArgumentsCombinedWithDateTimeLikeTypes =>
-				ValueTypedValues().SelectMany(v =>
-					new string[] { "System.DateTime", "System.DateTimeOffset" }
-						.Select(dateTimeLikeType => new[] { v[0], dateTimeLikeType })
-				);
+			public static MatrixTheoryData<string, string> ValueTypedArgumentsCombinedWithDateTimeLikeTypes =
+				new(ValueTypedValues, ["System.DateTime", "System.DateTimeOffset"]);
 
 			[Theory]
 			[MemberData(nameof(ValueTypedArgumentsCombinedWithDateTimeLikeTypes))]
@@ -1059,20 +1047,16 @@ public async Task NonStringValue(
 				string data,
 				string parameterType)
 			{
-				var source = $@"
-public class TestClass
-{{
-    const int MyConstInt = 1;
-
-    [Xunit.Theory]
-    [Xunit.InlineData({data})]
-    public void TestMethod({parameterType} parameter) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(7, 23, 7, 23 + data.Length)
-						.WithArguments("parameter", parameterType);
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    const int MyConstInt = 1;
+
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod({1} parameter) {{ }}
+					}}
+					""", data, parameterType);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("parameter", parameterType);
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -1099,59 +1083,51 @@ public async Task StringValue_ToDateTimeOffset(string data)
 			[MemberData(nameof(ValidDateTimeStrings))]
 			public async Task StringValue_ToDateTimeOffset_Pre240(string data)
 			{
-				var source = CreateSourceWithStringConst(data, "System.DateTimeOffset");
-				var expected =
-					Verify_v2_Pre240
-						.Diagnostic("xUnit1010")
-						.WithSpan(7, 23, 7, 23 + data.Length)
-						.WithArguments("parameter", "System.DateTimeOffset");
+				var source = CreateSourceWithStringConst("{|#0:" + data + "|}", "System.DateTimeOffset");
+				var expected = Verify_v2_Pre240.Diagnostic("xUnit1010").WithLocation(0).WithArguments("parameter", "System.DateTimeOffset");
 
 				await Verify_v2_Pre240.VerifyAnalyzer(source, expected);
 			}
 
 			static string CreateSourceWithStringConst(
 				string data,
-				string parameterType) => $@"
-public class TestClass
-{{
-    const string MyConstString = ""some string"";
-
-    [Xunit.Theory]
-    [Xunit.InlineData({data})]
-    public void TestMethod({parameterType} parameter) {{ }}
-}}";
+				string parameterType) => string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    const string MyConstString = "some string";
+
+				    [Xunit.Theory]
+				    [Xunit.InlineData({0})]
+				    public void TestMethod({1} parameter) {{ }}
+				}}
+				""", data, parameterType);
 		}
 
 		public class GuidParameter : X1010_IncompatibleValueType
 		{
-			public static TheoryData<string> ValidGuidStrings = new()
-			{
+			public static TheoryData<string> ValidGuidStrings =
+			[
 				"\"\"",
 				"\"{5B21E154-15EB-4B1E-BC30-127E8A41ECA1}\"",
 				"\"4EBCD32C-A2B8-4600-9E72-3873347E285C\"",
 				"\"39A3B4C85FEF43A988EB4BB4AC4D4103\"",
 				"\"obviously-rubbish-guid-value\""
-			};
+			];
 
 			[Theory]
 			[MemberData(nameof(ValueTypedValues))]
 			[InlineData("MyConstInt")]
 			public async Task NonStringValue(string data)
 			{
-				var source = $@"
-public class TestClass
-{{
-    private const int MyConstInt = 1;
-
-    [Xunit.Theory]
-    [Xunit.InlineData({data})]
-    public void TestMethod(System.Guid parameter) {{ }}
-}}";
-				var expected =
-					Verify
-						.Diagnostic("xUnit1010")
-						.WithSpan(7, 23, 7, 23 + data.Length)
-						.WithArguments("parameter", "System.Guid");
+				var source = string.Format(/* lang=c#-test */ """
+					public class TestClass {{
+					    private const int MyConstInt = 1;
+
+					    [Xunit.Theory]
+					    [Xunit.InlineData({{|#0:{0}|}})]
+					    public void TestMethod(System.Guid parameter) {{ }}
+					}}
+					""", data);
+				var expected = Verify.Diagnostic("xUnit1010").WithLocation(0).WithArguments("parameter", "System.Guid");
 
 				await Verify.VerifyAnalyzer(source, expected);
 			}
@@ -1169,23 +1145,19 @@ public async Task StringValue(string inlineData)
 			[MemberData(nameof(ValidGuidStrings))]
 			public async Task StringValue_Pre240(string data)
 			{
-				var source = CreateSource(data);
-				var expected =
-					Verify_v2_Pre240
-						.Diagnostic("xUnit1010")
-						.WithSpan(5, 23, 5, 23 + data.Length)
-						.WithArguments("parameter", "System.Guid");
+				var source = CreateSource("{|#0:" + data + "|}");
+				var expected = Verify_v2_Pre240.Diagnostic("xUnit1010").WithLocation(0).WithArguments("parameter", "System.Guid");
 
 				await Verify_v2_Pre240.VerifyAnalyzer(source, expected);
 			}
 
-			static string CreateSource(string data) => $@"
-public class TestClass
-{{
-    [Xunit.Theory]
-    [Xunit.InlineData({data})]
-    public void TestMethod(System.Guid parameter) {{ }}
-}}";
+			static string CreateSource(string data) => string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData({0})]
+				    public void TestMethod(System.Guid parameter) {{ }}
+				}}
+				""", data);
 		}
 
 		public class UserDefinedConversionOperators : X1010_IncompatibleValueType
@@ -1193,20 +1165,21 @@ public class UserDefinedConversionOperators : X1010_IncompatibleValueType
 			[Fact]
 			public async Task SupportsImplicitConversion()
 			{
-				var source = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(""abc"")]
-    public void ParameterDeclaredImplicitConversion(Implicit i) => Assert.Equal(""abc"", i.Value);
-
-    public class Implicit {
-        public string Value { get; set; }
-        public static implicit operator Implicit(string value) => new Implicit() { Value = value };
-        public static implicit operator string(Implicit i) => i.Value;
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using Xunit;
+
+					public class TestClass {
+					    [Theory]
+					    [InlineData("abc")]
+					    public void ParameterDeclaredImplicitConversion(Implicit i) => Assert.Equal("abc", i.Value);
+
+					    public class Implicit {
+					        public string Value { get; set; }
+					        public static implicit operator Implicit(string value) => new Implicit() { Value = value };
+					        public static implicit operator string(Implicit i) => i.Value;
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -1214,20 +1187,21 @@ public class Implicit {
 			[Fact]
 			public async Task SupportsExplicitConversion()
 			{
-				var source = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(""abc"")]
-    public void ParameterDeclaredExplicitConversion(Explicit i) => Assert.Equal(""abc"", i.Value);
-
-    public class Explicit {
-        public string Value { get; set; }
-        public static explicit operator Explicit(string value) => new Explicit() { Value = value };
-        public static explicit operator string(Explicit i) => i.Value;
-    }
-}";
+				var source = /* lang=c#-test */ """
+					using Xunit;
+
+					public class TestClass {
+					    [Theory]
+					    [InlineData("abc")]
+					    public void ParameterDeclaredExplicitConversion(Explicit i) => Assert.Equal("abc", i.Value);
+
+					    public class Explicit {
+					        public string Value { get; set; }
+					        public static explicit operator Explicit(string value) => new Explicit() { Value = value };
+					        public static explicit operator string(Explicit i) => i.Value;
+					    }
+					}
+					""";
 
 				await Verify.VerifyAnalyzer(source);
 			}
@@ -1235,20 +1209,20 @@ public class Explicit {
 
 		// Note: decimal literal 42M is not valid as an attribute argument
 
-		public static TheoryData<string> BoolValues = new()
-		{
+		public static TheoryData<string> BoolValues =
+		[
 			"true",
 			"false"
-		};
+		];
 
-		public static TheoryData<string> FloatingPointValues = new()
-		{
+		public static TheoryData<string> FloatingPointValues =
+		[
 			"42f",
 			"42d"
-		};
+		];
 
-		public static TheoryData<string> IntegerValues = new()
-		{
+		public static TheoryData<string> IntegerValues =
+		[
 			"42",
 			"42L",
 			"42u",
@@ -1257,25 +1231,13 @@ public class Explicit {
 			"(byte)42",
 			"(ushort)42",
 			"(sbyte)42"
-		};
-
-		public static IEnumerable<object[]> NumericValues()
-		{
-			foreach (var integerValue in IntegerValues)
-				yield return integerValue;
-			foreach (var floatingPointValue in FloatingPointValues)
-				yield return floatingPointValue;
-		}
+		];
 
-		public static IEnumerable<object[]> ValueTypedValues()
-		{
-			foreach (var numericValue in NumericValues())
-				yield return numericValue;
-			foreach (var boolValue in BoolValues)
-				yield return boolValue;
+		public static TheoryData<string> NumericValues =
+			new(((IEnumerable<string>)IntegerValues).Concat(FloatingPointValues));
 
-			yield return new[] { "typeof(int)" };
-		}
+		public static TheoryData<string> ValueTypedValues =
+			new(((IEnumerable<string>)IntegerValues).Concat(FloatingPointValues).Concat(BoolValues).Append("typeof(int)"));
 	}
 
 	public class X1011_ExtraValue
@@ -1283,12 +1245,13 @@ public class X1011_ExtraValue
 		[Fact]
 		public async Task IgnoresFact()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.InlineData(1, 2, ""abc"")]
-    public void TestMethod(int a) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    [Xunit.InlineData(1, 2, "abc")]
+				    public void TestMethod(int a) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1296,25 +1259,18 @@ public void TestMethod(int a) { }
 		[Fact]
 		public async Task ExtraArguments()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(1, 2, ""abc"")]
-    public void TestMethod(int a) { }
-}";
-			DiagnosticResult[] expected =
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, {|#0:2|}, {|#1:"abc"|})]
+				    public void TestMethod(int a) { }
+				}
+				""";
+			var expected = new[]
 			{
-					Verify
-						.Diagnostic("xUnit1011")
-						.WithSpan(4, 26, 4, 27)
-						.WithSeverity(DiagnosticSeverity.Error)
-						.WithArguments("2"),
-					Verify
-						.Diagnostic("xUnit1011")
-						.WithSpan(4, 29, 4, 34)
-						.WithSeverity(DiagnosticSeverity.Error)
-						.WithArguments("\"abc\""),
-				};
+				Verify.Diagnostic("xUnit1011").WithLocation(0).WithArguments("2"),
+				Verify.Diagnostic("xUnit1011").WithLocation(1).WithArguments("\"abc\""),
+			};
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1325,12 +1281,13 @@ public class X1012_NullShouldNotBeUsedForIncompatibleParameter
 		[Fact]
 		public async Task IgnoresFact()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.InlineData(null)]
-    public void TestMethod(int a) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    [Xunit.InlineData(null)]
+				    public void TestMethod(int a) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1340,18 +1297,14 @@ public void TestMethod(int a) { }
 		[InlineData("params int[]")]
 		public async Task SingleNullValue(string type)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(null)]
-    public void TestMethod({type} a) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1012")
-					.WithSpan(4, 23, 4, 27)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("a", "int");
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData({{|#0:null|}})]
+				    public void TestMethod({0} a) {{ }}
+				}}
+				""", type);
+			var expected = Verify.Diagnostic("xUnit1012").WithLocation(0).WithArguments("a", "int");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1360,25 +1313,18 @@ public void TestMethod({type} a) {{ }}
 		[MemberData(nameof(ValueTypes))]
 		public async Task NonNullableValueTypes(string type)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null, null)]
-    public void TestMethod(int a, {type} b, params {type}[] c) {{ }}
-}}";
-			DiagnosticResult[] expected =
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, {{|#0:null|}}, {{|#1:null|}})]
+				    public void TestMethod(int a, {0} b, params {0}[] c) {{ }}
+				}}
+				""", type);
+			var expected = new[]
 			{
-					Verify
-						.Diagnostic("xUnit1012")
-						.WithSpan(4, 26, 4, 30)
-						.WithSeverity(DiagnosticSeverity.Warning)
-						.WithArguments("b", type),
-					Verify
-						.Diagnostic("xUnit1012")
-						.WithSpan(4, 32, 4, 36)
-						.WithSeverity(DiagnosticSeverity.Warning)
-						.WithArguments("c", type),
-				};
+				Verify.Diagnostic("xUnit1012").WithLocation(0).WithArguments("b", type),
+				Verify.Diagnostic("xUnit1012").WithLocation(1).WithArguments("c", type),
+			};
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1387,12 +1333,13 @@ public void TestMethod(int a, {type} b, params {type}[] c) {{ }}
 		[MemberData(nameof(ValueTypes))]
 		public async Task NullableValueTypes(string type)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null)]
-    public void TestMethod(int a, {type}? b) {{ }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, null)]
+				    public void TestMethod(int a, {0}? b) {{ }}
+				}}
+				""", type);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1403,12 +1350,13 @@ public void TestMethod(int a, {type}? b) {{ }}
 		[InlineData("System.Exception")]
 		public async Task ReferenceTypes(string type)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null)]
-    public void TestMethod(int a, {type} b) {{ }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, null)]
+				    public void TestMethod(int a, {0} b) {{ }}
+				}}
+				""", type);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1419,23 +1367,16 @@ public void TestMethod(int a, {type} b) {{ }}
 		[InlineData("System.Exception")]
 		public async Task NonNullableReferenceTypes(string type)
 		{
-			var source = $@"
-#nullable enable
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null)]
-    public void TestMethod(int a, {type} b) {{ }}
-#nullable restore
-}}";
-
-			DiagnosticResult[] expected =
-			{
-				Verify
-					.Diagnostic("xUnit1012")
-					.WithSpan(5, 26, 5, 30)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("b", type)
-			};
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
+
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, {{|#0:null|}})]
+				    public void TestMethod(int a, {0} b) {{ }}
+				}}
+				""", type);
+			var expected = Verify.Diagnostic("xUnit1012").WithLocation(0).WithArguments("b", type);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
@@ -1446,14 +1387,15 @@ public void TestMethod(int a, {type} b) {{ }}
 		[InlineData("System.Exception")]
 		public async Task NullableReferenceTypes(string type)
 		{
-			var source = $@"
-#nullable enable
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null)]
-    public void TestMethod(int a, {type}? b) {{ }}
-#nullable restore
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
+
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, null)]
+				    public void TestMethod(int a, {0}? b) {{ }}
+				}}
+				""", type);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -1461,16 +1403,19 @@ public void TestMethod(int a, {type}? b) {{ }}
 		[Theory]
 		[InlineData("1", "object")]
 		[InlineData("\"bob\"", "string")]
-		public async Task NullableParamsReferenceTypes(string param, string type)
+		public async Task NullableParamsReferenceTypes(
+			string param,
+			string type)
 		{
-			var source = $@"
-#nullable enable
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, {param}, null, null)]
-    public void TestMethod(int a, params {type}?[] b) {{ }}
-#nullable restore
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
+
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, {0}, null, null)]
+				    public void TestMethod(int a, params {1}?[] b) {{ }}
+				}}
+				""", param, type);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -1478,36 +1423,36 @@ public void TestMethod(int a, params {type}?[] b) {{ }}
 		[Theory]
 		[InlineData("1", "object")]
 		[InlineData("\"bob\"", "string")]
-		public async Task NonNullableParamsReferenceTypes(string param, string type)
+		public async Task NonNullableParamsReferenceTypes(
+			string param,
+			string type)
 		{
-			var source = $@"
-#nullable enable
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, {param}, null, null)]
-    public void TestMethod(int a, params {type}[] b) {{ }}
-#nullable restore
-}}";
-
-			DiagnosticResult[] expected =
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
+
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, {0}, {{|#0:null|}}, {{|#1:null|}})]
+				    public void TestMethod(int a, params {1}[] b) {{ }}
+				}}
+				""", param, type);
+			var expected = new[]
 			{
 				Verify
 					.Diagnostic("xUnit1012")
-					.WithSpan(5, 28 + param.Length, 5, 32 + param.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
+					.WithLocation(0)
 					.WithArguments("b", type),
 				Verify
 					.Diagnostic("xUnit1012")
-					.WithSpan(5, 34 + param.Length, 5, 38 + param.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
+					.WithLocation(1)
 					.WithArguments("b", type),
 			};
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
 
-		public static TheoryData<string> ValueTypes = new()
-		{
+		public static TheoryData<string> ValueTypes =
+		[
 			"bool",
 			"int",
 			"byte",
@@ -1523,7 +1468,7 @@ public void TestMethod(int a, params {type}[] b) {{ }}
 			"sbyte",
 			"System.StringComparison",
 			"System.Guid",
-		};
+		];
 	}
 
 	internal class Analyzer_v2_Pre240 : InlineDataMustMatchTheoryParameters
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataShouldBeUniqueWithinTheoryTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataShouldBeUniqueWithinTheoryTests.cs
index bc5e7f40..b826a78b 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataShouldBeUniqueWithinTheoryTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataShouldBeUniqueWithinTheoryTests.cs
@@ -1,5 +1,5 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.InlineDataShouldBeUniqueWithinTheory>;
 
@@ -8,13 +8,14 @@ public abstract class InlineDataShouldBeUniqueWithinTheoryTests
 	public class ForNonRelatedToInlineDataMethod : InlineDataShouldBeUniqueWithinTheoryTests
 	{
 		[Fact]
-		public async Task DoesNotFindError_WhenNoDataAttributes()
+		public async Task WithNoDataAttributes_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -22,15 +23,16 @@ public void TestMethod() { }
 		[Theory]
 		[InlineData("MemberData(\"\")")]
 		[InlineData("ClassData(typeof(string))")]
-		public async Task DoesNotFindError_WhenDataAttributesOtherThanInline(
+		public async Task WithDataAttributesOtherThanInline_DoesNotTrigger(
 			string dataAttribute)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.{0}]
+				    public void TestMethod() {{ }}
+				}}
+				""", dataAttribute);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -39,147 +41,142 @@ public void TestMethod() {{ }}
 	public class ForUniqueInlineDataMethod : InlineDataShouldBeUniqueWithinTheoryTests
 	{
 		[Fact]
-		public async Task DoesNotFindError_WhenNonTheorySingleInlineData()
+		public async Task NonTheory_SingleInlineData_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.InlineData]
-    public void TestMethod(int x) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    [Xunit.InlineData]
+				    public void TestMethod(int x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenNonTheoryDoubledInlineData()
+		public async Task NonTheory_DoubledInlineData_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.InlineData]
-    [Xunit.InlineData]
-    public void TestMethod(int x) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    [Xunit.InlineData]
+				    [Xunit.InlineData]
+				    public void TestMethod(int x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenSingleInlineDataContainingValue()
+		public async Task SingleInlineData_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    public void TestMethod(int x) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    public void TestMethod(int x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenInlineDataAttributesHaveDifferentParameterValues()
+		public async Task MultipleInlineData_DifferentValues_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(20)]
-    public void TestMethod(int x) { }
-}";
-
-			await Verify.VerifyAnalyzer(source);
-		}
-
-		[Fact]
-		public async Task DoesNotFindError_WhenInlineDataAttributesDifferAtLastParameterValue()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10, ""foo"")]
-    [Xunit.InlineData(10, ""bar"")]
-    public void TestMethod(int x, string y) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    [Xunit.InlineData(20)]
+				    public void TestMethod(int x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("new object[] { 1, 3 }")]
-		[InlineData("data: new object[] { 1, 3 }")]
-		[InlineData("new object[] { }")]
-		[InlineData("data: new object[] { 1 }")]
-		public async Task DoesNotFindError_WhenUniquenessProvidedWithParamsInitializerValues(string data)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(1, 2)]
-    [Xunit.InlineData({data})]
-    public void TestMethod(params int[] args) {{ }}
-}}";
+		[InlineData(/* lang=c#-test */ "new object[] { 1, 3 }")]
+		[InlineData(/* lang=c#-test */ "data: new object[] { 1, 3 }")]
+		[InlineData(/* lang=c#-test */ "new object[] { }")]
+		[InlineData(/* lang=c#-test */ "data: new object[] { 1 }")]
+		public async Task UniqueValues_WithParamsInitializerValues_DoesNotTrigger(string data)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, 2)]
+				    [Xunit.InlineData({0})]
+				    public void TestMethod(params int[] args) {{ }}
+				}}
+				""", data);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenUniquenessProvidedWithOverridingDefaultValues()
+		public async Task UniqueValues_WithOverridingDefaultValues_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(1)]
-    [Xunit.InlineData(1, ""non-default-val"")]
-    public void TestMethod(int x, string a = ""default-val"") { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1)]
+				    [Xunit.InlineData(1, "non-default-val")]
+				    public void TestMethod(int x, string a = "default-val") { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenNullAndEmptyInlineDataAttributes()
+		public async Task NullAndEmpty_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(null)]
-    [Xunit.InlineData]
-    public void TestMethod(string s) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(null)]
+				    [Xunit.InlineData]
+				    public void TestMethod(string s) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenNewArrayAndNullDataAttributes()
+		public async Task NullAndArray_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass{
-    [Xunit.Theory]
-    [Xunit.InlineData(new[] { 0 })]
-    [Xunit.InlineData(null)]
-    public void TestMethod(int[] arr) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new[] { 0 })]
+				    [Xunit.InlineData(null)]
+				    public void TestMethod(int[] arr) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task DoesNotFindError_WhenFirstArrayIsEqualAndEmptyArraysAreUsed()
+		public async Task ArrayOrderVariance_DoesNotTrigger()
 		{
 			// Specially crafted InlineData values that will cause the InlineDataUniquenessComparer
 			// to return same hashcodes, because GetFlattenedArgumentPrimitives ignores empty arrays.
 			// This will trigger the actual bug, where the first parameter object array being equal
 			// would cause the other parameters to not be evaluated for equality at all.
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new int[] { 1 }, new int[0], new int[] { 1 })]
-    [Xunit.InlineData(new int[] { 1 }, new int[] { 1 }, new int[0])]
-    public static void Test(int[] x, int[] y, int[] z) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new int[] { 1 }, new int[0], new int[] { 1 })]
+				    [Xunit.InlineData(new int[] { 1 }, new int[] { 1 }, new int[0])]
+				    public static void Test(int[] x, int[] y, int[] z) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -188,254 +185,205 @@ public static void Test(int[] x, int[] y, int[] z) { }
 	public class ForDuplicatedInlineDataMethod : InlineDataShouldBeUniqueWithinTheoryTests
 	{
 		[Fact]
-		public async Task FindsError_WhenEmptyInlineDataRepeatedTwice()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData]
-    [Xunit.InlineData]
-    public void TestMethod(int x) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 22)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubleEmptyInlineData_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData]
+				    [{|#0:Xunit.InlineData|}]
+				    public void TestMethod(int x) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenNullInlineDataRepeatedTwice()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(null)]
-    [Xunit.InlineData(null)]
-    public void TestMethod(string x) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 28)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubleNullInlineData_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(null)]
+				    [{|#0:Xunit.InlineData(null)|}]
+				    public void TestMethod(string x) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenInlineDataAttributesHaveExactlySameDeclarations()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(10)]
-    public void TestMethod(int x) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubleValues_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    [{|#0:Xunit.InlineData(10)|}]
+				    public void TestMethod(int x) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenInlineDataAttributesHaveSameCompilationTimeEvaluation()
+		public async Task ValueFromConstant_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    private const int X = 10;
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(X)]
-    public void TestMethod(int x) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(6, 6, 6, 25)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    private const int X = 10;
+
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    [{|#0:Xunit.InlineData(X)|}]
+				    public void TestMethod(int x) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
-		[InlineData("new object[] { 10, 20 }")]
-		[InlineData("data: new object[] { 10, 20 }")]
-		public async Task FindsError_WhenInlineDataHaveSameParameterValuesButDeclaredArrayCollectionOfArguments(string data)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(10, 20)]
-    [Xunit.InlineData({data})]
-    public void TestMethod(int x, int y) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 24 + data.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		[InlineData(/* lang=c#-test */ "new object[] { 10, 20 }")]
+		[InlineData(/* lang=c#-test */ "data: new object[] { 10, 20 }")]
+		public async Task TwoParams_RawValuesVsArgumentArray_Triggers(string data)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10, 20)]
+				    [{{|#0:Xunit.InlineData({0})|}}]
+				    public void TestMethod(int x, int y) {{ }}
+				}}
+				""", data);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
-		[InlineData("new object[] { 10, 20 }")]
-		[InlineData("data: new object[] { 10, 20 }")]
-		public async Task FindsError_WhenTestMethodIsDefinedWithParamsArrayOfArguments(string data)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData(10, 20)]
-    [Xunit.InlineData({data})]
-    public void TestMethod(params int[] args) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 24 + data.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		[InlineData(/* lang=c#-test */ "new object[] { 10, 20 }")]
+		[InlineData(/* lang=c#-test */ "data: new object[] { 10, 20 }")]
+		public async Task ParamsArray_RawValuesVsArgumentArray_Triggers(string data)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10, 20)]
+				    [{{|#0:Xunit.InlineData({0})|}}]
+				    public void TestMethod(params int[] args) {{ }}
+				}}
+				""", data);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenBothInlineDataHaveObjectArrayCollectionOfArguments()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new object[] { 10, 20 })]
-    [Xunit.InlineData(new object[] { 10, 20 })]
-    public void TestMethod(int x, int y) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 47)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubledArgumentArrays_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new object[] { 10, 20 })]
+				    [{|#0:Xunit.InlineData(new object[] { 10, 20 })|}]
+				    public void TestMethod(int x, int y) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenArgumentsAreArrayOfValues()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})]
-    [Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})]
-    public void TestMethod(object x, object y) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 80)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubledComplexValuesForObject_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})]
+				    [{|#0:Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})|}]
+				    public void TestMethod(object x, object y) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenArgumentsAreArrayOfValuesAndTestMethodOffersDefaultParameterValues()
-		{
-			var source = @"
-public class TestClass {
-   [Xunit.Theory]
-   [Xunit.InlineData(10, new object[] { new object[] {20}, 30}, 40)]
-   [Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})]
-   [Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}, 50})]
-   [Xunit.InlineData(new object[] {10, new object[] { new object[] {90}, 30}, 40})]
-   public void TestMethod(object x, object y, int z = 40) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 5, 5, 79)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DoubledComplexValues_RawValuesVsArgumentArray_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				   [Xunit.Theory]
+				   [Xunit.InlineData(10, new object[] { new object[] {20}, 30}, 40)]
+				   [{|#0:Xunit.InlineData(new object[] {10, new object[] { new object[] {20}, 30}})|}]
+				   public void TestMethod(object x, object y, int z = 40) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		// The value 1 doesn't seem to trigger bugs related to comparing boxed values, but 2 does
-		public static TheoryData<int> DefaultValueData = new() { 1, 2 };
+		public static TheoryData<int> DefaultValueData = [1, 2];
 
 		[Theory]
 		[MemberData(nameof(DefaultValueData))]
-		public async Task FindsError_WhenFirstDuplicatedByDefaultValueOfParameter_DefaultInlineDataFirst(int defaultValue)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData]
-    [Xunit.InlineData({defaultValue})]
-    public void TestMethod(int y = {defaultValue}) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 25)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DefaultValueVsExplicitValue_Triggers(int defaultValue)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData]
+				    [{{|#0:Xunit.InlineData({0})|}}]
+				    public void TestMethod(int y = {0}) {{ }}
+				}}
+				""", defaultValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(DefaultValueData))]
-		public async Task FindsError_WhenSecondDuplicatedByDefaultValueOfParameter(int defaultValue)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({defaultValue})]
-    [Xunit.InlineData]
-    public void TestMethod(int y = {defaultValue}) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 22)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task ExplicitValueVsDefaultValue_Triggers(int defaultValue)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData({0})]
+				    [{{|#0:Xunit.InlineData|}}]
+				    public void TestMethod(int y = {0}) {{ }}
+				}}
+				""", defaultValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(DefaultValueData))]
-		public async Task FindsError_WhenTwoDuplicatedByDefaultValueOfParameter(int defaultValue)
-		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData]
-    [Xunit.InlineData]
-    public void TestMethod(int y = {defaultValue}) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 22)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task DefaultValueVsDefaultValue_Triggers(int defaultValue)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData]
+				    [{{|#0:Xunit.InlineData|}}]
+				    public void TestMethod(int y = {0}) {{ }}
+				}}
+				""", defaultValue);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -445,71 +393,59 @@ public void TestMethod(int y = {defaultValue}) {{ }}
 		[InlineData("null", "")]
 		[InlineData("", "null")]
 		[InlineData("", "")]
-		public async Task FindsError_WhenBothNullEntirelyOrBySingleDefaultParameterNullValue(
+		public async Task DefaultValueVsNull_Triggers(
 			string firstArg,
 			string secondArg)
 		{
-			var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.InlineData({firstArg})]
-    [Xunit.InlineData({secondArg})]
-    public void TestMethod(string x = null) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithLocation(5, 6)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [Xunit.Theory]
+				    [Xunit.InlineData({0})]
+				    [{{|#0:Xunit.InlineData({1})|}}]
+				    public void TestMethod(string x = null) {{ }}
+				}}
+				""", firstArg, secondArg);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenDuplicateContainsNulls()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(1, null)]
-    [Xunit.InlineData(new object[] {1, null})]
-    public void TestMethod(object x, object y) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 46)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+		public async Task Null_RawValuesVsExplicitArray_Triggers()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(1, null)]
+				    [{|#0:Xunit.InlineData(new object[] { 1, null })|}]
+				    public void TestMethod(object x, object y) { }
+				}
+				""";
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
 		[InlineData("", "")]
-		[InlineData("", ", null")]
-		[InlineData(", null", "")]
-		[InlineData(", null", ", null")]
-		public async Task FindsError_WhenDuplicateContainsDefaultOfStruct(
+		[InlineData("", ", default")]
+		[InlineData(", default", "")]
+		[InlineData(", default", ", default")]
+		public async Task DefaultOfStruct_Triggers(
 			string firstDefaultOverride,
 			string secondDefaultOverride)
 		{
-			var source = $@"
-public class TestClass {{
-   [Xunit.Theory]
-   [Xunit.InlineData(1 {firstDefaultOverride})]
-   [Xunit.InlineData(1 {secondDefaultOverride})]
-   public void TestMethod(int x, System.DateTime date = default(System.DateTime)) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 5, 5, 25 + secondDefaultOverride.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				   [Xunit.Theory]
+				   [Xunit.InlineData(1{0})]
+				   [{{|#0:Xunit.InlineData(1{1})|}}]
+				   public void TestMethod(int x, System.DateTime date = default) {{ }}
+				}}
+				""", firstDefaultOverride, secondDefaultOverride);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7_1, source, expected);
 		}
 
 		[Theory]
@@ -517,122 +453,61 @@ public class TestClass {{
 		[InlineData("", ", null")]
 		[InlineData(", null", "")]
 		[InlineData(", null", ", null")]
-		public async Task FindsError_WhenDuplicateContainsDefaultOfString(
+		public async Task DefaultOfString_Triggers(
 			string firstDefaultOverride,
 			string secondDefaultOverride)
 		{
-			var source = $@"
-public class TestClass {{
-   [Xunit.Theory]
-   [Xunit.InlineData(1 {firstDefaultOverride})]
-   [Xunit.InlineData(1 {secondDefaultOverride})]
-   public void TestMethod(int x, string y = null) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 5, 5, 25 + secondDefaultOverride.Length)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				   [Xunit.Theory]
+				   [Xunit.InlineData(1{0})]
+				   [{{|#0:Xunit.InlineData(1{1})|}}]
+				   public void TestMethod(int x, string y = null) {{ }}
+				}}
+				""", firstDefaultOverride, secondDefaultOverride);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsError_WhenInlineDataDuplicateAndOriginalAreItemsOfDistinctAttributesLists()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10, 20)]
-    [Xunit.InlineData(30, 40)]
-    [Xunit.InlineData(50, 60)]
-    [Xunit.InlineData(10, 20)]
-    public void TestMethod(int x, int y) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(7, 6, 7, 30)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
-
-			await Verify.VerifyAnalyzer(source, expected);
-		}
-
-		[Fact]
-		public async Task FindsErrorsTwiceOnCorrectLinesReferringToInitialOccurence_WhenThreeInlineDataAttributesConstituteDuplication()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(10)]
-    public void TestMethod(int x) { }
-}";
+		public async Task Tripled_TriggersTwice()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    [{|#0:Xunit.InlineData(10)|}]
+				    [{|#1:Xunit.InlineData(10)|}]
+				    public void TestMethod(int x) { }
+				}
+				""";
 			var expected = new[]
 			{
-				Verify
-					.Diagnostic()
-					.WithSpan(5, 6, 5, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass"),
-				Verify
-					.Diagnostic()
-					.WithSpan(6, 6, 6, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass"),
+				Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass"),
+				Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass"),
 			};
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Fact]
-		public async Task FindsErrorOnCorrectLineReferringToInitialOccurence_WhenDuplicateIsSeparatedByOtherNonDuplicateData()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(50)]
-    [Xunit.InlineData(10)]
-    public void TestMethod(int x) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(6, 6, 6, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass");
-
-			await Verify.VerifyAnalyzer(source, expected);
-		}
-
-		[Fact]
-		public async Task FindsErrorOnCorrectLineReferringToInitialOccurence_WhenTwoDuplicationEquivalenceSetsExistWithinTheory()
-		{
-			var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(20)]
-    [Xunit.InlineData(10)]
-    [Xunit.InlineData(20)]
-    public void TestMethod(int x) { }
-}";
+		public async Task DoubledTwice_TriggersTwice()
+		{
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Theory]
+				    [Xunit.InlineData(10)]
+				    [Xunit.InlineData(20)]
+				    [{|#0:Xunit.InlineData(10)|}]
+				    [{|#1:Xunit.InlineData(20)|}]
+				    public void TestMethod(int x) { }
+				}
+				""";
 			var expected = new[]
 			{
-				Verify
-					.Diagnostic()
-					.WithSpan(6, 6, 6, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass"),
-				Verify
-					.Diagnostic()
-					.WithSpan(7, 6, 7, 26)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("TestMethod", "TestClass"),
+				Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass"),
+				Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass"),
 			};
 
 			await Verify.VerifyAnalyzer(source, expected);
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/LocalFunctionsCannotBeTestFunctionsTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/LocalFunctionsCannotBeTestFunctionsTests.cs
index 5d72823e..10ef1fa2 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/LocalFunctionsCannotBeTestFunctionsTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/LocalFunctionsCannotBeTestFunctionsTests.cs
@@ -6,17 +6,15 @@
 public class LocalFunctionsCannotBeTestFunctionsTests
 {
 	[Fact]
-	public async Task DoesNotTriggerOnLocalFunctionWithoutAttributes()
+	public async Task NoTestAttribute_DoesNotTrigger()
 	{
-		var source = @"
-using Xunit;
-
-public class TestClass {
-    public void Method() {
-        void LocalFunction() {
-        }
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    public void Method() {
+			        void LocalFunction() { }
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(LanguageVersion.CSharp9, source);
 	}
@@ -27,27 +25,22 @@ void LocalFunction() {
 	[InlineData("InlineData(42)")]
 	[InlineData("MemberData(nameof(MyData))")]
 	[InlineData("ClassData(typeof(TestClass))")]
-	public async Task LocalFunctionsCannotHaveTestAttributes(string attribute)
+	public async Task TestAttribute_Triggers(string attribute)
 	{
-		var source = $@"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {{
-    public void Method() {{
-        [{attribute}]
-        void LocalFunction() {{
-        }}
-    }}
-
-    public static IEnumerable<object[]> MyData;
-}}";
-
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 10, 7, 10 + attribute.Length)
-				.WithArguments($"[{attribute}]");
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestClass {{
+			    public void Method() {{
+			        [{{|#0:{0}|}}]
+			        void LocalFunction() {{ }}
+			    }}
+
+			    public static IEnumerable<object[]> MyData;
+			}}
+			""", attribute);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"[{attribute}]");
 
 		await Verify.VerifyAnalyzer(LanguageVersion.CSharp9, source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/MemberDataShouldReferenceValidMemberTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/MemberDataShouldReferenceValidMemberTests.cs
index d92defb5..c0f3a075 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/MemberDataShouldReferenceValidMemberTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/MemberDataShouldReferenceValidMemberTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Testing;
 using Xunit;
@@ -9,95 +8,88 @@ public class MemberDataShouldReferenceValidMemberTests
 {
 	public class X1014_MemberDataShouldUseNameOfOperator
 	{
-		static readonly string sharedCode = @"
-using System.Collections.Generic;
-using Xunit;
+		static readonly string sharedCode = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-public partial class TestClass {
-    public static TheoryData<int> Data { get; set; }
-}
+			public partial class TestClass {
+			    public static TheoryData<int> Data { get; set; }
+			}
 
-public class OtherClass {
-    public static TheoryData<int> OtherData { get; set; }
-}";
+			public class OtherClass {
+			    public static TheoryData<int> OtherData { get; set; }
+			}
+			""";
 
 		[Fact]
 		public async Task NameofOnSameClass_DoesNotTrigger()
 		{
-			var source = @"
-public partial class TestClass {
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
+			var source = /* lang=c#-test */ """
+				public partial class TestClass {
+				    [Xunit.MemberData(nameof(Data))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(new[] { source, sharedCode });
+			await Verify.VerifyAnalyzer([source, sharedCode]);
 		}
 
 		[Fact]
 		public async Task NameofOnOtherClass_DoesNotTrigger()
 		{
-			var source = @"
-public partial class TestClass {
-    [Xunit.MemberData(nameof(OtherClass.OtherData), MemberType = typeof(OtherClass))]
-    public void TestMethod(int _) { }
-}";
+			var source = /* lang=c#-test */ """
+				public partial class TestClass {
+				    [Xunit.MemberData(nameof(OtherClass.OtherData), MemberType = typeof(OtherClass))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(new[] { source, sharedCode });
+			await Verify.VerifyAnalyzer([source, sharedCode]);
 		}
 
 		[Fact]
 		public async Task StringNameOnSameClass_Triggers()
 		{
-			var source = @"
-public partial class TestClass {
-    [Xunit.MemberData(""Data"")]
-    public void TestMethod(int _) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1014")
-					.WithSpan(3, 23, 3, 29)
-					.WithArguments("Data", "TestClass");
+			var source = /* lang=c#-test */ """
+				public partial class TestClass {
+				    [Xunit.MemberData({|#0:"Data"|})]
+				    public void TestMethod(int _) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1014").WithLocation(0).WithArguments("Data", "TestClass");
 
-			await Verify.VerifyAnalyzer(new[] { source, sharedCode }, expected);
+			await Verify.VerifyAnalyzer([source, sharedCode], expected);
 		}
 
 		[Fact]
 		public async Task StringNameOnOtherClass_Triggers()
 		{
-			var source = @"
-public partial class TestClass {
-    [Xunit.MemberData(""OtherData"", MemberType = typeof(OtherClass))]
-    public void TestMethod(int _) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1014")
-					.WithSpan(3, 23, 3, 34)
-					.WithArguments("OtherData", "OtherClass");
+			var source = /* lang=c#-test */ """
+				public partial class TestClass {
+				    [Xunit.MemberData({|#0:"OtherData"|}, MemberType = typeof(OtherClass))]
+				    public void TestMethod(int _) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1014").WithLocation(0).WithArguments("OtherData", "OtherClass");
 
-			await Verify.VerifyAnalyzer(new[] { source, sharedCode }, expected);
+			await Verify.VerifyAnalyzer([source, sharedCode], expected);
 		}
 	}
 
 	public class X1015_MemberDataMustReferenceExistingMember
 	{
 		[Theory]
-		[InlineData("")]
-		[InlineData(", MemberType = typeof(TestClass)")]
+		[InlineData(/* lang=c#-test */ "")]
+		[InlineData(/* lang=c#-test */ ", MemberType = typeof(TestClass)")]
 		public async Task InvalidStringNameOnSameClass_Triggers(string memberType)
 		{
-			var source = @$"
-public class TestClass {{
-    [Xunit.MemberData(""BogusName""{memberType})]
-    public void TestMethod() {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1015")
-					.WithSpan(3, 6, 3, 35 + memberType.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("BogusName", "TestClass");
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    [{{|#0:Xunit.MemberData("BogusName"{0})|}}]
+				    public void TestMethod() {{ }}
+				}}
+				""", memberType);
+			var expected = Verify.Diagnostic("xUnit1015").WithLocation(0).WithArguments("BogusName", "TestClass");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -105,39 +97,35 @@ public void TestMethod() {{ }}
 		[Fact]
 		public async Task InvalidStringNameOnOtherClass_Triggers()
 		{
-			var source1 = @"
-public class TestClass {
-    [Xunit.MemberData(""BogusName"", MemberType = typeof(OtherClass))]
-    public void TestMethod() { }
-}";
-			var source2 = "public class OtherClass { }";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1015")
-					.WithSpan(3, 6, 3, 68)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("BogusName", "OtherClass");
+			var source1 = /* lang=c#-test */ """
+				public class TestClass {
+				    [{|#0:Xunit.MemberData("BogusName", MemberType = typeof(OtherClass))|}]
+				    public void TestMethod() { }
+				}
+				""";
+			var source2 = /* lang=c#-test */ """
+				public class OtherClass { }
+				""";
+			var expected = Verify.Diagnostic("xUnit1015").WithLocation(0).WithArguments("BogusName", "OtherClass");
 
-			await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+			await Verify.VerifyAnalyzer([source1, source2], expected);
 		}
 
 		[Fact]
 		public async Task InvalidNameofOnOtherClass_Triggers()
 		{
-			var source1 = @"
-public class TestClass {
-    [Xunit.MemberData(nameof(TestClass.TestMethod), MemberType = typeof(OtherClass))]
-    public void TestMethod() { }
-}";
-			var source2 = "public class OtherClass { }";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1015")
-					.WithSpan(3, 6, 3, 85)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("TestMethod", "OtherClass");
-
-			await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+			var source1 = /* lang=c#-test */ """
+				public class TestClass {
+				    [{|#0:Xunit.MemberData(nameof(TestClass.TestMethod), MemberType = typeof(OtherClass))|}]
+				    public void TestMethod() { }
+				}
+				""";
+			var source2 = /* lang=c#-test */ """
+				public class OtherClass { }
+				""";
+			var expected = Verify.Diagnostic("xUnit1015").WithLocation(0).WithArguments("TestMethod", "OtherClass");
+
+			await Verify.VerifyAnalyzer([source1, source2], expected);
 		}
 	}
 
@@ -146,21 +134,22 @@ public class X1016_MemberDataMustReferencePublicMember
 		[Fact]
 		public async Task PublicMember_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> Data = null;
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> Data = null;
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
+				    [Xunit.MemberData(nameof(Data))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		public static MatrixTheoryData<string, string> NonPublicTestData =>
 			new(
-				new[] { "", "private", "protected", "internal", "protected internal" },
-				new[] { "{|xUnit1014:\"Data\"|}", "DataNameConst", "DataNameofConst", "nameof(Data)", "nameof(TestClass.Data)", "OtherClass.Data", "nameof(OtherClass.Data)" }
+				/* lang=c#-test */ ["", "private", "protected", "internal", "protected internal"],
+				/* lang=c#-test */ ["{|xUnit1014:\"Data\"|}", "DataNameConst", "DataNameofConst", "nameof(Data)", "nameof(TestClass.Data)", "OtherClass.Data", "nameof(OtherClass.Data)"]
 			);
 
 		[Theory]
@@ -172,24 +161,22 @@ public async Task NonPublicNameExpression_Triggers(
 			TestFileMarkupParser.GetPositionsAndSpans(dataNameExpression, out var parsedDataNameExpression, out _, out _);
 			var dataNameExpressionLength = parsedDataNameExpression.Length;
 
-			var source1 = $@"
-public class TestClass {{
-    const string DataNameConst = ""Data"";
-    const string DataNameofConst = nameof(Data);
+			var source1 = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    const string DataNameConst = "Data";
+				    const string DataNameofConst = nameof(Data);
 
-    {accessModifier} static Xunit.TheoryData<int> Data = null;
+				    {0} static Xunit.TheoryData<int> Data = null;
 
-    [Xunit.MemberData({dataNameExpression})]
-    public void TestMethod(int _) {{ }}
-}}";
-			var source2 = @"public static class OtherClass { public const string Data = ""Data""; }";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1016")
-					.WithSpan(8, 6, 8, 24 + dataNameExpressionLength)
-					.WithSeverity(DiagnosticSeverity.Error);
+				    [{{|xUnit1016:Xunit.MemberData({1})|}}]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", accessModifier, dataNameExpression);
+			var source2 = /* lang=c#-test */ """
+				public static class OtherClass { public const string Data = "Data"; }
+				""";
 
-			await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+			await Verify.VerifyAnalyzer([source1, source2]);
 		}
 	}
 
@@ -198,13 +185,14 @@ public class X1017_MemberDataMustReferenceStaticMember
 		[Fact]
 		public async Task StaticMember_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> Data = null;
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> Data = null;
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
+				    [Xunit.MemberData(nameof(Data))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -212,62 +200,55 @@ public void TestMethod(int _) { }
 		[Fact]
 		public async Task InstanceMember_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    public Xunit.TheoryData<int> Data = null;
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public Xunit.TheoryData<int> Data = null;
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1017")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error);
+				    [{|xUnit1017:Xunit.MemberData(nameof(Data))|}]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
 	public class X1018_MemberDataMustReferenceValidMemberKind
 	{
 		[Theory]
-		[InlineData("Data;")]
-		[InlineData("Data { get; set; }")]
-		[InlineData("Data() { return null; }")]
+		[InlineData(/* lang=c#-test */ "Data;")]
+		[InlineData(/* lang=c#-test */ "Data { get; set; }")]
+		[InlineData(/* lang=c#-test */ "Data() { return null; }")]
 		public async Task ValidMemberKind_DoesNotTrigger(string member)
 		{
-			var source = $@"
-public class TestClass {{
-    public static Xunit.TheoryData<int> {member}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> {0}
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(Data))]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", member);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("public delegate System.Collections.Generic.IEnumerable<object[]> Data();")]
-		[InlineData("public static class Data { }")]
-		[InlineData("public static event System.EventHandler Data;")]
+		[InlineData(/* lang=c#-test */ "public delegate System.Collections.Generic.IEnumerable<object[]> Data();")]
+		[InlineData(/* lang=c#-test */ "public static class Data { }")]
+		[InlineData(/* lang=c#-test */ "public static event System.EventHandler Data;")]
 		public async Task InvalidMemberKind_Triggers(string member)
 		{
-			var source = $@"
-public class TestClass {{
-    {member}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    {0}
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod() {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1018")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error);
+				    [{{|xUnit1018:Xunit.MemberData(nameof(Data))|}}]
+				    public void TestMethod() {{ }}
+				}}
+				""", member);
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
@@ -280,130 +261,115 @@ public class X1019_MemberDataMustReferenceMemberOfValidType
 		[Fact]
 		public async Task TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> Data;
+				public class TestClass {
+				    public static TheoryData<int> Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
+				    [MemberData(nameof(Data))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("Task")]
-		[InlineData("ValueTask")]
+		[InlineData(/* lang=c#-test */ "Task")]
+		[InlineData(/* lang=c#-test */ "ValueTask")]
 		public async Task Async_TheoryData_TriggersInV2_DoesNotTriggerInV3(string taskType)
 		{
-			var source = @$"
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using System.Threading.Tasks;
+				using Xunit;
 
-public class TestClass {{
-    public static {taskType}<TheoryData<int>> Data;
+				public class TestClass {{
+				    public static {0}<TheoryData<int>> Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}";
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1019")
-					.WithSpan(9, 6, 9, 30)
-					.WithArguments("'System.Collections.Generic.IEnumerable<object[]>'", $"System.Threading.Tasks.{taskType}<Xunit.TheoryData<int>>");
+				    [{{|#0:MemberData(nameof(Data))|}}]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", taskType);
+			var expectedV2 = Verify.Diagnostic("xUnit1019").WithLocation(0).WithArguments("'System.Collections.Generic.IEnumerable<object[]>'", $"System.Threading.Tasks.{taskType}<Xunit.TheoryData<int>>");
 
 			await Verify.VerifyAnalyzerV2(LanguageVersion.CSharp9, source, expectedV2);
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, source);
 		}
 
 		[Theory]
-		[InlineData("List<TheoryDataRow<int, string>>")]
-		[InlineData("IAsyncEnumerable<TheoryDataRow<int, string>>")]
+		[InlineData(/* lang=c#-test */ "List<TheoryDataRow<int, string>>")]
+		[InlineData(/* lang=c#-test */ "IAsyncEnumerable<TheoryDataRow<int, string>>")]
 		public async Task GenericTheoryDataRow_DoesNotTrigger(string dataType)
 		{
-			var source = @$"
-using System;
-using System.Collections.Generic;
-using Xunit;
-using Xunit.Sdk;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Collections.Generic;
+				using Xunit;
+				using Xunit.Sdk;
 
-public class TestClass
-{{
-    [Theory]
-    [MemberData(nameof(DataRowSource))]
-    public void SkippedDataRow(int x, string y)
-    {{ }}
+				public class TestClass {{
+				    [Theory]
+				    [MemberData(nameof(DataRowSource))]
+				    public void SkippedDataRow(int x, string y) {{ }}
 
-    public static {dataType} DataRowSource() {{
-        throw new NotImplementedException();
-    }}
-}}";
+				    public static {0} DataRowSource() {{
+				        throw new NotImplementedException();
+				    }}
+				}}
+				""", dataType);
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, source);
 		}
 
 		[Theory]
-		[InlineData("Task<List<TheoryDataRow<int, string>>>")]
-		[InlineData("ValueTask<IAsyncEnumerable<TheoryDataRow<int, string>>>")]
+		[InlineData(/* lang=c#-test */ "Task<List<TheoryDataRow<int, string>>>")]
+		[InlineData(/* lang=c#-test */ "ValueTask<IAsyncEnumerable<TheoryDataRow<int, string>>>")]
 		public async Task Async_GenericTheoryDataRow_DoesNotTrigger(string taskType)
 		{
-			var source = @$"
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Xunit;
-using Xunit.Sdk;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Collections.Generic;
+				using System.Threading.Tasks;
+				using Xunit;
+				using Xunit.Sdk;
 
-public class TestClass
-{{
-    [Theory]
-    [MemberData(nameof(DataRowSource))]
-    public void SkippedDataRow(int x, string y)
-    {{ }}
+				public class TestClass {{
+				    [Theory]
+				    [MemberData(nameof(DataRowSource))]
+				    public void SkippedDataRow(int x, string y) {{ }}
 
-    public static async {taskType} DataRowSource() {{
-        throw new NotImplementedException();
-    }}
-}}";
+				    public static async {0} DataRowSource() {{
+				        throw new NotImplementedException();
+				    }}
+				}}
+				""", taskType);
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, source);
 		}
 
 		[Theory]
-		[InlineData("System.Collections.Generic.IEnumerable<object>")]
-		[InlineData("object[]")]
-		[InlineData("object")]
-		[InlineData("System.Tuple<string, int>")]
-		[InlineData("System.Tuple<string, int>[]")]
+		[InlineData(/* lang=c#-test */ "System.Collections.Generic.IEnumerable<object>")]
+		[InlineData(/* lang=c#-test */ "object[]")]
+		[InlineData(/* lang=c#-test */ "object")]
+		[InlineData(/* lang=c#-test */ "System.Tuple<string, int>")]
+		[InlineData(/* lang=c#-test */ "System.Tuple<string, int>[]")]
 		public async Task InvalidMemberType_Triggers(string memberType)
 		{
-			var source = $@"
-public class TestClass {{
-    public static {memberType} Data;
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    public static {0} Data;
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod() {{ }}
-}}";
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1019")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("'System.Collections.Generic.IEnumerable<object[]>'", memberType);
+				    [{{|#0:Xunit.MemberData(nameof(Data))|}}]
+				    public void TestMethod() {{ }}
+				}}
+				""", memberType);
+			var expectedV2 = Verify.Diagnostic("xUnit1019").WithLocation(0).WithArguments("'System.Collections.Generic.IEnumerable<object[]>'", memberType);
+			var expectedV3 = Verify.Diagnostic("xUnit1019").WithLocation(0).WithArguments("'System.Collections.Generic.IEnumerable<object[]>', 'System.Collections.Generic.IAsyncEnumerable<object[]>', 'System.Collections.Generic.IEnumerable<Xunit.ITheoryDataRow>', or 'System.Collections.Generic.IAsyncEnumerable<Xunit.ITheoryDataRow>'", memberType);
 
 			await Verify.VerifyAnalyzerV2(source, expectedV2);
-
-			var expectedV3 =
-				Verify
-					.Diagnostic("xUnit1019")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("'System.Collections.Generic.IEnumerable<object[]>', 'System.Collections.Generic.IAsyncEnumerable<object[]>', 'System.Collections.Generic.IEnumerable<Xunit.ITheoryDataRow>', or 'System.Collections.Generic.IAsyncEnumerable<Xunit.ITheoryDataRow>'", memberType);
-
 			await Verify.VerifyAnalyzerV3(source, expectedV3);
 		}
 	}
@@ -413,189 +379,153 @@ public class X1020_MemberDataPropertyMustHaveGetter
 		[Fact]
 		public async Task PropertyWithoutGetter_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> Data { set { } }
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> Data { set { } }
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1020")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error);
+				    [{|xUnit1020:Xunit.MemberData(nameof(Data))|}]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("internal")]
-		[InlineData("protected")]
-		[InlineData("private")]
+		[InlineData(/* lang=c#-test */ "internal")]
+		[InlineData(/* lang=c#-test */ "protected")]
+		[InlineData(/* lang=c#-test */ "private")]
 		public async Task PropertyWithNonPublicGetter_Triggers(string visibility)
 		{
-			var source = $@"
-public class TestClass {{
-    public static Xunit.TheoryData<int> Data {{ {visibility} get {{ return null; }} set {{ }} }}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> Data {{ {0} get {{ return null; }} set {{ }} }}
 
-    [Xunit.MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1020")
-					.WithSpan(5, 6, 5, 36)
-					.WithSeverity(DiagnosticSeverity.Error);
+				    [{{|xUnit1020:Xunit.MemberData(nameof(Data))|}}]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", visibility);
 
-			await Verify.VerifyAnalyzer(source, expected);
+			await Verify.VerifyAnalyzer(source);
 		}
 	}
 
 	public class X1021_MemberDataNonMethodShouldNotHaveParameters
 	{
 		[Theory]
-		[InlineData("1")]                   // implicit params
-		[InlineData("new object[] { 1 }")]  // explicit params
+		[InlineData(/* lang=c#-test */ "1")]                   // implicit params
+		[InlineData(/* lang=c#-test */ "new object[] { 1 }")]  // explicit params
 		public async Task MethodMemberWithParameters_DoesNotTrigger(string parameter)
 		{
-			var source = @$"
-public class TestClass {{
-    private static void TestData() {{ }}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    private static void TestData() {{ }}
 
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
-
-    [Xunit.MemberData(nameof(TestData), {parameter})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
 
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameter);
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("1, 2")]                   // implicit params
-		[InlineData("new object[] { 1, 2 }")]  // explicit params
+		[InlineData(/* lang=c#-test */ "1, 2")]                   // implicit params
+		[InlineData(/* lang=c#-test */ "new object[] { 1, 2 }")]  // explicit params
 		public async Task MethodMemberWithParamsArrayParameters_DoesNotTrigger(string parameters)
 		{
-			var source = @$"
-public class TestClass {{
-    public static Xunit.TheoryData<int> TestData(params int[] n) => new Xunit.TheoryData<int> {{ n[0] }};
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> TestData(params int[] n) => new Xunit.TheoryData<int> {{ n[0] }};
 
-    [Xunit.MemberData(nameof(TestData), {parameters})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameters);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("1")]                   // implicit params
-		[InlineData("new object[] { 1 }")]  // explicit params
+		[InlineData(/* lang=c#-test */ "1")]                   // implicit params
+		[InlineData(/* lang=c#-test */ "new object[] { 1 }")]  // explicit params
 		public async Task MethodMemberOnBaseType_DoesNotTrigger(string parameter)
 		{
-			var source = $@"
-public class TestClassBase {{
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
-}}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClassBase {{
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
+				}}
 
-public class TestClass : TestClassBase {{
-    private static void TestData() {{ }}
+				public class TestClass : TestClassBase {{
+				    private static void TestData() {{ }}
 
-    [Xunit.MemberData(nameof(TestData), {parameter})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameter);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("'a', 123")]
-		[InlineData("new object[] {{ 'a', 123 }}")]
-		[InlineData("{0}: new object[] {{ 'a', 123 }}")]
+		[InlineData(/* lang=c#-test */ "'a', 123")]
+		[InlineData(/* lang=c#-test */ "new object[] {{ 'a', 123 }}")]
+		[InlineData(/* lang=c#-test */ "{0}: new object[] {{ 'a', 123 }}")]
 		public async Task FieldMemberWithParameters_Triggers(string paramsArgument)
 		{
-			var sourceTemplate = @"
-public class TestClass {{
-    public static Xunit.TheoryData<int> Data;
-
-    [Xunit.MemberData(nameof(Data), {0}, MemberType = typeof(TestClass))]
-    public void TestMethod(int _) {{ }}
-}}";
+			var sourceTemplate = /* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> Data;
 
-			var argV2 = string.Format(paramsArgument, "parameters");
-			var sourceV2 = string.Format(sourceTemplate, argV2);
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1021")
-					.WithSpan(5, 37, 5, 37 + argV2.Length)
-					.WithSeverity(DiagnosticSeverity.Warning);
+				    [Xunit.MemberData(nameof(Data), {{|xUnit1021:{0}|}}, MemberType = typeof(TestClass))]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""";
 
-			await Verify.VerifyAnalyzerV2(sourceV2, expectedV2);
-
-			var argV3 = string.Format(paramsArgument, "arguments");
-			var sourceV3 = string.Format(sourceTemplate, argV3);
-			var expectedV3 =
-				Verify
-					.Diagnostic("xUnit1021")
-					.WithSpan(5, 37, 5, 37 + argV3.Length)
-					.WithSeverity(DiagnosticSeverity.Warning);
-
-			await Verify.VerifyAnalyzerV3(sourceV3, expectedV3);
+			await Verify.VerifyAnalyzerV2(string.Format(sourceTemplate, string.Format(paramsArgument, "parameters")));
+			await Verify.VerifyAnalyzerV3(string.Format(sourceTemplate, string.Format(paramsArgument, "arguments")));
 		}
 
 		[Theory]
-		[InlineData("'a', 123")]
-		[InlineData("new object[] {{ 'a', 123 }}")]
-		[InlineData("{0}: new object[] {{ 'a', 123 }}")]
+		[InlineData(/* lang=c#-test */ "'a', 123")]
+		[InlineData(/* lang=c#-test */ "new object[] {{ 'a', 123 }}")]
+		[InlineData(/* lang=c#-test */ "{0}: new object[] {{ 'a', 123 }}")]
 		public async Task PropertyMemberWithParameters_Triggers(string paramsArgument)
 		{
-			var sourceTemplate = @"
-public class TestClass {{
-    public static Xunit.TheoryData<int> Data {{ get; set; }}
-
-    [Xunit.MemberData(nameof(Data), {0}, MemberType = typeof(TestClass))]
-    public void TestMethod(int _) {{ }}
-}}";
-
-			var argV2 = string.Format(paramsArgument, "parameters");
-			var sourceV2 = string.Format(sourceTemplate, argV2);
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1021")
-					.WithSpan(5, 37, 5, 37 + argV2.Length)
-					.WithSeverity(DiagnosticSeverity.Warning);
+			var sourceTemplate = /* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> Data {{ get; set; }}
 
-			await Verify.VerifyAnalyzerV2(sourceV2, expectedV2);
+				    [Xunit.MemberData(nameof(Data), {{|xUnit1021:{0}|}}, MemberType = typeof(TestClass))]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""";
 
-			var argV3 = string.Format(paramsArgument, "arguments");
-			var sourceV3 = string.Format(sourceTemplate, argV3);
-			var expectedV3 =
-				Verify
-					.Diagnostic("xUnit1021")
-					.WithSpan(5, 37, 5, 37 + argV3.Length)
-					.WithSeverity(DiagnosticSeverity.Warning);
-
-			await Verify.VerifyAnalyzerV3(sourceV3, expectedV3);
+			await Verify.VerifyAnalyzerV2(string.Format(sourceTemplate, string.Format(paramsArgument, "parameters")));
+			await Verify.VerifyAnalyzerV3(string.Format(sourceTemplate, string.Format(paramsArgument, "arguments")));
 		}
 	}
 
 	public class X1034_MemberDataArgumentsMustMatchMethodParameters_NullShouldNotBeUsedForIncompatibleParameter
 	{
 		[Theory]
-		[InlineData("", "string")]
-		[InlineData("#nullable enable", "string?")]
+		[InlineData(/* lang=c#-test */ "", "string")]
+		[InlineData(/* lang=c#-test */ "#nullable enable", "string?")]
 		public async Task PassingNullForNullableReferenceType_DoesNotTrigger(
 			string header,
 			string argumentType)
 		{
-			var source = $@"
-{header}
-public class TestClass {{
-    public static Xunit.TheoryData<int> TestData({argumentType} f) => new Xunit.TheoryData<int> {{ 42 }};
+			var source = string.Format(/* lang=c#-test */ """
+				{0}
+
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> TestData({1} f) => new Xunit.TheoryData<int> {{ 42 }};
 
-    [Xunit.MemberData(nameof(TestData), new object[] {{ null }})]
-    public void TestMethod(int _) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData), new object[] {{ null }})]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", header, argumentType);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -603,20 +533,15 @@ public void TestMethod(int _) {{ }}
 		[Fact]
 		public async Task PassingNullForStructType_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> { n };
-
-    [Xunit.MemberData(nameof(TestData), new object[] { null })]
-    public void TestMethod(int _) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> { n };
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1034")
-					.WithSpan(5, 56, 5, 60)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("n", "int");
+				    [Xunit.MemberData(nameof(TestData), new object[] { {|#0:null|} })]
+				    public void TestMethod(int _) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1034").WithLocation(0).WithArguments("n", "int");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -624,22 +549,17 @@ public void TestMethod(int _) { }
 		[Fact]
 		public async Task PassingNullForNonNullableReferenceType_Triggers()
 		{
-			var source = @"
-#nullable enable
-public class TestClass {
-    public static Xunit.TheoryData<string> TestData(string f) => new Xunit.TheoryData<string> { f };
+			var source = /* lang=c#-test */ """
+				#nullable enable
 
-    [Xunit.MemberData(nameof(TestData), new object[] { null })]
-    public void TestMethod(string _) { }
-}
-#nullable restore";
+				public class TestClass {
+				    public static Xunit.TheoryData<string> TestData(string f) => new Xunit.TheoryData<string> { f };
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1034")
-					.WithSpan(6, 56, 6, 60)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("f", "string");
+				    [Xunit.MemberData(nameof(TestData), new object[] { {|#0:null|} })]
+				    public void TestMethod(string _) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1034").WithLocation(0).WithArguments("f", "string");
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
@@ -649,74 +569,73 @@ public class X1035_MemberDataArgumentsMustMatchMethodParameters_IncompatibleValu
 	{
 		// https://github.com/xunit/xunit/issues/2817
 		[Theory]
-		[InlineData("Foo.Bar")]
-		[InlineData("(Foo)42")]
+		[InlineData(/* lang=c#-test */ "Foo.Bar")]
+		[InlineData(/* lang=c#-test */ "(Foo)42")]
 		public async Task ValidEnumValue_DoesNotTrigger(string enumValue)
 		{
-			var source = $@"
-using System;
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [MemberData(nameof(SomeData), {enumValue})]
-    public void TestMethod(int _) {{ }}
+				public class TestClass {{
+				    [Theory]
+				    [MemberData(nameof(SomeData), {0})]
+				    public void TestMethod(int _) {{ }}
 
-    public enum Foo {{ Bar }}
+				    public enum Foo {{ Bar }}
 
-    public static Xunit.TheoryData<int> SomeData(Foo foo) => new Xunit.TheoryData<int>();
-}}";
+				    public static Xunit.TheoryData<int> SomeData(Foo foo) => new Xunit.TheoryData<int>();
+				}}
+				""", enumValue);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		// https://github.com/xunit/xunit/issues/2852
 		[Theory]
-		[InlineData("")]
-		[InlineData("#nullable enable")]
+		[InlineData(/* lang=c#-test */ "")]
+		[InlineData(/* lang=c#-test */ "#nullable enable")]
 		public async Task ArrayInitializerWithCorrectType_DoesNotTrigger(string header)
 		{
-			var source = $@"
-{header}
+			var source = string.Format(/* lang=c#-test */ """
+				{0}
 
-using System.Collections.Generic;
-using Xunit;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static TheoryData<int> GetSequences(IEnumerable<int> seq) => new TheoryData<int> {{ 42, 2112 }};
+				public class TestClass {{
+				    public static TheoryData<int> GetSequences(IEnumerable<int> seq) => new TheoryData<int> {{ 42, 2112 }};
 
-    [Theory]
-    [MemberData(nameof(GetSequences), new int[] {{ 1, 2 }})]
-    public void Test(int value) {{ }}
-}}";
+				    [Theory]
+				    [MemberData(nameof(GetSequences), new int[] {{ 1, 2 }})]
+				    public void Test(int value) {{ }}
+				}}
+				""", header);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
 
 		[Theory]
-		[InlineData("")]
-		[InlineData("#nullable enable")]
+		[InlineData(/* lang=c#-test */ "")]
+		[InlineData(/* lang=c#-test */ "#nullable enable")]
 		public async Task ArrayInitializerWithIncorrectType_Triggers(string header)
 		{
-			var source = $@"
-{header}
+			var source = string.Format(/* lang=c#-test */ """
+				{0}
 
-using System.Collections.Generic;
-using Xunit;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static TheoryData<int> GetSequences(IEnumerable<int> seq) => new TheoryData<int> {{ 42, 2112 }};
+				public class TestClass {{
+				    public static TheoryData<int> GetSequences(IEnumerable<int> seq) => new TheoryData<int> {{ 42, 2112 }};
 
-    [Theory]
-    [MemberData(nameof(GetSequences), new char[] {{ 'a', 'b' }})]
-    public void Test(int value) {{ }}
-}}";
-			var expected =
-				Verify
-					.Diagnostic("xUnit1035")
-					.WithSpan(11, 39, 11, 62)
-					.WithArguments("seq", "System.Collections.Generic.IEnumerable<int>");
+				    [Theory]
+				    [MemberData(nameof(GetSequences), {{|#0:new char[] {{ 'a', 'b' }}|}})]
+				    public void Test(int value) {{ }}
+				}}
+				""", header);
+			var expected = Verify.Diagnostic("xUnit1035").WithLocation(0).WithArguments("seq", "System.Collections.Generic.IEnumerable<int>");
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
@@ -724,19 +643,15 @@ public void Test(int value) {{ }}
 		[Fact]
 		public async Task ValidMemberWithIncorrectArgumentTypes_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> TestData(string n) => new Xunit.TheoryData<int> { n.Length };
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> TestData(string n) => new Xunit.TheoryData<int> { n.Length };
 
-    [Xunit.MemberData(nameof(TestData), new object[] { 1 })]
-    public void TestMethod(int n) { }
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1035")
-					.WithSpan(5, 56, 5, 57)
-					.WithArguments("n", "string");
+				    [Xunit.MemberData(nameof(TestData), new object[] { {|#0:1|} })]
+				    public void TestMethod(int n) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1035").WithLocation(0).WithArguments("n", "string");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -744,19 +659,15 @@ public void TestMethod(int n) { }
 		[Fact]
 		public async Task ValidMemberWithIncorrectArgumentTypesParams_Triggers()
 		{
-			var source = @"
-public class TestClass {
-    public static Xunit.TheoryData<int> TestData(params int[] n) => new Xunit.TheoryData<int> { n[0] };
-
-    [Xunit.MemberData(nameof(TestData), new object[] { 1, ""bob"" })]
-    public void TestMethod(int n) { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public static Xunit.TheoryData<int> TestData(params int[] n) => new Xunit.TheoryData<int> { n[0] };
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1035")
-					.WithSpan(5, 59, 5, 64)
-					.WithArguments("n", "int");
+				    [Xunit.MemberData(nameof(TestData), new object[] { 1, {|#0:"bob"|} })]
+				    public void TestMethod(int n) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1035").WithLocation(0).WithArguments("n", "int");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -765,61 +676,57 @@ public void TestMethod(int n) { }
 	public class X1036_MemberDataArgumentsMustMatchMethodParameters_ExtraValue
 	{
 		[Theory]
-		[InlineData("1")]
-		[InlineData("new object[] { 1 }")]
+		[InlineData(/* lang=c#-test */ "1")]
+		[InlineData(/* lang=c#-test */ "new object[] { 1 }")]
 		public async Task ValidArgumentCount_DoesNotTrigger(string parameter)
 		{
-			var source = $@"
-public class TestClass {{
-    private static void TestData() {{ }}
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    private static void TestData() {{ }}
 
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
 
-    [Xunit.MemberData(nameof(TestData), {parameter})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameter);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
-		[InlineData("1")]
-		[InlineData("new object[] { 1 }")]
+		[InlineData(/* lang=c#-test */ "1")]
+		[InlineData(/* lang=c#-test */ "new object[] { 1 }")]
 		public async Task ValidArgumentCount_InNullableContext_DoesNotTrigger(string parameter)
 		{
-			var source = $@"
-#nullable enable
-public class TestClass {{
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
+
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
 
-    [Xunit.MemberData(nameof(TestData), {parameter})]
-    public void TestMethod(int n) {{ }}
-}}
-#nullable restore";
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameter);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
 
 		[Theory]
-		[InlineData("1, 2", 44)]
-		[InlineData("new object[] { 1, 2 }", 59)]
-		public async Task TooManyArguments_Triggers(
-			string parameters,
-			int startColumn)
-		{
-			var source = $@"
-public class TestClass {{
-    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
-
-    [Xunit.MemberData(nameof(TestData), {parameters})]
-    public void TestMethod(int n) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1036")
-						.WithSpan(5, startColumn, 5, startColumn + 1)
-						.WithArguments("2");
+		[InlineData(/* lang=c#-test */ "1, {|#0:2|}")]
+		[InlineData(/* lang=c#-test */ "new object[] { 1, {|#0:2|} }")]
+		public async Task TooManyArguments_Triggers(string parameters)
+		{
+			var source = string.Format(/* lang=c#-test */ """
+				public class TestClass {{
+				    public static Xunit.TheoryData<int> TestData(int n) => new Xunit.TheoryData<int> {{ n }};
+
+				    [Xunit.MemberData(nameof(TestData), {0})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", parameters);
+			var expected = Verify.Diagnostic("xUnit1036").WithLocation(0).WithArguments("2");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -829,10 +736,10 @@ public class X1037_TheoryDataTypeArgumentsMustMatchTestMethodParameters_TooFewTy
 	{
 		public static TheoryData<string, string> MemberSyntaxAndArgs = new()
 		{
-			{ " = ", "" },              // Field
-			{ " => ", "" },             // Property
-			{ "() => ", "" },           // Method w/o args
-			{ "(int n) => ", ", 42" },  // Method w/ args
+			/* lang=c#-test */ { " = ", "" },              // Field
+			/* lang=c#-test */ { " => ", "" },             // Property
+			/* lang=c#-test */ { "() => ", "" },           // Method w/o args
+			/* lang=c#-test */ { "(int n) => ", ", 42" },  // Method w/ args
 		};
 
 		[Theory]
@@ -841,22 +748,17 @@ public async Task ValidTheoryDataMemberWithNotEnoughTypeParameters_Triggers(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {{
-    public static TheoryData<int> TestData{memberSyntax}new TheoryData<int>();
+				public class TestClass {{
+				    public static TheoryData<int> TestData{0}new TheoryData<int>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, string f) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1037")
-					.WithSpan(7, 6, 7, 34 + memberArgs.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryData");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void TestMethod(int n, string f) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1037").WithLocation(0).WithArguments("Xunit.TheoryData");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -867,23 +769,18 @@ public async Task ValidTheoryDataRowMemberWithNotEnoughTypeParameters_Triggers(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<int>> TestData{memberSyntax}null;
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<int>> TestData{0}null;
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, string f) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1037")
-					.WithSpan(8, 6, 8, 34 + memberArgs.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void TestMethod(int n, string f) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1037").WithLocation(0).WithArguments("Xunit.TheoryDataRow");
 
 			await Verify.VerifyAnalyzerV3(source, expected);
 		}
@@ -894,24 +791,19 @@ public async Task ValidSubclassedTheoryDataMemberWithNotEnoughTypeParameters_Tri
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData<T, U> : TheoryData<T> {{ }}
+				public class DerivedTheoryData<T, U> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static DerivedTheoryData<int, string> TestData{memberSyntax}new DerivedTheoryData<int, string>();
+				public class TestClass {{
+				    public static DerivedTheoryData<int, string> TestData{0}new DerivedTheoryData<int, string>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, string f) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1037")
-					.WithSpan(9, 6, 9, 34 + memberArgs.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryData");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void TestMethod(int n, string f) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1037").WithLocation(0).WithArguments("Xunit.TheoryData");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -919,30 +811,27 @@ public void TestMethod(int n, string f) {{ }}
 
 	public class X1038_TheoryDataTypeArgumentsMustMatchTestMethodParameters_ExtraTypeParameters
 	{
-		public static TheoryData<string, string> MemberSyntaxAndArgs() =>
-			new() {
-				{ " = ", "" },              // Field
-				{ " => ", "" },             // Property
-				{ "() => ", "" },           // Method w/o args
-				{ "(int n) => ", ", 42" },  // Method w/ args
-			};
-
-		public static MatrixTheoryData<(string syntax, string args), string> MemberSyntaxAndArgs_WithTheoryDataType(string theoryDataTypes) =>
-			new(
-				new[]
-				{
-					( " = ", "" ),              // Field
-					( " => ", "" ),             // Property
-					( "() => ", "" ),           // Method w/o args
-					( "(int n) => ", ", 42" ),  // Method w/ args
-				},
-				new[]
-				{
-					$"TheoryData<{theoryDataTypes}>",
-					"DerivedTheoryData",
-					$"DerivedTheoryData<{theoryDataTypes}>"
-				}
-			);
+		public static TheoryData<string, string> MemberSyntaxAndArgs() => new()
+		{
+			{ " = ", "" },              // Field
+			{ " => ", "" },             // Property
+			{ "() => ", "" },           // Method w/o args
+			{ "(int n) => ", ", 42" },  // Method w/ args
+		};
+
+		public static MatrixTheoryData<(string syntax, string args), string> MemberSyntaxAndArgs_WithTheoryDataType(string theoryDataTypes) => new(
+			[
+				(" = ", ""),              // Field
+				(" => ", ""),             // Property
+				("() => ", ""),           // Method w/o args
+				("(int n) => ", ", 42"),  // Method w/ args
+			],
+			[
+				$"TheoryData<{theoryDataTypes}>",
+				"DerivedTheoryData",
+				$"DerivedTheoryData<{theoryDataTypes}>"
+			]
+		);
 
 		[Theory]
 		[MemberData(nameof(MemberSyntaxAndArgs_WithTheoryDataType), "int", DisableDiscoveryEnumeration = true)]
@@ -950,18 +839,19 @@ public async Task ValidTheoryData_DoesNotTrigger(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int> {{ }}
-public class DerivedTheoryData<T> : TheoryData<T> {{ }}
+				public class DerivedTheoryData : TheoryData<int> {{ }}
+				public class DerivedTheoryData<T> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -972,16 +862,17 @@ public async Task ValidTheoryDataRow_DoesNotTrigger(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<int>> TestData{memberSyntax}new List<TheoryDataRow<int>>();
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<int>> TestData{0}new List<TheoryDataRow<int>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -992,18 +883,19 @@ public async Task ValidTheoryDataWithOptionalParameters_DoesNotTrigger(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int> {{ }}
-public class DerivedTheoryData<T> : TheoryData<T> {{ }}
+				public class DerivedTheoryData : TheoryData<int> {{ }}
+				public class DerivedTheoryData<T> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(int n, int a = 0) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, int a = 0) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1014,16 +906,17 @@ public async Task ValidTheoryDataRowWithOptionalParameters_DoesNotTrigger(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static TheoryDataRow<int>[] TestData{memberSyntax}new TheoryDataRow<int>[0];
+				public class TestClass {{
+				    public static TheoryDataRow<int>[] TestData{0}new TheoryDataRow<int>[0];
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, int a = 0) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, int a = 0) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1034,18 +927,19 @@ public async Task ValidTheoryDataWithNoValuesForParamsArray_DoesNotTrigger(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int> {{ }}
-public class DerivedTheoryData<T> : TheoryData<T> {{ }}
+				public class DerivedTheoryData : TheoryData<int> {{ }}
+				public class DerivedTheoryData<T> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(int n, params int[] a) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, params int[] a) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1056,16 +950,17 @@ public async Task ValidTheoryDataRowWithNoValuesForParamsArray_DoesNotTrigger(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static ICollection<TheoryDataRow<int>> TestData{memberSyntax}new List<TheoryDataRow<int>>();
+				public class TestClass {{
+				    public static ICollection<TheoryDataRow<int>> TestData{0}new List<TheoryDataRow<int>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, params int[] a) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, params int[] a) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1076,18 +971,19 @@ public async Task ValidTheoryDataWithSingleValueForParamsArray_DoesNotTrigger(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int, int> {{ }}
-public class DerivedTheoryData<T1, T2> : TheoryData<T1, T2> {{ }}
+				public class DerivedTheoryData : TheoryData<int, int> {{ }}
+				public class DerivedTheoryData<T1, T2> : TheoryData<T1, T2> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(int n, params int[] a) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, params int[] a) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1098,16 +994,17 @@ public async Task ValidTheoryDataRowWithSingleValueForParamsArray_DoesNotTrigger
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<int, int>> TestData{memberSyntax}new List<TheoryDataRow<int, int>>();
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<int, int>> TestData{0}new List<TheoryDataRow<int, int>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n, params int[] a) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n, params int[] a) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1118,18 +1015,19 @@ public async Task ValidTheoryDataWithGenericTestParameter_DoesNotTrigger(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int> {{ }}
-public class DerivedTheoryData<T> : TheoryData<T> {{ }}
+				public class DerivedTheoryData : TheoryData<int> {{ }}
+				public class DerivedTheoryData<T> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod<T>(T n) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod<T>(T n) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1140,16 +1038,17 @@ public async Task ValidTheoryDataRowWithGenericTestParameter_DoesNotTrigger(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static ISet<TheoryDataRow<int>> TestData{memberSyntax}new HashSet<TheoryDataRow<int>>();
+				public class TestClass {{
+				    public static ISet<TheoryDataRow<int>> TestData{0}new HashSet<TheoryDataRow<int>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod<T>(T n) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod<T>(T n) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1160,20 +1059,21 @@ public async Task ValidTheoryDataWithNullableGenericTestParameter_DoesNotTrigger
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-#nullable enable
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
 
-using Xunit;
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int> {{ }}
-public class DerivedTheoryData<T> : TheoryData<T> {{ }}
+				public class DerivedTheoryData : TheoryData<int> {{ }}
+				public class DerivedTheoryData<T> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [Xunit.MemberData(nameof(TestData){member.args})]
-    public void TestMethod<T>(T? n) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData){1})]
+				    public void TestMethod<T>(T? n) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp9, source);
 		}
@@ -1184,18 +1084,19 @@ public async Task ValidTheoryDataRowWithNullableGenericTestParameter_DoesNotTrig
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-#nullable enable
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
 
-using System.Collections.Generic;
-using Xunit;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<int>> TestData{memberSyntax}new List<TheoryDataRow<int>>();
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<int>> TestData{0}new List<TheoryDataRow<int>>();
 
-    [Xunit.MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod<T>(T? n) {{ }}
-}}";
+				    [Xunit.MemberData(nameof(TestData){1})]
+				    public void TestMethod<T>(T? n) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp9, source);
 		}
@@ -1206,17 +1107,18 @@ public async Task ValidTheoryDataDoubleGenericSubclassMember_DoesNotTrigger(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData<T, U> : TheoryData<T> {{ }}
+				public class DerivedTheoryData<T, U> : TheoryData<T> {{ }}
 
-public class TestClass {{
-    public static DerivedTheoryData<int, string> TestData{memberSyntax}new DerivedTheoryData<int, string>();
+				public class TestClass {{
+				    public static DerivedTheoryData<int, string> TestData{0}new DerivedTheoryData<int, string>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n) {{ }}
-}}";
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1224,20 +1126,21 @@ public void TestMethod(int n) {{ }}
 		[Fact]
 		public async Task WithIntArrayArguments_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-    public static TheoryData<IEnumerable<int>> GetSequences(IEnumerable<int> seq) => new TheoryData<IEnumerable<int>> { seq };
+				public class TestClass {
+				    public static TheoryData<IEnumerable<int>> GetSequences(IEnumerable<int> seq) => new TheoryData<IEnumerable<int>> { seq };
 
-    [Theory]
-    [MemberData(nameof(GetSequences), new[] { 1, 2 })]
-    [MemberData(nameof(GetSequences), new[] { 3, 4, 5 })]
-    public void Test(IEnumerable<int> seq) {
-        Assert.NotEmpty(seq);
-    }
-}";
+				    [Theory]
+				    [MemberData(nameof(GetSequences), new[] { 1, 2 })]
+				    [MemberData(nameof(GetSequences), new[] { 3, 4, 5 })]
+				    public void Test(IEnumerable<int> seq) {
+				        Assert.NotEmpty(seq);
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1248,25 +1151,20 @@ public async Task ValidSubclassTheoryDataMemberWithTooManyTypeParameters_Trigger
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class DerivedTheoryData : TheoryData<int, string> {{ }}
-public class DerivedTheoryData<T1, T2> : TheoryData<T1, T2> {{ }}
+				public class DerivedTheoryData : TheoryData<int, string> {{ }}
+				public class DerivedTheoryData<T1, T2> : TheoryData<T1, T2> {{ }}
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(int n) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(10, 6, 10, 34 + member.args.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryData");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
+			var expected = Verify.Diagnostic("xUnit1038").WithLocation(0).WithArguments("Xunit.TheoryData");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1277,23 +1175,18 @@ public async Task ValidSubclassTheoryDataRowMemberWithTooManyTypeParameters_Trig
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<int, string>> TestData{memberSyntax}new List<TheoryDataRow<int, string>>();
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<int, string>> TestData{0}new List<TheoryDataRow<int, string>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(int n) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(8, 6, 8, 34 + memberArgs.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void TestMethod(int n) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1038").WithLocation(0).WithArguments("Xunit.TheoryDataRow");
 
 			await Verify.VerifyAnalyzerV3(source, expected);
 		}
@@ -1304,25 +1197,20 @@ public async Task ExtraTheoryDataTypeExistsPastArrayForParamsArray_Triggers(
 			(string syntax, string args) member,
 			string theoryDataType)
 		{
-			var source = $@"
-using Xunit;
-
-public class DerivedTheoryData : TheoryData<int, string[], string> {{ }}
-public class DerivedTheoryData<T1, T2, T3> : TheoryData<T1, T2, T3> {{ }}
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {{
-    public static {theoryDataType} TestData{member.syntax}new {theoryDataType}();
+				public class DerivedTheoryData : TheoryData<int, string[], string> {{ }}
+				public class DerivedTheoryData<T1, T2, T3> : TheoryData<T1, T2, T3> {{ }}
 
-    [MemberData(nameof(TestData){member.args})]
-    public void PuzzleOne(int _1, params string[] _2) {{ }}
-}}";
+				public class TestClass {{
+				    public static {2} TestData{0}new {2}();
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(10, 6, 10, 34 + member.args.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryData");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void PuzzleOne(int _1, params string[] _2) {{ }}
+				}}
+				""", member.syntax, member.args, theoryDataType);
+			var expected = Verify.Diagnostic("xUnit1038").WithLocation(0).WithArguments("Xunit.TheoryData");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1333,23 +1221,18 @@ public async Task ExtraTheoryDataRowTypeExistsPastArrayForParamsArray_Triggers(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {{
-    public static ICollection<TheoryDataRow<int, string[], string>> TestData{memberSyntax}new TheoryDataRow<int, string[], string>[0];
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void PuzzleOne(int _1, params string[] _2) {{ }}
-}}";
+				public class TestClass {{
+				    public static ICollection<TheoryDataRow<int, string[], string>> TestData{0}new TheoryDataRow<int, string[], string>[0];
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1038")
-					.WithSpan(8, 6, 8, 34 + memberArgs.Length)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("Xunit.TheoryDataRow");
+				    [{{|#0:MemberData(nameof(TestData){1})|}}]
+				    public void PuzzleOne(int _1, params string[] _2) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1038").WithLocation(0).WithArguments("Xunit.TheoryDataRow");
 
 			await Verify.VerifyAnalyzerV3(source, expected);
 		}
@@ -1357,34 +1240,32 @@ public void PuzzleOne(int _1, params string[] _2) {{ }}
 
 	public class X1039_TheoryDataTypeArgumentsMustMatchTestMethodParameters_IncompatibleTypes
 	{
-		public static MatrixTheoryData<(string syntax, string args), string> TypeWithMemberSyntaxAndArgs =
-			new(
-				new[]
-				{
-					( " = ", "" ),              // Field
-					( " => ", "" ),             // Property
-					( "() => ", "" ),           // Method w/o args
-					( "(int n) => ", ", 42" ),  // Method w/ args
-				},
-				new[]
-				{
-					"int",
-					"System.Exception",
-				}
-			);
+		public static MatrixTheoryData<(string syntax, string args), string> TypeWithMemberSyntaxAndArgs = new(
+			[
+				(" = ", ""),              // Field
+				(" => ", ""),             // Property
+				("() => ", ""),           // Method w/o args
+				("(int n) => ", ", 42"),  // Method w/ args
+			],
+			[
+				"int",
+				"System.Exception",
+			]
+		);
 
 		[Fact]
 		public async Task WhenPassingMultipleValuesForParamsArray_TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryData<int, string, string> TestData = new TheoryData<int, string, string>();
+				public class TestClass {
+					public static TheoryData<int, string, string> TestData = new TheoryData<int, string, string>();
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params string[] _2) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1392,16 +1273,17 @@ public void PuzzleOne(int _1, params string[] _2) { }
 		[Fact]
 		public async Task WhenPassingMultipleValuesForParamsArray_TheoryDataRow_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-	public static IEnumerable<TheoryDataRow<int, string, string>> TestData = new List<TheoryDataRow<int, string, string>>();
+				public class TestClass {
+					public static IEnumerable<TheoryDataRow<int, string, string>> TestData = new List<TheoryDataRow<int, string, string>>();
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params string[] _2) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1409,15 +1291,16 @@ public void PuzzleOne(int _1, params string[] _2) { }
 		[Fact]
 		public async Task WhenPassingArrayForParamsArray_TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryData<int, string[]> TestData = new TheoryData<int, string[]>();
+				public class TestClass {
+					public static TheoryData<int, string[]> TestData = new TheoryData<int, string[]>();
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params string[] _2) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1425,15 +1308,16 @@ public void PuzzleOne(int _1, params string[] _2) { }
 		[Fact]
 		public async Task WhenPassingArrayForParamsArray_TheoryDataRow_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryDataRow<int, string[]>[] TestData = new TheoryDataRow<int, string[]>[0];
+				public class TestClass {
+					public static TheoryDataRow<int, string[]>[] TestData = new TheoryDataRow<int, string[]>[0];
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params string[] _2) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1441,15 +1325,16 @@ public void PuzzleOne(int _1, params string[] _2) { }
 		[Fact]
 		public async Task WhenPassingTupleWithoutFieldNames_TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryData<(int, int)> TestData = new TheoryData<(int, int)>();
+				public class TestClass {
+					public static TheoryData<(int, int)> TestData = new TheoryData<(int, int)>();
 
-    [MemberData(nameof(TestData))]
-    public void TestMethod((int a, int b) x) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void TestMethod((int a, int b) x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -1457,16 +1342,17 @@ public void TestMethod((int a, int b) x) { }
 		[Fact]
 		public async Task WhenPassingTupleWithoutFieldNames_TheoryDataRow_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-	public static IList<TheoryDataRow<(int, int)>> TestData = new List<TheoryDataRow<(int, int)>>();
+				public class TestClass {
+					public static IList<TheoryDataRow<(int, int)>> TestData = new List<TheoryDataRow<(int, int)>>();
 
-    [MemberData(nameof(TestData))]
-    public void TestMethod((int a, int b) x) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void TestMethod((int a, int b) x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source);
 		}
@@ -1474,15 +1360,16 @@ public void TestMethod((int a, int b) x) { }
 		[Fact]
 		public async Task WhenPassingTupleWithDifferentFieldNames_TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryData<(int c, int d)> TestData = new TheoryData<(int, int)>();
+				public class TestClass {
+					public static TheoryData<(int c, int d)> TestData = new TheoryData<(int, int)>();
 
-    [MemberData(nameof(TestData))]
-    public void TestMethod((int a, int b) x) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void TestMethod((int a, int b) x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -1490,16 +1377,17 @@ public void TestMethod((int a, int b) x) { }
 		[Fact]
 		public async Task WhenPassingTupleWithDifferentFieldNames_TheoryDataRow_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-	public static IEnumerable<TheoryDataRow<(int c, int d)>> TestData = new List<TheoryDataRow<(int, int)>>();
+				public class TestClass {
+					public static IEnumerable<TheoryDataRow<(int c, int d)>> TestData = new List<TheoryDataRow<(int, int)>>();
 
-    [MemberData(nameof(TestData))]
-    public void TestMethod((int a, int b) x) { }
-}";
+				    [MemberData(nameof(TestData))]
+				    public void TestMethod((int a, int b) x) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source);
 		}
@@ -1507,22 +1395,17 @@ public void TestMethod((int a, int b) x) { }
 		[Fact]
 		public async Task WithExtraValueNotCompatibleWithParamsArray_TheoryData_Triggers()
 		{
-			var source = @"
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {
-	public static TheoryData<int, string, int> TestData = new TheoryData<int, string, int>();
+				public class TestClass {
+					public static TheoryData<int, string, int> TestData = new TheoryData<int, string, int>();
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(8, 42, 8, 50)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("int", "TestClass.TestData", "_2");
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params {|#0:string[]|} _2) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1039").WithLocation(0).WithArguments("int", "TestClass.TestData", "_2");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1530,23 +1413,18 @@ public void PuzzleOne(int _1, params string[] _2) { }
 		[Fact]
 		public async Task WithExtraValueNotCompatibleWithParamsArray_TheoryDataRow_Triggers()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-	public static IEnumerable<TheoryDataRow<int, string, int>> TestData = new List<TheoryDataRow<int, string, int>>();
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-    [MemberData(nameof(TestData))]
-    public void PuzzleOne(int _1, params string[] _2) { }
-}";
+				public class TestClass {
+					public static IEnumerable<TheoryDataRow<int, string, int>> TestData = new List<TheoryDataRow<int, string, int>>();
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(9, 42, 9, 50)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments("int", "TestClass.TestData", "_2");
+				    [MemberData(nameof(TestData))]
+				    public void PuzzleOne(int _1, params {|#0:string[]|} _2) { }
+				}
+				""";
+			var expected = Verify.Diagnostic("xUnit1039").WithLocation(0).WithArguments("int", "TestClass.TestData", "_2");
 
 			await Verify.VerifyAnalyzerV3(source, expected);
 		}
@@ -1557,22 +1435,17 @@ public async Task ValidTheoryDataMemberWithIncompatibleTypeParameters_Triggers(
 			(string syntax, string args) member,
 			string type)
 		{
-			var source = $@"
-using Xunit;
-
-public class TestClass {{
-    public static TheoryData<{type}> TestData{member.syntax}new TheoryData<{type}>();
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(string f) {{ }}
-}}";
+				public class TestClass {{
+				    public static TheoryData<{2}> TestData{0}new TheoryData<{2}>();
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(8, 28, 8, 34)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments(type, "TestClass.TestData", "f");
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod({{|#0:string|}} f) {{ }}
+				}}
+				""", member.syntax, member.args, type);
+			var expected = Verify.Diagnostic("xUnit1039").WithLocation(0).WithArguments(type, "TestClass.TestData", "f");
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
@@ -1583,23 +1456,18 @@ public async Task ValidTheoryDataRowMemberWithIncompatibleTypeParameters_Trigger
 			(string syntax, string args) member,
 			string type)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {{
-    public static IList<TheoryDataRow<{type}>> TestData{member.syntax}new List<TheoryDataRow<{type}>>();
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-    [MemberData(nameof(TestData){member.args})]
-    public void TestMethod(string f) {{ }}
-}}";
+				public class TestClass {{
+				    public static IList<TheoryDataRow<{2}>> TestData{0}new List<TheoryDataRow<{2}>>();
 
-			var expected =
-				Verify
-					.Diagnostic("xUnit1039")
-					.WithSpan(9, 28, 9, 34)
-					.WithSeverity(DiagnosticSeverity.Error)
-					.WithArguments(type, "TestClass.TestData", "f");
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod({{|#0:string|}} f) {{ }}
+				}}
+				""", member.syntax, member.args, type);
+			var expected = Verify.Diagnostic("xUnit1039").WithLocation(0).WithArguments(type, "TestClass.TestData", "f");
 
 			await Verify.VerifyAnalyzerV3(source, expected);
 		}
@@ -1609,10 +1477,10 @@ public class X1040_TheoryDataTypeArgumentsMustMatchTestMethodParameters_Incompat
 	{
 		public static TheoryData<string, string> MemberSyntaxAndArgs = new()
 		{
-			{ " = ", "" },              // Field
-			{ " => ", "" },             // Property
-			{ "() => ", "" },           // Method w/o args
-			{ "(int n) => ", ", 42" },  // Method w/ args
+			/* lang=c#-test */ { " = ", "" },              // Field
+			/* lang=c#-test */ { " => ", "" },             // Property
+			/* lang=c#-test */ { "() => ", "" },           // Method w/o args
+			/* lang=c#-test */ { "(int n) => ", ", 42" },  // Method w/ args
 		};
 
 		[Theory]
@@ -1621,24 +1489,19 @@ public async Task ValidTheoryDataMemberWithMismatchedNullability_Triggers(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-#nullable enable
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
 
-using Xunit;
+				using Xunit;
 
-public class TestClass {{
-    public static TheoryData<string?> TestData{memberSyntax}new TheoryData<string?>();
+				public class TestClass {{
+				    public static TheoryData<string?> TestData{0}new TheoryData<string?>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(string f) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1040")
-					.WithSpan(10, 28, 10, 34)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("string?", "TestClass.TestData", "f");
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod({{|#0:string|}} f) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1040").WithLocation(0).WithArguments("string?", "TestClass.TestData", "f");
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
@@ -1649,25 +1512,20 @@ public async Task ValidTheoryDataRowMemberWithMismatchedNullability_Triggers(
 			string memberSyntax,
 			string memberArgs)
 		{
-			var source = $@"
-#nullable enable
+			var source = string.Format(/* lang=c#-test */ """
+				#nullable enable
 
-using System.Collections.Generic;
-using Xunit;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    public static IEnumerable<TheoryDataRow<string?>> TestData{memberSyntax}new List<TheoryDataRow<string?>>();
+				public class TestClass {{
+				    public static IEnumerable<TheoryDataRow<string?>> TestData{0}new List<TheoryDataRow<string?>>();
 
-    [MemberData(nameof(TestData){memberArgs})]
-    public void TestMethod(string f) {{ }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit1040")
-					.WithSpan(11, 28, 11, 34)
-					.WithSeverity(DiagnosticSeverity.Warning)
-					.WithArguments("string?", "TestClass.TestData", "f");
+				    [MemberData(nameof(TestData){1})]
+				    public void TestMethod({{|#0:string|}} f) {{ }}
+				}}
+				""", memberSyntax, memberArgs);
+			var expected = Verify.Diagnostic("xUnit1040").WithLocation(0).WithArguments("string?", "TestClass.TestData", "f");
 
 			await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source, expected);
 		}
@@ -1678,16 +1536,17 @@ public class X1042_MemberDataTheoryDataIsRecommendedForStronglyTypedAnalysis
 		[Fact]
 		public async Task TheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> Data;
+				public class TestClass {
+				    public static TheoryData<int> Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) { }
-}";
+				    [MemberData(nameof(Data))]
+				    public void TestMethod(int _) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -1695,38 +1554,40 @@ public void TestMethod(int _) { }
 		[Fact]
 		public async Task MatrixTheoryData_DoesNotTrigger()
 		{
-			var source = @"
-using System.Collections.Generic;
-using Xunit;
+			var source = /* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {
-    public static MatrixTheoryData<int, string> Data;
+				public class TestClass {
+				    public static MatrixTheoryData<int, string> Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _1, string _2) { }
-}";
+				    [MemberData(nameof(Data))]
+				    public void TestMethod(int _1, string _2) { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
 
 		[Theory]
-		[InlineData("IEnumerable<TheoryDataRow<int>>")]
-		[InlineData("IAsyncEnumerable<TheoryDataRow<int>>")]
-		[InlineData("List<TheoryDataRow<int>>")]
-		[InlineData("TheoryDataRow<int>[]")]
+		[InlineData(/* lang=c#-test */ "IEnumerable<TheoryDataRow<int>>")]
+		[InlineData(/* lang=c#-test */ "IAsyncEnumerable<TheoryDataRow<int>>")]
+		[InlineData(/* lang=c#-test */ "List<TheoryDataRow<int>>")]
+		[InlineData(/* lang=c#-test */ "TheoryDataRow<int>[]")]
 		public async Task GenericTheoryDataRow_DoesNotTrigger(string memberType)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
-using Xunit.v3;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
+				using Xunit.v3;
 
-public class TestClass {{
-    public static {memberType} Data;
+				public class TestClass {{
+				    public static {0} Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}";
+				    [MemberData(nameof(Data))]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", memberType);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -1736,29 +1597,19 @@ public void TestMethod(int _) {{ }}
 		[InlineData("List<object[]>")]
 		public async Task ValidTypesWhichAreNotTheoryData_Trigger(string memberType)
 		{
-			var source = $@"
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections.Generic;
+				using Xunit;
+
+				public class TestClass {{
+				    public static {0} Data;
 
-public class TestClass {{
-    public static {memberType} Data;
-
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}";
-
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1042")
-					.WithSpan(8, 6, 8, 30)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments("TheoryData<>");
-			var expectedV3 =
-				Verify
-					.Diagnostic("xUnit1042")
-					.WithSpan(8, 6, 8, 30)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments("TheoryData<> or IEnumerable<TheoryDataRow<>>");
+				    [{{|#0:MemberData(nameof(Data))|}}]
+				    public void TestMethod(int _) {{ }}
+				}}
+				""", memberType);
+			var expectedV2 = Verify.Diagnostic("xUnit1042").WithLocation(0).WithArguments("TheoryData<>");
+			var expectedV3 = Verify.Diagnostic("xUnit1042").WithLocation(0).WithArguments("TheoryData<> or IEnumerable<TheoryDataRow<>>");
 
 			await Verify.VerifyAnalyzerV2(source, expectedV2);
 			await Verify.VerifyAnalyzerV3(source, expectedV3);
@@ -1767,47 +1618,41 @@ public void TestMethod(int _) {{ }}
 		// For v2, we test for xUnit1019 above, since it's incompatible rather than "compatible,
 		// but you could do better".
 		[Theory]
-		[InlineData("IAsyncEnumerable<object[]>")]
-		[InlineData("Task<IEnumerable<object[]>>")]
-		[InlineData("ValueTask<List<object[]>>")]
-		[InlineData("IEnumerable<TheoryDataRow>")]
-		[InlineData("IAsyncEnumerable<TheoryDataRow>")]
-		[InlineData("Task<IEnumerable<TheoryDataRow>>")]
-		[InlineData("Task<IAsyncEnumerable<TheoryDataRow>>")]
-		[InlineData("ValueTask<List<TheoryDataRow>>")]
-		[InlineData("IEnumerable<ITheoryDataRow>")]
-		[InlineData("Task<IEnumerable<ITheoryDataRow>>")]
-		[InlineData("Task<IAsyncEnumerable<ITheoryDataRow>>")]
-		[InlineData("ValueTask<EnumerableOfITheoryDataRow>")]
+		[InlineData(/* lang=c#-test */ "IAsyncEnumerable<object[]>")]
+		[InlineData(/* lang=c#-test */ "Task<IEnumerable<object[]>>")]
+		[InlineData(/* lang=c#-test */ "ValueTask<List<object[]>>")]
+		[InlineData(/* lang=c#-test */ "IEnumerable<TheoryDataRow>")]
+		[InlineData(/* lang=c#-test */ "IAsyncEnumerable<TheoryDataRow>")]
+		[InlineData(/* lang=c#-test */ "Task<IEnumerable<TheoryDataRow>>")]
+		[InlineData(/* lang=c#-test */ "Task<IAsyncEnumerable<TheoryDataRow>>")]
+		[InlineData(/* lang=c#-test */ "ValueTask<List<TheoryDataRow>>")]
+		[InlineData(/* lang=c#-test */ "IEnumerable<ITheoryDataRow>")]
+		[InlineData(/* lang=c#-test */ "Task<IEnumerable<ITheoryDataRow>>")]
+		[InlineData(/* lang=c#-test */ "Task<IAsyncEnumerable<ITheoryDataRow>>")]
+		[InlineData(/* lang=c#-test */ "ValueTask<EnumerableOfITheoryDataRow>")]
 		public async Task ValidTypesWhichAreNotTheoryDataOrGenericTheoryDataRow_TriggersInV3(string memberType)
 		{
-			var source = $@"
-using System.Collections;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System.Collections;
+				using System.Collections.Generic;
+				using System.Threading.Tasks;
+				using Xunit;
 
-public class TestClass {{
-    public static {memberType} Data;
+				public class TestClass {{
+				    public static {0} Data;
 
-    [MemberData(nameof(Data))]
-    public void TestMethod(int _) {{ }}
-}}
+				    [{{|#0:MemberData(nameof(Data))|}}]
+				    public void TestMethod(int _) {{ }}
+				}}
 
-public class EnumerableOfITheoryDataRow : IEnumerable<ITheoryDataRow>
-{{
-    public IEnumerator<ITheoryDataRow> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}}";
+				public class EnumerableOfITheoryDataRow : IEnumerable<ITheoryDataRow> {{
+				    public IEnumerator<ITheoryDataRow> GetEnumerator() => null;
+				    IEnumerator IEnumerable.GetEnumerator() => null;
+				}}
+				""", memberType);
+			var expected = Verify.Diagnostic("xUnit1042").WithLocation(0).WithArguments("TheoryData<> or IEnumerable<TheoryDataRow<>>");
 
-			var expectedV2 =
-				Verify
-					.Diagnostic("xUnit1042")
-					.WithSpan(10, 6, 10, 30)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments("TheoryData<> or IEnumerable<TheoryDataRow<>>");
-
-			await Verify.VerifyAnalyzerV3(source, expectedV2);
+			await Verify.VerifyAnalyzerV3(source, expected);
 		}
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/PublicMethodShouldBeMarkedAsTestTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/PublicMethodShouldBeMarkedAsTestTests.cs
index bdd29f64..3fbfa4d1 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/PublicMethodShouldBeMarkedAsTestTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/PublicMethodShouldBeMarkedAsTestTests.cs
@@ -1,307 +1,310 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.PublicMethodShouldBeMarkedAsTest>;
 
 public class PublicMethodShouldBeMarkedAsTestTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForPublicMethodInNonTestClass()
+	public async Task PublicMethodInNonTestClass_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
-	[InlineData("Xunit.Fact")]
-	[InlineData("Xunit.Theory")]
-	public async Task DoesNotFindErrorForTestMethods(string attribute)
+	[InlineData(/* lang=c#-test */ "Xunit.Fact")]
+	[InlineData(/* lang=c#-test */ "Xunit.Theory")]
+	public async Task TestMethods_DoesNotTrigger(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIDisposableDisposeMethod()
+	public async Task IDisposableDisposeMethod_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass: System.IDisposable {
-    [Xunit.Fact]
-    public void TestMethod() { }
+		var source = /* lang=c#-test */ """
+			public class TestClass: System.IDisposable {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    public void Dispose() { }
-}";
+			    public void Dispose() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForPublicAbstractMethod()
+	public async Task PublicAbstractMethod_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+		var source = /* lang=c#-test */ """
+			public abstract class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    public abstract void AbstractMethod();
-}";
+			    public abstract void AbstractMethod();
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForDerivedMethodWithFactOnBaseAbstractMethod()
+	public async Task DerivedMethodWithFactOnBaseAbstractMethod_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class BaseClass {
-    [Xunit.Fact]
-    public abstract void TestMethod();
-}
+		var source = /* lang=c#-test */ """
+			public abstract class BaseClass {
+			    [Xunit.Fact]
+			    public abstract void TestMethod();
+			}
 
-public class TestClass : BaseClass {
-    public override void TestMethod() { }
+			public class TestClass : BaseClass {
+			    public override void TestMethod() { }
 
-    [Xunit.Fact]
-    public void TestMethod2() { }
-}";
+			    [Xunit.Fact]
+			    public void TestMethod2() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForPublicAbstractMethodMarkedWithFact()
+	public async Task PublicAbstractMethodMarkedWithFact_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+		var source = /* lang=c#-test */ """
+			public abstract class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    [Xunit.Fact]
-    public abstract void AbstractMethod();
-}";
+			    [Xunit.Fact]
+			    public abstract void AbstractMethod();
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIDisposableDisposeMethodOverrideFromParentClass()
+	public async Task IDisposableDisposeMethodOverrideFromParentClass_DoesNotTrigger()
 	{
-		var source = @"
-public class BaseClass: System.IDisposable {
-    public virtual void Dispose() { }
-}
+		var source = /* lang=c#-test */ """
+			public class BaseClass: System.IDisposable {
+			    public virtual void Dispose() { }
+			}
 
-public class TestClass: BaseClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+			public class TestClass: BaseClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    public override void Dispose() { }
-}";
+			    public override void Dispose() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIDisposableDisposeMethodOverrideFromParentClassWithRepeatedInterfaceDeclaration()
+	public async Task IDisposableDisposeMethodOverrideFromParentClassWithRepeatedInterfaceDeclaration_DoesNotTrigger()
 	{
-		var source = @"
-public class BaseClass: System.IDisposable {
-    public virtual void Dispose() { }
-}
+		var source = /* lang=c#-test */ """
+			public class BaseClass: System.IDisposable {
+			    public virtual void Dispose() { }
+			}
 
-public class TestClass: BaseClass, System.IDisposable {
-    [Xunit.Fact]
-    public void TestMethod() { }
+			public class TestClass: BaseClass, System.IDisposable {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    public override void Dispose() { }
-}";
+			    public override void Dispose() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIDisposableDisposeMethodOverrideFromGrandParentClass()
+	public async Task IDisposableDisposeMethodOverrideFromGrandParentClass_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class BaseClass: System.IDisposable {
-    public abstract void Dispose();
-}
+		var source = /* lang=c#-test */ """
+			public abstract class BaseClass: System.IDisposable {
+			    public abstract void Dispose();
+			}
 
-public abstract class IntermediateClass: BaseClass { }
+			public abstract class IntermediateClass: BaseClass { }
 
-public class TestClass: IntermediateClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+			public class TestClass: IntermediateClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    public override void Dispose() { }
-}";
+			    public override void Dispose() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIAsyncLifetimeMethods_V2()
+	public async Task IAsyncLifetimeMethods_V2_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass: Xunit.IAsyncLifetime {
-    [Xunit.Fact]
-    public void TestMethod() { }
-
-    public System.Threading.Tasks.Task DisposeAsync()
-    {
-        throw new System.NotImplementedException();
-    }
-
-    public System.Threading.Tasks.Task InitializeAsync()
-    {
-        throw new System.NotImplementedException();
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass: Xunit.IAsyncLifetime {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+
+			    public System.Threading.Tasks.Task DisposeAsync()
+			    {
+			        throw new System.NotImplementedException();
+			    }
+
+			    public System.Threading.Tasks.Task InitializeAsync()
+			    {
+			        throw new System.NotImplementedException();
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV2(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForIAsyncLifetimeMethods_V3()
+	public async Task IAsyncLifetimeMethods_V3_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass: Xunit.IAsyncLifetime {
-    [Xunit.Fact]
-    public void TestMethod() { }
-
-    public System.Threading.Tasks.ValueTask DisposeAsync()
-    {
-        throw new System.NotImplementedException();
-    }
-
-    public System.Threading.Tasks.ValueTask InitializeAsync()
-    {
-        throw new System.NotImplementedException();
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass: Xunit.IAsyncLifetime {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+
+			    public System.Threading.Tasks.ValueTask DisposeAsync()
+			    {
+			        throw new System.NotImplementedException();
+			    }
+
+			    public System.Threading.Tasks.ValueTask InitializeAsync()
+			    {
+			        throw new System.NotImplementedException();
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV3(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForPublicMethodMarkedWithAttributeWhichIsMarkedWithIgnoreXunitAnalyzersRule1013()
+	public async Task PublicMethodMarkedWithAttributeWhichIsMarkedWithIgnoreXunitAnalyzersRule1013_DoesNotTrigger()
 	{
-		var source = @"
-public class IgnoreXunitAnalyzersRule1013Attribute: System.Attribute { }
+		var source = /* lang=c#-test */ """
+			public class IgnoreXunitAnalyzersRule1013Attribute: System.Attribute { }
 
-[IgnoreXunitAnalyzersRule1013]
-public class CustomTestTypeAttribute: System.Attribute { }
+			[IgnoreXunitAnalyzersRule1013]
+			public class CustomTestTypeAttribute: System.Attribute { }
 
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    [CustomTestType]
-    public void CustomTestMethod() { }
-}";
+			    [CustomTestType]
+			    public void CustomTestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsWarningForPublicMethodMarkedWithAttributeWhichInheritsFromAttributeMarkedWithIgnoreXunitAnalyzersRule1013()
+	public async Task PublicMethodMarkedWithAttributeWhichInheritsFromAttributeMarkedWithIgnoreXunitAnalyzersRule1013_Triggers()
 	{
-		var source = @"
-public class IgnoreXunitAnalyzersRule1013Attribute: System.Attribute { }
+		var source = /* lang=c#-test */ """
+			public class IgnoreXunitAnalyzersRule1013Attribute: System.Attribute { }
 
-[IgnoreXunitAnalyzersRule1013]
-public class BaseCustomTestTypeAttribute: System.Attribute { }
+			[IgnoreXunitAnalyzersRule1013]
+			public class BaseCustomTestTypeAttribute: System.Attribute { }
 
-public class DerivedCustomTestTypeAttribute: BaseCustomTestTypeAttribute { }
+			public class DerivedCustomTestTypeAttribute: BaseCustomTestTypeAttribute { }
 
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
 
-    [DerivedCustomTestType]
-    public void CustomTestMethod() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(14, 17, 14, 33)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("CustomTestMethod", "TestClass", "Fact");
+			    [DerivedCustomTestType]
+			    public void {|#0:CustomTestMethod|}() { }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("CustomTestMethod", "TestClass", "Fact");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
-	[InlineData("Xunit.Fact")]
-	[InlineData("Xunit.Theory")]
-	public async Task FindsWarningForPublicMethodWithoutParametersInTestClass(string attribute)
+	[InlineData(/* lang=c#-test */ "Xunit.Fact")]
+	[InlineData(/* lang=c#-test */ "Xunit.Theory")]
+	public async Task PublicMethodWithoutParametersInTestClass_Triggers(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-
-    public void Method() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 17, 6, 23)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Method", "TestClass", "Fact");
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+
+			    public void {{|#0:Method|}}() {{ }}
+			}}
+			""", attribute);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Method", "TestClass", "Fact");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
-	[InlineData("Xunit.Fact")]
-	[InlineData("Xunit.Theory")]
-	public async Task FindsWarningForPublicMethodWithParametersInTestClass(string attribute)
+	[InlineData(/* lang=c#-test */ "Xunit.Fact")]
+	[InlineData(/* lang=c#-test */ "Xunit.Theory")]
+	public async Task PublicMethodWithParametersInTestClass_Triggers(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-
-    public void Method(int a) {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 17, 6, 23)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Method", "TestClass", "Theory");
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+
+			    public void {{|#0:Method|}}(int a) {{ }}
+			}}
+			""", attribute);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Method", "TestClass", "Theory");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
-	[InlineData("Xunit.Fact")]
-	[InlineData("Xunit.Theory")]
-	public async Task DoesNotFindErrorForOverridenMethod(string attribute)
+	[InlineData(/* lang=c#-test */ "Fact")]
+	[InlineData(/* lang=c#-test */ "Theory")]
+	public async Task OverridenMethod_FromParentNonTestClass_DoesNotTrigger(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-
-    public override void Method() {{ }}
-}}";
-		var expected =
-			Verify
-				.CompilerError("CS0115")
-				.WithSpan(6, 26, 6, 32)
-				.WithMessage("'TestClass.Method()': no suitable method found to override");
+		var source = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-		await Verify.VerifyAnalyzer(source, expected);
+			public abstract class ParentClass {{
+			    public abstract void ParentMethod();
+			}}
+
+			public class TestClass : ParentClass {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+
+			    public override void ParentMethod() {{ }}
+			
+				public override void {{|CS0115:MissingMethod|}}() {{ }}
+			}}
+			""", attribute);
+
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassCannotBeNestedInGenericClassTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassCannotBeNestedInGenericClassTests.cs
index cdc811a2..00be7a9e 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassCannotBeNestedInGenericClassTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassCannotBeNestedInGenericClassTests.cs
@@ -5,97 +5,77 @@
 public class TestClassCannotBeNestedInGenericClassTests
 {
 	[Fact]
-	public async Task ReportsDiagnostic_WhenTestClassIsNestedInOpenGenericType()
+	public async Task WhenTestClassIsNestedInOpenGenericType_Triggers()
 	{
-		var source = @"
-public abstract class OpenGenericType<T>
-{
-    public class NestedTestClass
-    {
-        [Xunit.Fact]
-        public void TestMethod() { }
-    }
-}";
-
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(4, 18);
+		var source = /* lang=c#-test */ """
+			public abstract class OpenGenericType<T> {
+			    public class [|NestedTestClass|] {
+			        [Xunit.Fact]
+			        public void TestMethod() { }
+			    }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task ReportsDiagnostic_WhenDerivedTestClassIsNestedInOpenGenericType()
+	public async Task WhenDerivedTestClassIsNestedInOpenGenericType_Triggers()
 	{
-		var source = @"
-public abstract class BaseTestClass
-{
-    [Xunit.Fact]
-    public void TestMethod() { }
-}
-
-public abstract class OpenGenericType<T>
-{
-    public class NestedTestClass : BaseTestClass
-    {
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public abstract class BaseTestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
 
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(10, 18);
+			public abstract class OpenGenericType<T> {
+			    public class [|NestedTestClass|] : BaseTestClass { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotReportDiagnostic_WhenTestClassIsNestedInClosedGenericType()
+	public async Task WhenTestClassIsNestedInClosedGenericType_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class OpenGenericType<T>
-{
-}
+		var source = /* lang=c#-test */ """
+			public abstract class OpenGenericType<T> { }
 
-public abstract class ClosedGenericType : OpenGenericType<int>
-{
-    public class NestedTestClass
-    {
-        [Xunit.Fact]
-        public void TestMethod() { }
-    }
-}";
+			public abstract class ClosedGenericType : OpenGenericType<int> {
+			    public class NestedTestClass {
+			        [Xunit.Fact]
+			        public void TestMethod() { }
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotReportDiagnostic_WhenNestedClassIsNotTestClass()
+	public async Task WhenNestedClassIsNotTestClass_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class OpenGenericType<T>
-{
-    public class NestedClass
-    {
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public abstract class OpenGenericType<T> {
+			    public class NestedClass { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotReportDiagnostic_WhenTestClassIsNotNestedInOpenGenericType()
+	public async Task WhenTestClassIsNotNestedInOpenGenericType_DoesNotTrigger()
 	{
-		var source = @"
-public abstract class NonGenericType
-{
-    public class NestedTestClass
-    {
-        [Xunit.Fact]
-        public void TestMethod() { }
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public abstract class NonGenericType {
+			    public class NestedTestClass {
+			        [Xunit.Fact]
+			        public void TestMethod() { }
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassMustBePublicTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassMustBePublicTests.cs
index c7ab515c..8f67c1a6 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassMustBePublicTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassMustBePublicTests.cs
@@ -1,108 +1,105 @@
-using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.TestClassMustBePublic>;
 
 public class TestClassMustBePublicTests
 {
-	public static IEnumerable<object[]> CreateFactsInNonPublicClassCases =
-		from attribute in new[] { "Xunit.Fact", "Xunit.Theory" }
-		from modifier in new[] { "", "internal" }
-		select new[] { attribute, modifier };
+	public static MatrixTheoryData<string, string> CreateFactsInNonPublicClassCases =
+		new(
+			/* lang=c#-test */ ["Xunit.Fact", "Xunit.Theory"],
+			/* lang=c#-test */ ["", "internal"]
+		);
 
 	[Fact]
-	public async Task ForPublicClass_DoesNotFindError()
+	public async Task ForPublicClass_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(CreateFactsInNonPublicClassCases))]
-	public async Task ForFriendOrInternalClass_FindsError(
+	public async Task ForFriendOrInternalClass_Triggers(
 		string attribute,
 		string modifier)
 	{
-		var source = $@"
-{modifier} class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(2, 8 + modifier.Length, 2, 17 + modifier.Length);
+		var source = string.Format(/* lang=c#-test */ """
+			{1} class [|TestClass|] {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute, modifier);
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
-	[InlineData("")]
-	[InlineData("public")]
-	public async Task ForPartialClassInSameFile_WhenClassIsPublic_DoesNotFindError(string modifier)
+	[InlineData(/* lang=c#-test */ "")]
+	[InlineData(/* lang=c#-test */ "public")]
+	public async Task ForPartialClassInSameFile_WhenClassIsPublic_DoesNotTrigger(string modifier)
 	{
-		var source = $@"
-public partial class TestClass {{
-    [Xunit.Fact]
-    public void Test1() {{ }}
-}}
+		var source = string.Format(/* lang=c#-test */ """
+			public partial class TestClass {{
+			    [Xunit.Fact]
+			    public void Test1() {{ }}
+			}}
 
-{modifier} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test2() {{ }}
-}}";
+			{0} partial class TestClass {{
+			    [Xunit.Fact]
+			    public void Test2() {{ }}
+			}}
+			""", modifier);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
-	[InlineData("")]
-	[InlineData("public")]
-	public async Task ForPartialClassInOtherFiles_WhenClassIsPublic_DoesNotFindError(string modifier)
+	[InlineData(/* lang=c#-test */ "")]
+	[InlineData(/* lang=c#-test */ "public")]
+	public async Task ForPartialClassInOtherFiles_WhenClassIsPublic_DoesNotTrigger(string modifier)
 	{
-		var source1 = @"
-public partial class TestClass {
-    [Xunit.Fact]
-    public void Test1() { }
-}";
-		var source2 = $@"
-{modifier} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test2() {{ }}
-}}";
+		var source1 = /* lang=c#-test */ """
+			public partial class TestClass {
+			    [Xunit.Fact]
+			    public void Test1() { }
+			}
+			""";
+		var source2 = string.Format(/* lang=c#-test */ """
+			{0} partial class TestClass {{
+			    [Xunit.Fact]
+			    public void Test2() {{ }}
+			}}
+			""", modifier);
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 });
+		await Verify.VerifyAnalyzer([source1, source2]);
 	}
 
 	[Theory]
 	[InlineData("", "")]
 	[InlineData("", "internal")]
 	[InlineData("internal", "internal")]
-	public async Task ForPartialClassInSameFile_WhenClassIsNonPublic_FindsError(
+	public async Task ForPartialClassInSameFile_WhenClassIsNonPublic_Triggers(
 		string modifier1,
 		string modifier2)
 	{
-		var source = $@"
-{modifier1} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test1() {{ }}
-}}
+		var source = string.Format(/* lang=c#-test */ """
+			{0} partial class {{|#0:TestClass|}} {{
+			    [Xunit.Fact]
+			    public void Test1() {{ }}
+			}}
 
-{modifier2} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test2() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(2, 16 + modifier1.Length, 2, 25 + modifier1.Length)
-				.WithSpan(7, 16 + modifier2.Length, 7, 25 + modifier2.Length);
+			{1} partial class {{|#1:TestClass|}} {{
+			    [Xunit.Fact]
+			    public void Test2() {{ }}
+			}}
+			""", modifier1, modifier2);
+		var expected = Verify.Diagnostic().WithLocation(0).WithLocation(1);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -111,26 +108,24 @@ public void Test2() {{ }}
 	[InlineData("", "")]
 	[InlineData("", "internal")]
 	[InlineData("internal", "internal")]
-	public async Task ForPartialClassInOtherFiles_WhenClassIsNonPublic_FindsError(
+	public async Task ForPartialClassInOtherFiles_WhenClassIsNonPublic_Triggers(
 		string modifier1,
 		string modifier2)
 	{
-		var source1 = $@"
-{modifier1} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test1() {{ }}
-}}";
-		var source2 = $@"
-{modifier2} partial class TestClass {{
-    [Xunit.Fact]
-    public void Test2() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(2, 16 + modifier1.Length, 2, 25 + modifier1.Length)
-				.WithSpan("/0/Test1.cs", 2, 16 + modifier2.Length, 2, 25 + modifier2.Length);
+		var source1 = string.Format(/* lang=c#-test */ """
+			{0} partial class {{|#0:TestClass|}} {{
+			    [Xunit.Fact]
+			    public void Test1() {{ }}
+			}}
+			""", modifier1);
+		var source2 = string.Format(/* lang=c#-test */ """
+			{0} partial class {{|#1:TestClass|}} {{
+			    [Xunit.Fact]
+			    public void Test2() {{ }}
+			}}
+			""", modifier2);
+		var expected = Verify.Diagnostic().WithLocation(0).WithLocation(1);
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+		await Verify.VerifyAnalyzer([source1, source2], expected);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassShouldHaveTFixtureArgumentTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassShouldHaveTFixtureArgumentTests.cs
index ad33f9ac..02e3534b 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestClassShouldHaveTFixtureArgumentTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestClassShouldHaveTFixtureArgumentTests.cs
@@ -1,74 +1,72 @@
-using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.TestClassShouldHaveTFixtureArgument>;
 
 public class TestClassShouldHaveTFixtureArgumentTests
 {
-	public static IEnumerable<object[]> CreateFactsInNonPublicClassCases =
-		from attribute in new[] { "Xunit.Fact", "Xunit.Theory" }
-		from @interface in new[] { "Xunit.IClassFixture", "Xunit.ICollectionFixture" }
-		select new[] { attribute, @interface };
+	public static MatrixTheoryData<string, string> CreateFactsInNonPublicClassCases =
+		new(
+			/* lang=c#-test */ ["Xunit.Fact", "Xunit.Theory"],
+			/* lang=c#-test */ ["Xunit.IClassFixture", "Xunit.ICollectionFixture"]
+		);
 
 	[Theory]
 	[MemberData(nameof(CreateFactsInNonPublicClassCases))]
-	public async Task ForClassWithIClassFixtureWithoutConstructorArg_FindsInfo(
+	public async Task ForClassWithIClassFixtureWithoutConstructorArg_Triggers(
 		string attribute,
 		string @interface)
 	{
-		var source = $@"
-public class FixtureData {{ }}
+		var source = string.Format(/* lang=c#-test */ """
+			public class FixtureData {{ }}
 
-public class TestClass: {@interface}<FixtureData> {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 14, 4, 23)
-				.WithArguments("TestClass", "FixtureData");
+			public class {{|#0:TestClass|}}: {1}<FixtureData> {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute, @interface);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestClass", "FixtureData");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(CreateFactsInNonPublicClassCases))]
-	public async Task ForClassWithIClassFixtureWithConstructorArg_DonnotFindInfo(
+	public async Task ForClassWithIClassFixtureWithConstructorArg_DoesNotTrigger(
 		string attribute,
 		string @interface)
 	{
-		var source = $@"
-public class FixtureData {{ }}
+		var source = string.Format(/* lang=c#-test */ """
+			public class FixtureData {{ }}
 
-public class TestClass: {@interface}<FixtureData> {{
-    public TestClass(FixtureData fixtureData) {{ }}
+			public class TestClass: {1}<FixtureData> {{
+			    public TestClass(FixtureData fixtureData) {{ }}
 
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute, @interface);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(CreateFactsInNonPublicClassCases))]
-	public async Task ForClassWithIClassFixtureWithConstructorMultipleArg_DonnotFindInfo(
+	public async Task ForClassWithIClassFixtureWithConstructorMultipleArg_DoesNotTrigger(
 		string attribute,
 		string @interface)
 	{
-		var source = $@"
-public class FixtureData {{ }}
+		var source = /* lang=c#-test */ """
+			public class FixtureData {{ }}
 
-public class TestClass: {@interface}<FixtureData> {{
-    public TestClass(FixtureData fixtureData, Xunit.Abstractions.ITestOutputHelper output) {{ }}
+			public class TestClass: {1}<FixtureData> {{
+			    public TestClass(FixtureData fixtureData, {2}.ITestOutputHelper output) {{ }}
 
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""";
 
-		// This is a v2-only test because of the use of Xunit.Abstractions.ITestOutputHelper
-		await Verify.VerifyAnalyzerV2(source);
+		await Verify.VerifyAnalyzerV2(string.Format(source, attribute, @interface, "Xunit.Abstractions"));
+		await Verify.VerifyAnalyzerV3(string.Format(source, attribute, @interface, "Xunit"));
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodCannotHaveOverloadsTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodCannotHaveOverloadsTests.cs
index 3697d02b..88776872 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodCannotHaveOverloadsTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodCannotHaveOverloadsTests.cs
@@ -1,135 +1,113 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.TestMethodCannotHaveOverloads>;
 
 public class TestMethodCannotHaveOverloadsTests
 {
 	[Fact]
-	public async Task FindsErrors_ForInstanceMethodOverloads_InSameInstanceClass()
+	public async Task ForInstanceMethodOverloads_InSameInstanceClass_Triggers()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void {|#0:TestMethod|}() { }
 
-    [Xunit.Theory]
-    public void TestMethod(int a) { }
-}";
+			    [Xunit.Theory]
+			    public void {|#1:TestMethod|}(int a) { }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "TestClass"),
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 17, 7, 27)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "TestClass"),
+			Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "TestClass"),
+			Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass", "TestClass"),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsErrors_ForStaticMethodOverloads_InSameStaticClass()
+	public async Task ForStaticMethodOverloads_InSameStaticClass_Triggers()
 	{
-		var source = @"
-public static class TestClass {
-    [Xunit.Fact]
-    public static void TestMethod() { }
+		var source = /* lang=c#-test */ """
+			public static class TestClass {
+			    [Xunit.Fact]
+			    public static void {|#0:TestMethod|}() { }
 
-    [Xunit.Theory]
-    public static void TestMethod(int a) { }
-}";
+			    [Xunit.Theory]
+			    public static void {|#1:TestMethod|}(int a) { }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 24, 4, 34)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "TestClass"),
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 24, 7, 34)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "TestClass"),
+			Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "TestClass"),
+			Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass", "TestClass"),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsErrors_ForInstanceMethodOverload_InDerivedClass()
+	public async Task ForInstanceMethodOverload_InDerivedClass_Triggers()
 	{
-		var source1 = @"
-public class TestClass : BaseClass {
-    [Xunit.Theory]
-    public void TestMethod(int a) { }
+		var source1 = /* lang=c#-test */ """
+			public class TestClass : BaseClass {
+			    [Xunit.Theory]
+			    public void {|#0:TestMethod|}(int a) { }
 
-    private void TestMethod(int a, byte c) { }
-}";
-		var source2 = @"
-public class BaseClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			    private void {|#1:TestMethod|}(int a, byte c) { }
+			}
+			""";
+		var source2 = /* lang=c#-test */ """
+			public class BaseClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "BaseClass"),
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 18, 6, 28)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "BaseClass"),
+			Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "BaseClass"),
+			Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass", "BaseClass"),
 		};
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+		await Verify.VerifyAnalyzer([source1, source2], expected);
 	}
 
 	[Fact]
-	public async Task FindsError_ForStaticAndInstanceMethodOverload()
+	public async Task ForStaticAndInstanceMethodOverload_Triggers()
 	{
-		var source1 = @"
-public class TestClass : BaseClass {
-    [Xunit.Theory]
-    public void TestMethod(int a) { }
-}";
-		var source2 = @"
-public class BaseClass {
-    [Xunit.Fact]
-    public static void TestMethod() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "BaseClass");
+		var source1 = /* lang=c#-test */ """
+			public class TestClass : BaseClass {
+			    [Xunit.Theory]
+			    public void {|#0:TestMethod|}(int a) { }
+			}
+			""";
+		var source2 = /* lang=c#-test */ """
+			public class BaseClass {
+			    [Xunit.Fact]
+			    public static void TestMethod() { }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "BaseClass");
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+		await Verify.VerifyAnalyzer([source1, source2], expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindError_ForMethodOverrides()
+	public async Task ForMethodOverrides_DoesNotTrigger()
 	{
-		var source1 = @"
-public class BaseClass {
-    [Xunit.Fact]
-    public virtual void TestMethod() { }
-}";
-		var source2 = @"
-public class TestClass : BaseClass {
-    [Xunit.Fact]
-    public override void TestMethod() { }
-}";
+		var source1 = /* lang=c#-test */ """
+			public class BaseClass {
+			    [Xunit.Fact]
+			    public virtual void TestMethod() { }
+			}
+			""";
+		var source2 = /* lang=c#-test */ """
+			public class TestClass : BaseClass {
+			    [Xunit.Fact]
+			    public override void TestMethod() { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 });
+		await Verify.VerifyAnalyzer([source1, source2]);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodMustNotHaveMultipleFactAttributesTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodMustNotHaveMultipleFactAttributesTests.cs
index 2a9259fe..03dac6e0 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodMustNotHaveMultipleFactAttributesTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodMustNotHaveMultipleFactAttributesTests.cs
@@ -7,49 +7,46 @@ public class TestMethodMustNotHaveMultipleFactAttributesTests
 	[Theory]
 	[InlineData("Fact")]
 	[InlineData("Theory")]
-	public async Task DoesNotFindErrorForMethodWithSingleAttribute(string attribute)
+	public async Task MethodWithSingleAttribute_DoesNotTrigger(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.{attribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsErrorForMethodWithTheoryAndFact()
+	public async Task MethodWithFactAndTheory_Triggers()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    [Xunit.Theory]
-    public void TestMethod() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 17, 5, 27);
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    [Xunit.Theory]
+			    public void [|TestMethod|]() { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsErrorForMethodWithCustomFactAttribute()
+	public async Task MethodWithFactAndCustomFactAttribute_Triggers()
 	{
-		var source1 = @"
-public class TestClass {
-    [Xunit.Fact]
-    [CustomFact]
-    public void TestMethod() { }
-}";
-		var source2 = "public class CustomFactAttribute : Xunit.FactAttribute { }";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 17, 5, 27);
+		var source1 = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    [CustomFact]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var source2 = /* lang=c#-test */ """
+			public class CustomFactAttribute : Xunit.FactAttribute { }
+			""";
 
-		await Verify.VerifyAnalyzer(new[] { source1, source2 }, expected);
+		await Verify.VerifyAnalyzer([source1, source2]);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodShouldNotBeSkippedTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodShouldNotBeSkippedTests.cs
index 4143b9ef..f2387d6c 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodShouldNotBeSkippedTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodShouldNotBeSkippedTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.TestMethodShouldNotBeSkipped>;
 
@@ -8,13 +7,14 @@ public class TestMethodShouldNotBeSkippedTests
 	[Theory]
 	[InlineData("Fact")]
 	[InlineData("Theory")]
-	public async Task DoesNotFindErrorForNotSkippedTest(string attribute)
+	public async Task NotSkippedTest_DoesNotTrigger(string attribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.{attribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -22,19 +22,15 @@ public void TestMethod() {{ }}
 	[Theory]
 	[InlineData("Fact")]
 	[InlineData("Theory")]
-	public async Task FindsErrorForSkippedTests(string attribute)
+	public async Task SkippedTest_Triggers(string attribute)
 	{
-		var source = $@"
-class TestClass {{
-    [Xunit.{attribute}(Skip=""Lazy"")]
-    public void TestMethod() {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(3, 13 + attribute.Length, 3, 24 + attribute.Length)
-				.WithSeverity(DiagnosticSeverity.Info);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    [Xunit.{0}([|Skip="Lazy"|])]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute);
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodSupportedReturnTypeTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodSupportedReturnTypeTests.cs
index b5a81528..aab31bce 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodSupportedReturnTypeTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TestMethodSupportedReturnTypeTests.cs
@@ -6,96 +6,80 @@
 public class TestMethodSupportedReturnTypeTests
 {
 	[Fact]
-	public async Task NonTestMethod()
+	public async Task NonTestMethod_DoesNotTrigger()
 	{
-		var source = @"
-public class NonTestClass {
-    public int Add(int x, int y) {
-        return x + y;
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public class NonTestClass {
+			    public int Add(int x, int y) {
+			        return x + y;
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
-	[InlineData("int")]
 	[InlineData("object")]
-	public async Task InvalidReturnType(string returnType)
+	[InlineData("Task<int>")]
+	[InlineData("ValueTask<string>")]
+	public async Task InvalidReturnType_Triggers(string returnType)
 	{
-		var sourceTemplate = @"
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public {0} TestMethod() {{
-        return default({0});
-	}}
-}}";
-
-		var source = string.Format(sourceTemplate, returnType);
-
-		// v2
-		var expectedV2 =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 13 + returnType.Length, 6, 23 + returnType.Length)
-				.WithArguments("void, Task");
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {{
+			    [Fact]
+			    public {0} {{|#0:TestMethod|}}() {{
+			        return default({0});
+				}}
+			}}
+			""", returnType);
+		var expectedV2 = Verify.Diagnostic().WithLocation(0).WithArguments("void, Task");
+		var expectedV3 = Verify.Diagnostic().WithLocation(0).WithArguments("void, Task, ValueTask");
 
 		await Verify.VerifyAnalyzerV2(source, expectedV2);
-
-		// v3
-		var expectedV3 =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 13 + returnType.Length, 6, 23 + returnType.Length)
-				.WithArguments("void, Task, ValueTask");
-
 		await Verify.VerifyAnalyzerV3(source, expectedV3);
 	}
 
 	[Fact]
-	public async Task V2DoesNotSupportValueTask()
+	public async Task ValueTask_TriggersInV2_DoesNotTriggerInV3()
 	{
-		var source = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public ValueTask TestMethod() {
-        return default(ValueTask);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public ValueTask {|#0:TestMethod|}() {
+			        return default(ValueTask);
+			    }
+			}
+			""";
+		var expectedV2 = Verify.Diagnostic().WithLocation(0).WithArguments("void, Task");
 
-		var expectedV2 =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 22, 7, 32)
-				.WithArguments("void, Task");
 		await Verify.VerifyAnalyzerV2(LanguageVersion.CSharp7, source, expectedV2);
-
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp7, source);
 	}
 
 	[Theory]
 	[InlineData("MyTest")]
 	[InlineData("MyTestAttribute")]
-	public async Task CustomTestAttribute(string attribute)
+	public async Task CustomTestAttribute_DoesNotTrigger(string attribute)
 	{
-		var sourceTemplate = @"
-using Xunit;
-
-class MyTestAttribute : FactAttribute {{ }}
-
-public class TestClass {{
-    [{0}]
-    public int TestMethod() {{
-        return 0;
-	}}
-}}";
-
-		var source = string.Format(sourceTemplate, attribute);
+		var source = string.Format(/* lang=c#-test */ """
+			using Xunit;
+
+			class MyTestAttribute : FactAttribute {{ }}
+
+			public class TestClass {{
+			    [{0}]
+			    public int TestMethod() {{
+			        return 0;
+				}}
+			}}
+			""", attribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataRowArgumentsShouldBeSerializableTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataRowArgumentsShouldBeSerializableTests.cs
index f2a45714..fba27736 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataRowArgumentsShouldBeSerializableTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataRowArgumentsShouldBeSerializableTests.cs
@@ -8,18 +8,19 @@ public sealed class TheoryDataRowArgumentsShouldBeSerializableTests
 	[Fact]
 	public async Task ParamArrayArguments_NotUsingTheoryDataRow_DoesNotTrigger()
 	{
-		var source = @"
-#nullable enable
+		var source = /* lang=c#-test */ """
+			#nullable enable
 
-public class Foo {
-    public Foo(params object[] args) { }
-}
+			public class Foo {
+			    public Foo(params object[] args) { }
+			}
 
-public class TestClass {
-    public void TestMethod() {
-        var foo = new Foo(new object());
-    }
-}";
+			public class TestClass {
+			    public void TestMethod() {
+			        var foo = new Foo(new object());
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source);
 	}
@@ -54,25 +55,26 @@ public async Task IntrinsicallySerializableValue_DoesNotTrigger(
 		string value,
 		string type)
 	{
-		var source = $@"
-#nullable enable
-
-using System;
-using System.Collections.Generic;
-using System.Numerics;
-using Xunit;
-
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var value = {value};
-        var defaultValue = default({type});
-        var nullValue = default({type}?);
-        var arrayValue = new {type}[0];
-
-        yield return new TheoryDataRow(value, defaultValue, nullValue, arrayValue);
-        yield return new TheoryDataRow<{type}, {type}?, {type}?, {type}[]>({value}, default({type}), default({type}?), new {type}[0]);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
+
+			using System;
+			using System.Collections.Generic;
+			using System.Numerics;
+			using Xunit;
+
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var value = {0};
+			        var defaultValue = default({1});
+			        var nullValue = default({1}?);
+			        var arrayValue = new {1}[0];
+
+			        yield return new TheoryDataRow(value, defaultValue, nullValue, arrayValue);
+			        yield return new TheoryDataRow<{1}, {1}?, {1}?, {1}[]>({0}, default({1}), default({1}?), new {1}[0]);
+			    }}
+			}}
+			""", value, type);
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source);
 	}
@@ -82,36 +84,37 @@ public IEnumerable<TheoryDataRow> MyMethod() {{
 	[InlineData("SerializableStruct")]
 	public async Task IXunitSerializableValue_DoesNotTrigger(string type)
 	{
-		var source = $@"
-#nullable enable
-
-using System.Collections.Generic;
-using Xunit;
-using Xunit.Sdk;
-
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var value = new {type}();
-        var defaultValue = default({type});
-        var nullValue = default({type}?);
-        var arrayValue = new {type}[0];
-
-        yield return new TheoryDataRow(value, defaultValue, nullValue, arrayValue);
-        yield return new TheoryDataRow<{type}, {type}?, {type}?, {type}[]>(new {type}(), default({type}), default({type}?), new {type}[0]);
-    }}
-}}
-
-public interface ISerializableInterface : IXunitSerializable {{ }}
-
-public class SerializableClass : ISerializableInterface {{
-    public void Deserialize(IXunitSerializationInfo info) {{ }}
-    public void Serialize(IXunitSerializationInfo info) {{ }}
-}}
-
-public struct SerializableStruct : ISerializableInterface {{
-    public void Deserialize(IXunitSerializationInfo info) {{ }}
-    public void Serialize(IXunitSerializationInfo info) {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
+
+			using System.Collections.Generic;
+			using Xunit;
+			using Xunit.Sdk;
+
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var value = new {0}();
+			        var defaultValue = default({0});
+			        var nullValue = default({0}?);
+			        var arrayValue = new {0}[0];
+
+			        yield return new TheoryDataRow(value, defaultValue, nullValue, arrayValue);
+			        yield return new TheoryDataRow<{0}, {0}?, {0}?, {0}[]>(new {0}(), default({0}), default({0}?), new {0}[0]);
+			    }}
+			}}
+
+			public interface ISerializableInterface : IXunitSerializable {{ }}
+
+			public class SerializableClass : ISerializableInterface {{
+			    public void Deserialize(IXunitSerializationInfo info) {{ }}
+			    public void Serialize(IXunitSerializationInfo info) {{ }}
+			}}
+
+			public struct SerializableStruct : ISerializableInterface {{
+			    public void Deserialize(IXunitSerializationInfo info) {{ }}
+			    public void Serialize(IXunitSerializationInfo info) {{ }}
+			}}
+			""", type);
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source);
 	}
@@ -126,55 +129,36 @@ public async Task KnownNonSerializableValue_Triggers1046(
 		string defaultValueType,
 		string nullValueType)
 	{
-		var source = $@"
-#nullable enable
-
-using System;
-using System.Collections.Generic;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
 
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var defaultValue = default({type});
-        var nullValue = default({type}?);
-        var arrayValue = new {type}[0];
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-        yield return new TheoryDataRow(defaultValue, nullValue, arrayValue);
-        yield return new TheoryDataRow<{defaultValueType}, {nullValueType}, {type}[]>(default({type}), default({type}?), new {type}[0]);
-    }}
-}}
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var defaultValue = default({0});
+			        var nullValue = default({0}?);
+			        var arrayValue = new {0}[0];
 
-public sealed class NonSerializableSealedClass {{ }}
+			        yield return new TheoryDataRow({{|#0:defaultValue|}}, {{|#1:nullValue|}}, {{|#2:arrayValue|}});
+			        yield return new TheoryDataRow<{1}, {2}, {0}[]>({{|#3:default({0})|}}, {{|#4:default({0}?)|}}, {{|#5:new {0}[0]|}});
+			    }}
+			}}
 
-public struct NonSerializableStruct {{ }}";
+			public sealed class NonSerializableSealedClass {{ }}
 
-		var leftGeneric = 48 + defaultValueType.Length + nullValueType.Length + type.Length;
+			public struct NonSerializableStruct {{ }}
+			""", type, defaultValueType, nullValueType);
 		var expected = new[] {
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(14, 40, 14, 52)
-					.WithArguments("defaultValue", defaultValueType),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(14, 54, 14, 63)
-					.WithArguments("nullValue", nullValueType),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(14, 65, 14, 75)
-					.WithArguments("arrayValue", $"{type}[]"),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(15, leftGeneric, 15, leftGeneric + 9 + type.Length)  // +9 for "default()"
-					.WithArguments($"default({type})", defaultValueType),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(15, leftGeneric + 11 + type.Length, 15, leftGeneric + 21 + type.Length * 2)  // +10 for "default(?)"
-					.WithArguments($"default({type}?)", nullValueType),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(15, leftGeneric + 23 + type.Length * 2, 15, leftGeneric + 30 + type.Length * 3)  // +7 for "new [0]"
-					.WithArguments($"new {type}[0]", $"{type}[]"),
-			};
+			Verify.Diagnostic("xUnit1046").WithLocation(0).WithArguments("defaultValue", defaultValueType),
+			Verify.Diagnostic("xUnit1046").WithLocation(1).WithArguments("nullValue", nullValueType),
+			Verify.Diagnostic("xUnit1046").WithLocation(2).WithArguments("arrayValue", $"{type}[]"),
+			Verify.Diagnostic("xUnit1046").WithLocation(3).WithArguments($"default({type})", defaultValueType),
+			Verify.Diagnostic("xUnit1046").WithLocation(4).WithArguments($"default({type}?)", nullValueType),
+			Verify.Diagnostic("xUnit1046").WithLocation(5).WithArguments($"new {type}[0]", $"{type}[]"),
+		};
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source, expected);
 	}
@@ -184,45 +168,33 @@ public struct NonSerializableStruct {{ }}";
 	[InlineData("NonSerializableStruct")]
 	public async Task KnownNonSerializableValue_Constructable_Triggers1046(string type)
 	{
-		var source = $@"
-#nullable enable
-
-using System.Collections.Generic;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
 
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var value = new {type}();
+			using System.Collections.Generic;
+			using Xunit;
 
-        yield return new TheoryDataRow(value);
-        yield return new TheoryDataRow(new {type}());
-        yield return new TheoryDataRow<{type}>(value);
-        yield return new TheoryDataRow<{type}>(new {type}());
-    }}
-}}
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var value = new {0}();
 
-public sealed class NonSerializableSealedClass {{ }}
+			        yield return new TheoryDataRow({{|#0:value|}});
+			        yield return new TheoryDataRow({{|#1:new {0}()|}});
+			        yield return new TheoryDataRow<{0}>({{|#2:value|}});
+			        yield return new TheoryDataRow<{0}>({{|#3:new {0}()|}});
+			    }}
+			}}
 
-public struct NonSerializableStruct {{ }}";
+			public sealed class NonSerializableSealedClass {{ }}
 
+			public struct NonSerializableStruct {{ }}
+			""", type);
 		var expected = new[] {
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(11, 40, 11, 45)
-					.WithArguments("value", type),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(12, 40, 12, 46 + type.Length)
-					.WithArguments($"new {type}()", type),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(13, 42 + type.Length, 13, 47 + type.Length)
-					.WithArguments("value", type),
-				Verify
-					.Diagnostic("xUnit1046")
-					.WithSpan(14, 42 + type.Length, 14, 48 + type.Length * 2)
-					.WithArguments($"new {type}()", type),
-			};
+			Verify.Diagnostic("xUnit1046").WithLocation(0).WithArguments("value", type),
+			Verify.Diagnostic("xUnit1046").WithLocation(1).WithArguments($"new {type}()", type),
+			Verify.Diagnostic("xUnit1046").WithLocation(2).WithArguments("value", type),
+			Verify.Diagnostic("xUnit1046").WithLocation(3).WithArguments($"new {type}()", type),
+		};
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source, expected);
 	}
@@ -238,55 +210,36 @@ public struct NonSerializableStruct {{ }}";
 	[InlineData("PossiblySerializableUnsealedClass")]
 	public async Task MaybeNonSerializableValue_Triggers1047(string type)
 	{
-		var source = $@"
-#nullable enable
-
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
 
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var defaultValue = default({type});
-        var nullValue = default({type}?);
-        var arrayValue = new {type}[0];
+			using System;
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
 
-        yield return new TheoryDataRow(defaultValue, nullValue, arrayValue);
-        yield return new TheoryDataRow<{type}, {type}, {type}[]>(default({type}), default({type}?), new {type}[0]);
-    }}
-}}
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var defaultValue = default({0});
+			        var nullValue = default({0}?);
+			        var arrayValue = new {0}[0];
 
-public interface IPossiblySerializableInterface {{ }}
+			        yield return new TheoryDataRow({{|#0:defaultValue|}}, {{|#1:nullValue|}}, {{|#2:arrayValue|}});
+			        yield return new TheoryDataRow<{0}, {0}, {0}[]>({{|#3:default({0})|}}, {{|#4:default({0}?)|}}, {{|#5:new {0}[0]|}});
+			    }}
+			}}
 
-public class PossiblySerializableUnsealedClass {{ }}";
+			public interface IPossiblySerializableInterface {{ }}
 
-		var leftGeneric = 48 + type.Length * 3;
+			public class PossiblySerializableUnsealedClass {{ }}
+			""", type);
 		var expected = new[] {
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(15, 40, 15, 52)
-				.WithArguments("defaultValue", $"{type}?"),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(15, 54, 15, 63)
-				.WithArguments("nullValue", $"{type}?"),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(15, 65, 15, 75)
-				.WithArguments("arrayValue", $"{type}[]"),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(16, leftGeneric, 16, leftGeneric + 9 + type.Length)  // +9 for "default()"
-				.WithArguments($"default({type})", $"{type}?"),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(16, leftGeneric + 11 + type.Length, 16, leftGeneric + 21 + type.Length * 2)  // +10 for "default(?)"
-				.WithArguments($"default({type}?)", $"{type}?"),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(16, leftGeneric + 23 + type.Length * 2, 16, leftGeneric + 30 + type.Length * 3)  // +7 for "new [0]"
-				.WithArguments($"new {type}[0]", $"{type}[]"),
+			Verify.Diagnostic("xUnit1047").WithLocation(0).WithArguments("defaultValue", $"{type}?"),
+			Verify.Diagnostic("xUnit1047").WithLocation(1).WithArguments("nullValue", $"{type}?"),
+			Verify.Diagnostic("xUnit1047").WithLocation(2).WithArguments("arrayValue", $"{type}[]"),
+			Verify.Diagnostic("xUnit1047").WithLocation(3).WithArguments($"default({type})", $"{type}?"),
+			Verify.Diagnostic("xUnit1047").WithLocation(4).WithArguments($"default({type}?)", $"{type}?"),
+			Verify.Diagnostic("xUnit1047").WithLocation(5).WithArguments($"new {type}[0]", $"{type}[]"),
 		};
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source, expected);
@@ -298,42 +251,30 @@ public class PossiblySerializableUnsealedClass {{ }}";
 	[InlineData("PossiblySerializableUnsealedClass")]
 	public async Task MaybeNonSerializableValue_Constructable_Triggers1047(string type)
 	{
-		var source = $@"
-#nullable enable
-
-using System.Collections.Generic;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			#nullable enable
 
-public class MyClass {{
-    public IEnumerable<TheoryDataRow> MyMethod() {{
-        var value = new {type}();
+			using System.Collections.Generic;
+			using Xunit;
 
-        yield return new TheoryDataRow(value);
-        yield return new TheoryDataRow(new {type}());
-        yield return new TheoryDataRow<{type}>(value);
-        yield return new TheoryDataRow<{type}>(new {type}());
-    }}
-}}
+			public class MyClass {{
+			    public IEnumerable<TheoryDataRow> MyMethod() {{
+			        var value = new {0}();
 
-public class PossiblySerializableUnsealedClass {{ }}";
+			        yield return new TheoryDataRow({{|#0:value|}});
+			        yield return new TheoryDataRow({{|#1:new {0}()|}});
+			        yield return new TheoryDataRow<{0}>({{|#2:value|}});
+			        yield return new TheoryDataRow<{0}>({{|#3:new {0}()|}});
+			    }}
+			}}
 
+			public class PossiblySerializableUnsealedClass {{ }}
+			""", type);
 		var expected = new[] {
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(11, 40, 11, 45)
-				.WithArguments("value", type),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(12, 40, 12, 46 + type.Length)
-				.WithArguments($"new {type}()", type),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(13, 42 + type.Length, 13, 47 + type.Length)
-				.WithArguments("value", type),
-			Verify
-				.Diagnostic("xUnit1047")
-				.WithSpan(14, 42 + type.Length, 14, 48 + type.Length * 2)
-				.WithArguments($"new {type}()", type),
+			Verify.Diagnostic("xUnit1047").WithLocation(0).WithArguments("value", type),
+			Verify.Diagnostic("xUnit1047").WithLocation(1).WithArguments($"new {type}()", type),
+			Verify.Diagnostic("xUnit1047").WithLocation(2).WithArguments("value", type),
+			Verify.Diagnostic("xUnit1047").WithLocation(3).WithArguments($"new {type}()", type),
 		};
 
 		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp8, source, expected);
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializableTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializableTests.cs
index b74b418f..61f164d7 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializableTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializableTests.cs
@@ -16,19 +16,20 @@ public static TheoryData<string, string, string, string> TheoryDataClass(
 		string type2,
 		string type3)
 	{
-		var source = $@"
-using System;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-public class TestClass {{
-    [{theoryAttribute}]
-    [ClassData(typeof(DerivedClass))]
-    public void TestMethod({type1} a, {type2} b, {type3} c) {{ }}
-}}
+			public class TestClass {{
+			    [{0}]
+			    [ClassData(typeof(DerivedClass))]
+			    public void TestMethod({1} a, {2} b, {3} c) {{ }}
+			}}
 
-public class BaseClass<T1, T2, T3, T4> : TheoryData<T1, T2, {type3}> {{ }}
+			public class BaseClass<T1, T2, T3, T4> : TheoryData<T1, T2, {3}> {{ }}
 
-public class DerivedClass : BaseClass<{type1}, {type2}, object, Delegate> {{ }}";
+			public class DerivedClass : BaseClass<{1}, {2}, object, Delegate> {{ }}
+			""", theoryAttribute, type1, type2, type3);
 
 		return new TheoryData<string, string, string, string>
 		{
@@ -38,82 +39,85 @@ public class DerivedClass : BaseClass<{type1}, {type2}, object, Delegate> {{ }}"
 
 	public static TheoryData<string, string, string> TheoryDataMembers(string type)
 	{
-		var @class = $@"public sealed class Class : TheoryData<{type}> {{ }}";
-		var field = $@"public static readonly TheoryData<{type}> Field = new TheoryData<{type}>() {{ }};";
-		var method = $@"public static TheoryData<{type}> Method(int a, string b) => new TheoryData<{type}>() {{ }};";
-		var property = $@"public static TheoryData<{type}> Property => new TheoryData<{type}>() {{ }};";
+		var c = string.Format(/* lang=c#-test */ "public sealed class Class : TheoryData<{0}> {{ }}", type);
+		var f = string.Format(/* lang=c#-test */ "public static readonly TheoryData<{0}> Field = new TheoryData<{0}>() {{ }};", type);
+		var m = string.Format(/* lang=c#-test */ "public static TheoryData<{0}> Method(int a, string b) => new TheoryData<{0}>() {{ }};", type);
+		var p = string.Format(/* lang=c#-test */ "public static TheoryData<{0}> Property => new TheoryData<{0}>() {{ }};", type);
 
 		return new TheoryData<string, string, string>
 		{
-			{ @class, "ClassData(typeof(Class))", type },
-			{ field, "MemberData(nameof(Field))", type },
-			{ method, @"MemberData(nameof(Method), 1, ""2"")", type },
-			{ property, "MemberData(nameof(Property))", type }
+			{ c, "ClassData(typeof(Class))", type },
+			{ f, "MemberData(nameof(Field))", type },
+			{ m, @"MemberData(nameof(Method), 1, ""2"")", type },
+			{ p, "MemberData(nameof(Property))", type }
 		};
 	}
 
 	public static TheoryData<string, string, string> TheoryDataMembersWithDiscoveryEnumerationDisabled(string type)
 	{
-		var field = $@"public static readonly TheoryData<{type}> Field = new TheoryData<{type}>() {{ }};";
-		var method = $@"public static TheoryData<{type}> Method(int a, string b) => new TheoryData<{type}>() {{ }};";
-		var property = $@"public static TheoryData<{type}> Property => new TheoryData<{type}>() {{ }};";
+		var f = string.Format(/* lang=c#-test */ "public static readonly TheoryData<{0}> Field = new TheoryData<{0}>() {{ }};", type);
+		var m = string.Format(/* lang=c#-test */ "public static TheoryData<{0}> Method(int a, string b) => new TheoryData<{0}>() {{ }};", type);
+		var p = string.Format(/* lang=c#-test */ "public static TheoryData<{0}> Property => new TheoryData<{0}>() {{ }};", type);
 
 		return new TheoryData<string, string, string>
 		{
-			{ field, "MemberData(nameof(Field), DisableDiscoveryEnumeration = true)", type },
-			{ method, @"MemberData(nameof(Method), 1, ""2"", DisableDiscoveryEnumeration = true)", type },
-			{ property, "MemberData(nameof(Property), DisableDiscoveryEnumeration = true)", type }
+			{ f, "MemberData(nameof(Field), DisableDiscoveryEnumeration = true)", type },
+			{ m, @"MemberData(nameof(Method), 1, ""2"", DisableDiscoveryEnumeration = true)", type },
+			{ p, "MemberData(nameof(Property), DisableDiscoveryEnumeration = true)", type }
 		};
 	}
 
 	public sealed class NoDiagnostic : TheoryDataTypeArgumentsShouldBeSerializableTests
 	{
 		[Fact]
-		public async Task GivenMethodWithoutAttributes_FindsNoDiagnostic()
+		public async Task GivenMethodWithoutAttributes_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    public void TestMethod() { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task GivenFact_FindsNoDiagnostic()
+		public async Task GivenFact_DoesNotTrigger()
 		{
-			var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			var source = /* lang=c#-test */ """
+				public class TestClass {
+				    [Xunit.Fact]
+				    public void TestMethod() { }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Fact]
-		public async Task GivenTheory_WithoutTheoryDataAsDataSource_FindsNoDiagnostic()
+		public async Task GivenTheory_WithoutTheoryDataAsDataSource_DoesNotTrigger()
 		{
-			var source = @"
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-    public static IEnumerable<object[]> Property1 => Array.Empty<object[]>();
-    public static DataSource<IDisposable, Action> Property2 => new DataSource<IDisposable, Action>();
-
-    [Theory]
-    [MemberData(nameof(Property1))]
-    [MemberData(nameof(Property2))]
-    public void TestMethod(object a, object b) { }
-}
-
-public class DataSource<T1, T2> : IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() { yield break; }
-    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
-}";
+			var source = /* lang=c#-test */ """
+				using System;
+				using System.Collections;
+				using System.Collections.Generic;
+				using Xunit;
+
+				public class TestClass {
+				    public static IEnumerable<object[]> Property1 => Array.Empty<object[]>();
+				    public static DataSource<IDisposable, Action> Property2 => new DataSource<IDisposable, Action>();
+
+				    [Theory]
+				    [MemberData(nameof(Property1))]
+				    [MemberData(nameof(Property2))]
+				    public void TestMethod(object a, object b) { }
+				}
+
+				public class DataSource<T1, T2> : IEnumerable<object[]> {
+				    public IEnumerator<object[]> GetEnumerator() { yield break; }
+				    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -165,9 +169,7 @@ public class DataSource<T1, T2> : IEnumerable<object[]> {
 		[MemberData(nameof(TheoryDataMembers), "SerializableEnumeration")]
 		[MemberData(nameof(TheoryDataMembers), "SerializableEnumeration?")]
 		[MemberData(nameof(TheoryDataMembers), "Dictionary<string, List<string>>")]
-
 #if NET6_0_OR_GREATER && ROSLYN_4_4_OR_GREATER
-
 		[MemberData(nameof(TheoryDataMembers), "DateOnly")]
 		[MemberData(nameof(TheoryDataMembers), "DateOnly[]")]
 		[MemberData(nameof(TheoryDataMembers), "DateOnly?")]
@@ -176,29 +178,28 @@ public class DataSource<T1, T2> : IEnumerable<object[]> {
 		[MemberData(nameof(TheoryDataMembers), "TimeOnly[]")]
 		[MemberData(nameof(TheoryDataMembers), "TimeOnly?")]
 		[MemberData(nameof(TheoryDataMembers), "TimeOnly?[]")]
-
 #endif
-
-		public async Task GivenTheory_WithSerializableTheoryDataMember_FindsNoDiagnostic(
+		public async Task GivenTheory_WithSerializableTheoryDataMember_DoesNotTrigger(
 			string member,
 			string attribute,
 			string type)
 		{
-			var source = $@"
-using System;
-using System.Collections.Generic;
-using System.Numerics;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Collections.Generic;
+				using System.Numerics;
+				using Xunit;
 
-public class TestClass {{
-    {member}
+				public class TestClass {{
+				    {0}
 
-    [Theory]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+				    [Theory]
+				    [{1}]
+				    public void TestMethod({2} parameter) {{ }}
+				}}
 
-public enum SerializableEnumeration {{ Zero }}";
+				public enum SerializableEnumeration {{ Zero }}
+				""", member, attribute, type);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -214,43 +215,42 @@ public enum SerializableEnumeration {{ Zero }}";
 		[MemberData(nameof(TheoryDataMembers), "SerializableStruct[]")]
 		[MemberData(nameof(TheoryDataMembers), "SerializableStruct?")]
 		[MemberData(nameof(TheoryDataMembers), "SerializableStruct?[]")]
-		public async Task GivenTheory_WithIXunitSerializableTheoryDataMember_FindsNoDiagnostic(
+		public async Task GivenTheory_WithIXunitSerializableTheoryDataMember_DoesNotTrigger(
 			string member,
 			string attribute,
 			string type)
 		{
-			var sourceV2 = GetSource(iXunitSerializableNamespace: "Xunit.Abstractions");
-			var sourceV3 = GetSource(iXunitSerializableNamespace: "Xunit.Sdk");
+			var sourceV2 = GetSource("Xunit.Abstractions");
+			var sourceV3 = GetSource("Xunit.Sdk");
 
 			await Verify.VerifyAnalyzerV2(sourceV2);
 			await Verify.VerifyAnalyzerV3(sourceV3);
 
-			string GetSource(string iXunitSerializableNamespace)
-			{
-				return $@"
-using Xunit;
-using {iXunitSerializableNamespace};
+			string GetSource(string ns) =>
+				string.Format(/* lang=c#-test */ """
+					using Xunit;
+					using {3};
 
-public class TestClass {{
-    {member}
+					public class TestClass {{
+					    {0}
 
-    [Theory]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+					    [Theory]
+					    [{1}]
+					    public void TestMethod({2} parameter) {{ }}
+					}}
 
-public interface ISerializableInterface : IXunitSerializable {{ }}
+					public interface ISerializableInterface : IXunitSerializable {{ }}
 
-public class SerializableClass : ISerializableInterface {{
-    public void Deserialize(IXunitSerializationInfo info) {{ }}
-    public void Serialize(IXunitSerializationInfo info) {{ }}
-}}
+					public class SerializableClass : ISerializableInterface {{
+					    public void Deserialize(IXunitSerializationInfo info) {{ }}
+					    public void Serialize(IXunitSerializationInfo info) {{ }}
+					}}
 
-public struct SerializableStruct : ISerializableInterface {{
-    public void Deserialize(IXunitSerializationInfo info) {{ }}
-    public void Serialize(IXunitSerializationInfo info) {{ }}
-}}";
-			}
+					public struct SerializableStruct : ISerializableInterface {{
+					    public void Deserialize(IXunitSerializationInfo info) {{ }}
+					    public void Serialize(IXunitSerializationInfo info) {{ }}
+					}}
+					""", member, attribute, type, ns);
 		}
 
 		[Theory]
@@ -262,30 +262,31 @@ public void Serialize(IXunitSerializationInfo info) {{ }}
 		[MemberData(nameof(TheoryDataMembers), "object[]")]
 		[MemberData(nameof(TheoryDataMembers), "IPossiblySerializableInterface")]
 		[MemberData(nameof(TheoryDataMembers), "PossiblySerializableUnsealedClass")]
-		public async Task GivenTheory_WithNonSerializableTheoryDataMember_WithDiscoveryEnumerationDisabledForTheory_FindsNoDiagnostic(
+		public async Task GivenTheory_WithNonSerializableTheoryDataMember_WithDiscoveryEnumerationDisabledForTheory_DoesNotTrigger(
 			string member,
 			string attribute,
 			string type)
 		{
-			var source = $@"
-using System;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using Xunit;
 
-public class TestClass {{
-    {member}
+				public class TestClass {{
+				    {0}
 
-    [Theory(DisableDiscoveryEnumeration = true)]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+				    [Theory(DisableDiscoveryEnumeration = true)]
+				    [{1}]
+				    public void TestMethod({2} parameter) {{ }}
+				}}
 
-public sealed class NonSerializableSealedClass {{ }}
+				public sealed class NonSerializableSealedClass {{ }}
 
-public struct NonSerializableStruct {{ }}
+				public struct NonSerializableStruct {{ }}
 
-public interface IPossiblySerializableInterface {{ }}
+				public interface IPossiblySerializableInterface {{ }}
 
-public class PossiblySerializableUnsealedClass {{ }}";
+				public class PossiblySerializableUnsealedClass {{ }}
+				""", member, attribute, type);
 
 			await Verify.VerifyAnalyzerV3(source);
 		}
@@ -299,37 +300,38 @@ public class PossiblySerializableUnsealedClass {{ }}";
 		[MemberData(nameof(TheoryDataMembersWithDiscoveryEnumerationDisabled), "object[]")]
 		[MemberData(nameof(TheoryDataMembersWithDiscoveryEnumerationDisabled), "IPossiblySerializableInterface")]
 		[MemberData(nameof(TheoryDataMembersWithDiscoveryEnumerationDisabled), "PossiblySerializableUnsealedClass")]
-		public async Task GivenTheory_WithNonSerializableTheoryDataMember_WithDiscoveryEnumerationDisabledForMemberData_FindsNoDiagnostic(
+		public async Task GivenTheory_WithNonSerializableTheoryDataMember_WithDiscoveryEnumerationDisabledForMemberData_DoesNotTrigger(
 			string member,
 			string attribute,
 			string type)
 		{
-			var source = $@"
-using System;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using Xunit;
 
-public class TestClass {{
-    {member}
+				public class TestClass {{
+				    {0}
 
-    [Theory]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+				    [Theory]
+				    [{1}]
+				    public void TestMethod({2} parameter) {{ }}
+				}}
 
-public sealed class NonSerializableSealedClass {{ }}
+				public sealed class NonSerializableSealedClass {{ }}
 
-public struct NonSerializableStruct {{ }}
+				public struct NonSerializableStruct {{ }}
 
-public interface IPossiblySerializableInterface {{ }}
+				public interface IPossiblySerializableInterface {{ }}
 
-public class PossiblySerializableUnsealedClass {{ }}";
+				public class PossiblySerializableUnsealedClass {{ }}
+				""", member, attribute, type);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		[Theory]
 		[MemberData(nameof(TheoryDataClass), "int", "double", "string")]
-		public async Task GivenTheory_WithSerializableTheoryDataClass_FindsNoDiagnostic(
+		public async Task GivenTheory_WithSerializableTheoryDataClass_DoesNotTrigger(
 			string source,
 			string _1,
 			string _2,
@@ -341,7 +343,7 @@ public async Task GivenTheory_WithSerializableTheoryDataClass_FindsNoDiagnostic(
 		[Theory]
 		[MemberData(nameof(TheoryDataClass), "Theory(DisableDiscoveryEnumeration = true)", "Action", "TimeZoneInfo", "TimeZoneInfo.TransitionTime")]
 		[MemberData(nameof(TheoryDataClass), "Theory(DisableDiscoveryEnumeration = true)", "object[]", "Array", "IDisposable")]
-		public async Task GivenTheory_WithNonSerializableTheoryDataClass_WithDiscoveryEnumerationDisabled_FindsNoDiagnostic(
+		public async Task GivenTheory_WithNonSerializableTheoryDataClass_WithDiscoveryEnumerationDisabled_DoesNotTrigger(
 			string source,
 			string _1,
 			string _2,
@@ -353,8 +355,6 @@ public async Task GivenTheory_WithNonSerializableTheoryDataClass_WithDiscoveryEn
 
 	public sealed class X1044_AvoidUsingTheoryDataTypeArgumentsThatAreNotSerializable : TheoryDataTypeArgumentsShouldBeSerializableTests
 	{
-		const string Id = "xUnit1044";
-
 		[Theory]
 		[MemberData(nameof(TheoryDataMembers), "Delegate")]
 		[MemberData(nameof(TheoryDataMembers), "Delegate[]")]
@@ -366,76 +366,53 @@ public sealed class X1044_AvoidUsingTheoryDataTypeArgumentsThatAreNotSerializabl
 		[MemberData(nameof(TheoryDataMembers), "NonSerializableStruct[]")]
 		[MemberData(nameof(TheoryDataMembers), "NonSerializableStruct?")]
 		[MemberData(nameof(TheoryDataMembers), "NonSerializableStruct?[]")]
-		public async Task GivenTheory_WithNonSerializableTheoryDataMember_FindsDiagnostic(
+		public async Task GivenTheory_WithNonSerializableTheoryDataMember_Triggers(
 			string member,
 			string attribute,
 			string type)
 		{
-			var source = $@"
-using System;
-using System.Text;
-using Xunit;
-
-public class TestClass {{
-    {member}
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Text;
+				using Xunit;
 
-    [Theory]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+				public class TestClass {{
+				    {0}
 
-public sealed class NonSerializableSealedClass {{ }}
+				    [Theory]
+				    [{{|#0:{1}|}}]
+				    public void TestMethod({2} parameter) {{ }}
+				}}
 
-public struct NonSerializableStruct {{ }}";
+				public sealed class NonSerializableSealedClass {{ }}
 
-			var expected =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(10, 6, 10, 6 + attribute.Length)
-					.WithArguments(type);
+				public struct NonSerializableStruct {{ }}
+				""", member, attribute, type);
+			var expected = Verify.Diagnostic("xUnit1044").WithLocation(0).WithArguments(type);
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(TheoryDataClass), "Action", "TimeZoneInfo", "TimeZoneInfo.TransitionTime")]
-		public async Task GivenTheory_WithNonSerializableTheoryDataClass_FindsDiagnostic(
+		public async Task GivenTheory_WithNonSerializableTheoryDataClass_Triggers(
 			string source,
 			string type1,
 			string type2,
 			string type3)
 		{
-			var expectedForType1 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type1);
-
-			var expectedForType2 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type2);
-
-			var expectedForType3 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type3);
-
-			await Verify.VerifyAnalyzer(
-				source,
-				expectedForType1,
-				expectedForType2,
-				expectedForType3
-			);
+			var expected = new[] {
+				Verify.Diagnostic("xUnit1044").WithSpan(6, 6, 6, 37).WithArguments(type1),
+				Verify.Diagnostic("xUnit1044").WithSpan(6, 6, 6, 37).WithArguments(type2),
+				Verify.Diagnostic("xUnit1044").WithSpan(6, 6, 6, 37).WithArguments(type3),
+			};
+
+			await Verify.VerifyAnalyzer(source, expected);
 		}
 	}
 
 	public sealed class X1045_AvoidUsingTheoryDataTypeArgumentsThatMightNotBeSerializable : TheoryDataTypeArgumentsShouldBeSerializableTests
 	{
-		const string Id = "xUnit1045";
-
 		[Theory]
 		[MemberData(nameof(TheoryDataMembers), "object")]
 		[MemberData(nameof(TheoryDataMembers), "object[]")]
@@ -453,70 +430,49 @@ public sealed class X1045_AvoidUsingTheoryDataTypeArgumentsThatMightNotBeSeriali
 		[MemberData(nameof(TheoryDataMembers), "IPossiblySerializableInterface[]")]
 		[MemberData(nameof(TheoryDataMembers), "PossiblySerializableUnsealedClass")]
 		[MemberData(nameof(TheoryDataMembers), "PossiblySerializableUnsealedClass[]")]
-		public async Task GivenTheory_WithPossiblySerializableTheoryDataMember_FindsDiagnostic(
+		public async Task GivenTheory_WithPossiblySerializableTheoryDataMember_Triggers(
 			string member,
 			string attribute,
 			string type)
 		{
-			var source = $@"
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using System;
+				using System.Collections;
+				using System.Collections.Generic;
+				using Xunit;
 
-public class TestClass {{
-    {member}
+				public class TestClass {{
+				    {0}
 
-    [Theory]
-    [{attribute}]
-    public void TestMethod({type} parameter) {{ }}
-}}
+				    [Theory]
+				    [{{|#0:{1}|}}]
+				    public void TestMethod({2} parameter) {{ }}
+				}}
 
-public interface IPossiblySerializableInterface {{ }}
+				public interface IPossiblySerializableInterface {{ }}
 
-public class PossiblySerializableUnsealedClass {{ }}";
-
-			var expected =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(11, 6, 11, 6 + attribute.Length)
-					.WithArguments(type);
+				public class PossiblySerializableUnsealedClass {{ }}
+				""", member, attribute, type);
+			var expected = Verify.Diagnostic("xUnit1045").WithLocation(0).WithArguments(type);
 
 			await Verify.VerifyAnalyzer(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(TheoryDataClass), "object[]", "Array", "IDisposable")]
-		public async Task GivenTheory_WithPossiblySerializableTheoryDataClass_FindsDiagnostic(
+		public async Task GivenTheory_WithPossiblySerializableTheoryDataClass_Triggers(
 			string source,
 			string type1,
 			string type2,
 			string type3)
 		{
-			var expectedForType1 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type1);
-
-			var expectedForType2 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type2);
-
-			var expectedForType3 =
-				Verify
-					.Diagnostic(Id)
-					.WithSpan(7, 6, 7, 37)
-					.WithArguments(type3);
-
-			await Verify.VerifyAnalyzer(
-				source,
-				expectedForType1,
-				expectedForType2,
-				expectedForType3
-			);
+			var expected = new[] {
+				Verify.Diagnostic("xUnit1045").WithSpan(6, 6, 6, 37).WithArguments(type1),
+				Verify.Diagnostic("xUnit1045").WithSpan(6, 6, 6, 37).WithArguments(type2),
+				Verify.Diagnostic("xUnit1045").WithSpan(6, 6, 6, 37).WithArguments(type3),
+			};
+
+			await Verify.VerifyAnalyzer(source, expected);
 		}
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveDefaultParameterTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveDefaultParameterTests.cs
index 428d9d08..4302ba4e 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveDefaultParameterTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveDefaultParameterTests.cs
@@ -9,31 +9,28 @@
 public class TheoryMethodCannotHaveDefaultParameterTests
 {
 	[Fact]
-	public async Task FindsErrorForTheoryWithDefaultParameter_WhenDefaultValueNotSupported()
+	public async Task TheoryWithDefaultParameter_WhenDefaultValueNotSupported_Triggers()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, string c = """") { }
-}";
-		var expected =
-			Verify_v2_Pre220
-				.Diagnostic()
-				.WithSpan(4, 54, 4, 58)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "c");
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, string c {|#0:= ""|}) { }
+			}
+			""";
+		var expected = Verify_v2_Pre220.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "c");
 
 		await Verify_v2_Pre220.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryWithDefaultParameter_WhenDefaultValueSupported()
+	public async Task TheoryWithDefaultParameter_WhenDefaultValueSupported_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, string c = """") { }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, string c = "") { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveParamsArrayTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveParamsArrayTests.cs
index ac6ce7db..f810a328 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveParamsArrayTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodCannotHaveParamsArrayTests.cs
@@ -9,55 +9,54 @@
 public class TheoryMethodCannotHaveParamsArrayTests
 {
 	[Fact]
-	public async Task FindsErrorForTheoryWithParamsArrayAsync_WhenParamsArrayNotSupported()
+	public async Task TheoryWithParamsArrayAsync_WhenParamsArrayNotSupported_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, params string[] c) { }
-}";
-		var expected =
-			Verify_v2_Pre220
-				.Diagnostic()
-				.WithSpan(4, 45, 4, 62)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("TestMethod", "TestClass", "c");
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, {|#0:params string[] c|}) { }
+			}
+			""";
+		var expected = Verify_v2_Pre220.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "c");
 
 		await Verify_v2_Pre220.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryWithParamsArrayAsync_WhenParamsArraySupported()
+	public async Task TheoryWithParamsArrayAsync_WhenParamsArraySupported_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, params string[] c) { }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, params string[] c) { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryWithNonParamsArrayAsync_WhenParamsArrayNotSupported()
+	public async Task TheoryWithNonParamsArrayAsync_WhenParamsArrayNotSupported_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, string[] c) { }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, string[] c) { }
+			}
+			""";
 
 		await Verify_v2_Pre220.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryWithNonParamsArrayAsync_WhenParamsArraySupported()
+	public async Task TheoryWithNonParamsArrayAsync_WhenParamsArraySupported_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(int a, string b, string[] c) { }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(int a, string b, string[] c) { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodMustHaveTestDataTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodMustHaveTestDataTests.cs
index 5a09b952..3e895a48 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodMustHaveTestDataTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodMustHaveTestDataTests.cs
@@ -5,13 +5,14 @@
 public class TheoryMethodMustHaveTestDataTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForFactMethod()
+	public async Task FactMethod_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -20,31 +21,29 @@ public void TestMethod() { }
 	[InlineData("InlineData")]
 	[InlineData("MemberData(\"\")")]
 	[InlineData("ClassData(typeof(string))")]
-	public async Task DoesNotFindErrorForTheoryMethodWithDataAttributes(string dataAttribute)
+	public async Task TheoryMethodWithDataAttributes_DoesNotTrigger(string dataAttribute)
 	{
-		var source = $@"
-public class TestClass {{
-    [Xunit.Theory]
-    [Xunit.{dataAttribute}]
-    public void TestMethod() {{ }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    [Xunit.Theory]
+			    [Xunit.{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", dataAttribute);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsErrorForTheoryMethodMissingData()
+	public async Task TheoryMethodMissingData_Triggers()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void [|TestMethod|]() { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldHaveParametersTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldHaveParametersTests.cs
index 3c0a246a..4e3777a2 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldHaveParametersTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldHaveParametersTests.cs
@@ -5,42 +5,41 @@
 public class TheoryMethodShouldHaveParametersTests
 {
 	[Fact]
-	public async Task DoesNotFindErrorForFactMethod()
+	public async Task FactMethod_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindErrorForTheoryMethodWithParameters()
+	public async Task TheoryMethodWithParameters_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Theory]
-    public void TestMethod(string s) { }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Theory]
+			    public void TestMethod(string s) { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsErrorForTheoryMethodWithoutParameters()
+	public async Task TheoryMethodWithoutParameters_Triggers()
 	{
-		var source = @"
-class TestClass {
-    [Xunit.Theory]
-    public void TestMethod() { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 17, 4, 27);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    [Xunit.Theory]
+			    public void [|TestMethod|]() { }
+			}
+			""";
 
-		await Verify.VerifyAnalyzer(source, expected);
+		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldUseAllParametersTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldUseAllParametersTests.cs
index 9b5df85e..8b6fbaa3 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldUseAllParametersTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/TheoryMethodShouldUseAllParametersTests.cs
@@ -1,210 +1,177 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.TheoryMethodShouldUseAllParameters>;
 
 public class TheoryMethodShouldUseAllParametersTests
 {
 	[Fact]
-	public async Task FindsWarning_ParameterNotReferenced()
+	public async Task ParameterNotReferenced_Triggers()
 	{
-		var source = @"
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using Xunit;
 
-class TestClass {
-    [Theory]
-    void TestMethod(int unused) { }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 25, 6, 31)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "unused");
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int {|#0:unused|}) { }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "unused");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ParameterUnread()
+	public async Task ParameterUnread_Triggers()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(int unused) {
-        unused = 3;
-        int.TryParse(""123"", out unused);
-    }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 25, 7, 31)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "unused");
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int {|#0:unused|}) {
+			        unused = 3;
+			        int.TryParse("123", out unused);
+			    }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "unused");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_MultipleUnreadParameters()
+	public async Task MultipleUnreadParameters_Triggers()
 	{
-		var source = @"
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(int foo, int bar, int baz) { }
-}";
+		var source = /* lang=c#-test */ """
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int {|#0:foo|}, int {|#1:bar|}, int {|#2:baz|}) { }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 25, 6, 28)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "foo"),
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 34, 6, 37)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "bar"),
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 43, 6, 46)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "baz"),
+			Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "foo"),
+			Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass", "bar"),
+			Verify.Diagnostic().WithLocation(2).WithArguments("TestMethod", "TestClass", "baz"),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_SomeUnreadParameters()
+	public async Task SomeUnreadParameters_Triggers()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(int foo, int bar, int baz) {
-        Console.WriteLine(bar);
-        baz = 3;
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int {|#0:foo|}, int bar, int {|#1:baz|}) {
+			        Console.WriteLine(bar);
+			        baz = 3;
+			    }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 25, 7, 28)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "foo"),
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 43, 7, 46)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "baz"),
+			Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "foo"),
+			Verify.Diagnostic().WithLocation(1).WithArguments("TestMethod", "TestClass", "baz"),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ExpressionBodiedMethod()
+	public async Task ExpressionBodiedMethod_Triggers()
 	{
-		var source = @"
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using Xunit;
 
-class TestClass {
-    [Theory]
-    void TestMethod(int unused) => Assert.Equal(5, 2 + 2);
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 25, 6, 31)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "unused");
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int {|#0:unused|}) => Assert.Equal(5, 2 + 2);
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "unused");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ParameterRead()
+	public async Task ParameterRead_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(int used) {
-        Console.WriteLine(used);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int used) {
+			        Console.WriteLine(used);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ParameterCapturedAsOutParameterInMockSetup()
+	public async Task ParameterCapturedAsOutParameterInMockSetup_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(string used, int usedOut) {
-        // mimicking mock setup use case
-        // var mock = new Mock<IHaveOutParameter>();
-        // mock.Setup(m => m.SomeMethod(out used));
-        Action setup = () => int.TryParse(used, out usedOut);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(string used, int usedOut) {
+			        // mimicking mock setup use case
+			        // var mock = new Mock<IHaveOutParameter>();
+			        // mock.Setup(m => m.SomeMethod(out used));
+			        Action setup = () => int.TryParse(used, out usedOut);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ExpressionBodiedMethod()
+	public async Task ExpressionBodiedMethod_DoesNotTrigger()
 	{
-		var source = @"
-using Xunit;
+		var source = /* lang=c#-test */ """
+			using Xunit;
 
-class TestClass {
-    [Theory]
-    void TestMethod(int used) => Assert.Equal(used, 2 + 2);
-}";
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int used) => Assert.Equal(used, 2 + 2);
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_WhenParameterIsDiscardNamed()
+	public async Task WhenParameterIsDiscardNamed_DoesNotTrigger()
 	{
-		var source = @"
-using System;
-using Xunit;
-
-class TestClass {
-    [Theory]
-    void TestMethod(int used, string _, object _1, DateTime _42, double _a)
-    {
-        Assert.Equal(42, used);
-    }
-}";
-
+		var source = /* lang=c#-test */ """
+			using System;
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    void TestMethod(int used, string _, object _1, DateTime _42, double {|#0:_a|})
+			    {
+			        Assert.Equal(42, used);
+			    }
+			}
+			""";
 		// Only a single warning, for _a; everything else is either used or matches the discard pattern
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 73, 7, 75)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("TestMethod", "TestClass", "_a");
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("TestMethod", "TestClass", "_a");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -212,13 +179,14 @@ void TestMethod(int used, string _, object _1, DateTime _42, double _a)
 	[Fact]
 	public async Task DoesNotCrash_MethodWithoutBody()
 	{
-		var source = @"
-using Xunit;
-
-class TestClass {
-    [Theory]
-    extern void TestMethod(int foo);
-}";
+		var source = /* lang=c#-test */ """
+			using Xunit;
+
+			class TestClass {
+			    [Theory]
+			    extern void TestMethod(int foo);
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/UseCancellationTokenTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/UseCancellationTokenTests.cs
index 7ee3f6a5..160e3cce 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/UseCancellationTokenTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/UseCancellationTokenTests.cs
@@ -8,16 +8,17 @@ public class UseCancellationTokenTests
 	[Fact]
 	public async Task NoCancellationToken_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading;
-using Xunit;
-
-class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Thread.Sleep(1);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading;
+			using Xunit;
+
+			class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        Thread.Sleep(1);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV3(source);
 	}
@@ -27,17 +28,18 @@ public void TestMethod() {
 	[InlineData("new CancellationTokenSource().Token")]
 	public async Task WithAnyCancellationToken_DoesNotTrigger(string token)
 	{
-		var source = @$"
-using System.Threading;
-using System.Threading.Tasks;
-using Xunit;
-
-class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        await Task.Delay(1, {token});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Threading;
+			using System.Threading.Tasks;
+			using Xunit;
+
+			class TestClass {{
+			    [Fact]
+			    public async Task TestMethod() {{
+			        await Task.Delay(1, {0});
+			    }}
+			}}
+			""", token);
 
 		await Verify.VerifyAnalyzerV3(source);
 	}
@@ -45,17 +47,18 @@ public async Task TestMethod() {{
 	[Fact]
 	public async Task WithoutCancellationToken_V2_DoesNotTrigger()
 	{
-		var source = @$"
-using System.Threading;
-using System.Threading.Tasks;
-using Xunit;
-
-class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        await Task.Delay(1);
-    }}
-}}";
+		var source = /* lang=c#-test */ """
+			using System.Threading;
+			using System.Threading.Tasks;
+			using Xunit;
+
+			class TestClass {
+			    [Fact]
+			    public async Task TestMethod() {
+			        await Task.Delay(1);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV2(source);
 	}
@@ -63,20 +66,21 @@ public async Task TestMethod() {{
 	[Fact]
 	public async Task WithoutCancellationToken_WithoutDirectUpgrade_DoesNotTrigger()
 	{
-		var source = @"
-using System.Threading;
-using System.Threading.Tasks;
-using Xunit;
-
-class TestClass {
-    [Fact]
-    public void TestMethod() {
-        FunctionWithOverload(42);
-    }
-
-    void FunctionWithOverload(int _) { }
-    void FunctionWithOverload(CancellationToken _) { }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Threading;
+			using System.Threading.Tasks;
+			using Xunit;
+
+			class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        FunctionWithOverload(42);
+			    }
+
+			    void FunctionWithOverload(int _) { }
+			    void FunctionWithOverload(CancellationToken _) { }
+			}
+			""";
 
 		await Verify.VerifyAnalyzerV3(source);
 	}
@@ -93,27 +97,24 @@ void FunctionWithOverload(CancellationToken _) { }
 	[InlineData("FunctionWithOverload(42, default(CancellationToken))")]
 	public async Task WithoutCancellationToken_V3_Triggers(string invocation)
 	{
-		var source = @$"
-using System.Threading;
-using System.Threading.Tasks;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Threading;
+			using System.Threading.Tasks;
+			using Xunit;
 
-class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        {invocation};
-    }}
+			class TestClass {{
+			    [Fact]
+			    public void TestMethod() {{
+			        [|{0}|];
+			    }}
 
-    void FunctionWithDefaults(int _1 = 2112, CancellationToken cancellationToken = default) {{ }}
+			    void FunctionWithDefaults(int _1 = 2112, CancellationToken cancellationToken = default) {{ }}
 
-    void FunctionWithOverload(int _) {{ }}
-    void FunctionWithOverload(int _1, CancellationToken _2) {{ }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(9, 9, 9, 9 + invocation.Length);
+			    void FunctionWithOverload(int _) {{ }}
+			    void FunctionWithOverload(int _1, CancellationToken _2) {{ }}
+			}}
+			""", invocation);
 
-		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp7_1, source, expected);
+		await Verify.VerifyAnalyzerV3(LanguageVersion.CSharp7_1, source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertCollectionContainsShouldNotUseBoolCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertCollectionContainsShouldNotUseBoolCheckTests.cs
index 1b8900e2..b450dff6 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertCollectionContainsShouldNotUseBoolCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertCollectionContainsShouldNotUseBoolCheckTests.cs
@@ -5,228 +5,216 @@
 
 public class AssertCollectionContainsShouldNotUseBoolCheckTests
 {
-	public static TheoryData<string> Collections = new()
-	{
+	public static TheoryData<string> Collections =
+	[
 		"new System.Collections.Generic.List<int>()",
 		"new System.Collections.Generic.HashSet<int>()",
 		"new System.Collections.ObjectModel.Collection<int>()",
-	};
-	public static TheoryData<string> Enumerables = new()
-	{
+	];
+	public static TheoryData<string> Enumerables =
+	[
 		"new int[0]",
 		"System.Linq.Enumerable.Empty<int>()",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task FindsWarningForTrueCollectionContainsCheck(string collection)
+	public async Task TrueCollectionContainsCheck_Triggers(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True({collection}.Contains(1));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 40 + collection.Length)
-				.WithArguments("Assert.True()", Constants.Asserts.Contains);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.True({0}.Contains(1))|}};
+			    }}
+			}}
+			""", collection);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.Contains);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task FindsWarningForFalseCollectionContainsCheck(string collection)
+	public async Task FalseCollectionContainsCheck_Triggers(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False({collection}.Contains(1));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 41 + collection.Length)
-				.WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.False({0}.Contains(1))|}};
+			    }}
+			}}
+			""", collection);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task FindsWarningForTrueLinqContainsCheck(string enumerable)
+	public async Task TrueLinqContainsCheck_Triggers(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True({enumerable}.Contains(1));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 9, 6, 40 + enumerable.Length)
-				.WithArguments("Assert.True()", Constants.Asserts.Contains);
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.True({0}.Contains(1))|}};
+			    }}
+			}}
+			""", enumerable);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.Contains);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task FindsWarningForTrueLinqContainsCheckWithEqualityComparer(string enumerable)
+	public async Task TrueLinqContainsCheckWithEqualityComparer_Triggers(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True({enumerable}.Contains(1, System.Collections.Generic.EqualityComparer<int>.Default));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 9, 6, 98 + enumerable.Length)
-				.WithArguments("Assert.True()", Constants.Asserts.Contains);
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.True({0}.Contains(1, System.Collections.Generic.EqualityComparer<int>.Default))|}};
+			    }}
+			}}
+			""", enumerable);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.Contains);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task FindsWarningForFalseLinqContainsCheck(string enumerable)
+	public async Task FalseLinqContainsCheck_Triggers(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False({enumerable}.Contains(1));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 9, 6, 41 + enumerable.Length)
-				.WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.False({0}.Contains(1))|}};
+			    }}
+			}}
+			""", enumerable);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task FindsWarningForFalseLinqContainsCheckWithEqualityComparer(string enumerable)
+	public async Task FalseLinqContainsCheckWithEqualityComparer_Triggers(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False({enumerable}.Contains(1, System.Collections.Generic.EqualityComparer<int>.Default));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 9, 6, 99 + enumerable.Length)
-				.WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.False({0}.Contains(1, System.Collections.Generic.EqualityComparer<int>.Default))|}};
+			    }}
+			}}
+			""", enumerable);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.False()", Constants.Asserts.DoesNotContain);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task DoesNotFindWarningForTrueCollectionContainsCheckWithAssertionMessage(string collection)
+	public async Task TrueCollectionContainsCheckWithAssertionMessage_DoesNotTrigger(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True({collection}.Contains(1), ""Custom message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.True({0}.Contains(1), "Custom message");
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task DoesNotFindWarningForFalseCollectionContainsCheckWithAssertionMessage(string collection)
+	public async Task FalseCollectionContainsCheckWithAssertionMessage_DoesNotTrigger(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False({collection}.Contains(1), ""Custom message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.False({0}.Contains(1), "Custom message");
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task DoesNotFindWarningForTrueLinqContainsCheckWithAssertionMessage(string enumerable)
+	public async Task TrueLinqContainsCheckWithAssertionMessage_DoesNotTrigger(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
 
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True({enumerable}.Contains(1), ""Custom message"");
-    }}
-}}";
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.True({0}.Contains(1), "Custom message");
+			    }}
+			}}
+			""", enumerable);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Enumerables))]
-	public async Task DoesNotFindWarningForFalseLinqContainsCheckWithAssertionMessage(string enumerable)
+	public async Task FalseLinqContainsCheckWithAssertionMessage_DoesNotTrigger(string enumerable)
 	{
-		var source = $@"
-using System.Linq;
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
 
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False({enumerable}.Contains(1), ""Custom message"");
-    }}
-}}";
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.False({0}.Contains(1), "Custom message");
+			    }}
+			}}
+			""", enumerable);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotCrashForCollectionWithDifferentTypeParametersThanICollectionImplementation_ZeroParameters()
+	public async Task CollectionWithDifferentTypeParametersThanICollectionImplementation_ZeroParameters_Triggers()
 	{
-		var source = @"
-using System.Collections.Generic;
+		var source = /* lang=c#-test */ """
+			using System.Collections.Generic;
 
-class IntList : List<int> { }
+			class IntList : List<int> { }
 
-class TestClass {
-    void TestMethod() {
-        [|Xunit.Assert.False(new IntList().Contains(1))|];
-    }
-}";
+			class TestClass {
+			    void TestMethod() {
+			        [|Xunit.Assert.False(new IntList().Contains(1))|];
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotCrashForCollectionWithDifferentTypeParametersThanICollectionImplementation_TwoParameters()
+	public async Task CollectionWithDifferentTypeParametersThanICollectionImplementation_TwoParameters_DoesNotTrigger()
 	{
-		var source = @"
-using System.Collections.Generic;
-
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.False(new Dictionary<int, int>().ContainsKey(1));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Collections.Generic;
+
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.False(new Dictionary<int, int>().ContainsKey(1));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyCollectionCheckShouldNotBeUsedTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyCollectionCheckShouldNotBeUsedTests.cs
index b53014b4..7e45adec 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyCollectionCheckShouldNotBeUsedTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyCollectionCheckShouldNotBeUsedTests.cs
@@ -4,8 +4,8 @@
 
 public class AssertEmptyCollectionCheckShouldNotBeUsedTests
 {
-	public static TheoryData<string> Collections = new()
-	{
+	public static TheoryData<string> Collections =
+	[
 		"new int[0]",
 		"new System.Collections.Generic.List<int>()",
 		"new System.Collections.Generic.HashSet<int>()",
@@ -14,34 +14,36 @@ public class AssertEmptyCollectionCheckShouldNotBeUsedTests
 #if NETCOREAPP3_0_OR_GREATER
 		"default(System.Collections.Generic.IAsyncEnumerable<int>)",
 #endif
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task FindsWarningForCollectionCheckWithoutAction(string collection)
+	public async Task CollectionCheckWithoutAction_Triggers(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        [|Xunit.Assert.Collection({collection})|];
-        [|Xunit.Assert.CollectionAsync({collection})|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.Collection({0})|];
+			        [|Xunit.Assert.CollectionAsync({0})|];
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Collections))]
-	public async Task DoesNotFindWarningForCollectionCheckWithAction(string collection)
+	public async Task CollectionCheckWithAction_DoesNotTrigger(string collection)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.Collection({collection}, i => Xunit.Assert.True(true));
-        Xunit.Assert.CollectionAsync({collection}, async i => {{ await System.Threading.Tasks.Task.Yield(); Xunit.Assert.True(true); }});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Collection({0}, i => Xunit.Assert.True(true));
+			        Xunit.Assert.CollectionAsync({0}, async i => {{ await System.Threading.Tasks.Task.Yield(); Xunit.Assert.True(true); }});
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckTests.cs
index d806fc0f..b1375e1e 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckTests.cs
@@ -23,14 +23,14 @@ public async Task Containers_WithoutWhereClause_DoesNotTrigger(
 		string collection,
 		string _)
 	{
-		var source = $@"
-class TestClass
-{{
-    void TestMethod()
-    {{
-        Xunit.Assert.Empty({collection});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Empty({0});
+			    }}
+			}}
+			""", collection);
+
 		await Verify.VerifyAnalyzer(source);
 	}
 
@@ -41,15 +41,15 @@ public async Task Containers_WithWhereClause_Triggers(
 		string collection,
 		string comparison)
 	{
-		var source = $@"
-using System.Linq;
-class TestClass
-{{
-    void TestMethod()
-    {{
-        [|Xunit.Assert.Empty({collection}.Where(f => {comparison}))|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.Empty({0}.Where(f => {1}))|];
+			    }}
+			}}
+			""", collection, comparison);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -61,15 +61,16 @@ public async Task Containers_WithWhereClauseWithIndex_DoesNotTrigger(
 		string collection,
 		string comparison)
 	{
-		var source = $@"
-using System.Linq;
-class TestClass
-{{
-    void TestMethod()
-    {{
-        Xunit.Assert.Empty({collection}.Where((f, i) => {comparison} && i > 0));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Empty({0}.Where((f, i) => {1} && i > 0));
+			    }}
+			}}
+			""", collection, comparison);
+
 		await Verify.VerifyAnalyzer(source);
 	}
 
@@ -80,34 +81,34 @@ public async Task DoesNotFindWarningForEnumurableEmptyCheckWithChainedLinq(
 		string collection,
 		string comparison)
 	{
-		var source = $@"
-using System.Linq;
-class TestClass
-{{
-    void TestMethod()
-    {{
-        Xunit.Assert.Empty({collection}.Where(f => {comparison}).Select(f => f));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Empty({0}.Where(f => {1}).Select(f => f));
+			    }}
+			}}
+			""", collection, comparison);
 		await Verify.VerifyAnalyzer(source);
 	}
 
-	public static TheoryData<string> GetSampleStrings() =>
-		new(string.Empty, "123", @"abc\n\t\\\""");
-
 	[Theory]
-	[MemberData(nameof(GetSampleStrings))]
+	[InlineData("")]
+	[InlineData("123")]
+	[InlineData(@"abc\n\t\\\""")]
 	public async Task Strings_WithWhereClause_DoesNotTrigger(string sampleString)
 	{
-		var source = $@"
-using System.Linq;
-class TestClass
-{{
-    void TestMethod()
-    {{
-        [|Xunit.Assert.Empty(""{sampleString}"".Where(f => f > 0))|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.Empty("{0}".Where(f => f > 0))|];
+			    }}
+			}}
+			""", sampleString);
+
 		await Verify.VerifyAnalyzer(source);
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckTests.cs
index 7e01323b..c500071c 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckTests.cs
@@ -5,24 +5,25 @@
 
 public class AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		Constants.Asserts.True,
 		Constants.Asserts.False,
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsWarning_ForLinqAnyCheck(string method)
+	public async Task ForLinqAnyCheck_Triggers(string method)
 	{
-		var source = $@"
-using System.Linq;
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
 
-class TestClass {{
-    void TestMethod() {{
-        [|Xunit.Assert.{method}(new [] {{ 1 }}.Any(i => true))|];
-    }}
-}}";
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.{0}(new [] {{ 1 }}.Any(i => true))|];
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualGenericShouldNotBeUsedForStringValueTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualGenericShouldNotBeUsedForStringValueTests.cs
index c0274113..86ea238b 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualGenericShouldNotBeUsedForStringValueTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualGenericShouldNotBeUsedForStringValueTests.cs
@@ -17,64 +17,68 @@ public class AssertEqualGenericShouldNotBeUsedForStringValueTests
 
 	[Theory]
 	[MemberData(nameof(Data))]
-	public async Task DoesNotFindWarningForStringEqualityCheckWithoutGenericType(
+	public async Task StringEqualityCheckWithoutGenericType_DoesNotTrigger(
 		string expected,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.Equal({expected}, {value});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Equal({0}, {1});
+			    }}
+			}}
+			""", expected, value);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Data))]
-	public async Task FindsWarningForStringEqualityCheckWithGenericType(
+	public async Task StringEqualityCheckWithGenericType_Triggers(
 		string expected,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        [|Xunit.Assert.Equal<string>({expected}, {value})|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.Equal<string>({0}, {1})|];
+			    }}
+			}}
+			""", expected, value);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Data))]
-	public async Task FindsWarningForStrictStringEqualityCheck(
+	public async Task StrictStringEqualityCheck_Triggers(
 		string expected,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        [|Xunit.Assert.StrictEqual({expected}, {value})|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.StrictEqual({0}, {1})|];
+			    }}
+			}}
+			""", expected, value);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Data))]
-	public async Task FindsWarningForStrictStringEqualityCheckWithGenericType(
+	public async Task StrictStringEqualityCheckWithGenericType_Triggers(
 		string expected,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        [|Xunit.Assert.StrictEqual<string>({expected}, {value})|];
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        [|Xunit.Assert.StrictEqual<string>({0}, {1})|];
+			    }}
+			}}
+			""", expected, value);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualLiteralValueShouldBeFirstTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualLiteralValueShouldBeFirstTests.cs
index 273101a3..af01461a 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualLiteralValueShouldBeFirstTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualLiteralValueShouldBeFirstTests.cs
@@ -5,14 +5,15 @@
 public class AssertEqualLiteralValueShouldBeFirstTests
 {
 	[Fact]
-	public async Task DoesNotFindWarningWhenConstantOrLiteralUsedForBothArguments()
+	public async Task WhenConstantOrLiteralUsedForBothArguments_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.Equal(""TestMethod"", nameof(TestMethod));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.Equal("TestMethod", nameof(TestMethod));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -32,52 +33,51 @@ void TestMethod() {
 
 	[Theory]
 	[MemberData(nameof(TypesAndValues))]
-	public async Task DoesNotFindWarningForExpectedConstantOrLiteralValueAsFirstArgument(
+	public async Task ExpectedConstantOrLiteralValueAsFirstArgument_DoesNotTrigger(
 		string type,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var v = default({type});
-        Xunit.Assert.Equal({value}, v);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var v = default({0});
+			        Xunit.Assert.Equal({1}, v);
+			    }}
+			}}
+			""", type, value);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarningForConstantsUsedInStringConstructorAsFirstArgument()
+	public async Task ConstantsUsedInStringConstructorAsFirstArgument_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.Equal(new string(' ', 4), ""    "");
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.Equal(new string(' ', 4), "    ");
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(TypesAndValues))]
-	public async Task FindsWarningForExpectedConstantOrLiteralValueAsSecondArgument(
+	public async Task ExpectedConstantOrLiteralValueAsSecondArgument_Triggers(
 		string type,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var v = default({type});
-        Xunit.Assert.Equal(v, {value});
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(5, 9)
-				.WithArguments(value, "Assert.Equal(expected, actual)", "TestMethod", "TestClass");
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var v = default({0});
+			        {{|#0:Xunit.Assert.Equal(v, {1})|}};
+			    }}
+			}}
+			""", type, value);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(value, "Assert.Equal(expected, actual)", "TestMethod", "TestClass");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -85,38 +85,35 @@ void TestMethod() {{
 	[Theory]
 	[InlineData(true)]
 	[InlineData(false)]
-	public async Task DoesNotFindWarningForExpectedConstantOrLiteralValueAsNamedExpectedArgument(bool useAlternateForm)
+	public async Task ExpectedConstantOrLiteralValueAsNamedExpectedArgument_DoesNotTrigger(bool useAlternateForm)
 	{
-		var prefix = useAlternateForm ? "@" : "";
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var v = default(int);
-        Xunit.Assert.Equal({prefix}actual: v, {prefix}expected: 0);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var v = default(int);
+			        Xunit.Assert.Equal({0}actual: v, {0}expected: 0);
+			    }}
+			}}
+			""", useAlternateForm ? "@" : "");
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(TypesAndValues))]
-	public async Task FindsWarningForExpectedConstantOrLiteralValueAsNamedExpectedArgument(
+	public async Task ExpectedConstantOrLiteralValueAsNamedExpectedArgument_Triggers(
 		string type,
 		string value)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var v = default({type});
-        Xunit.Assert.Equal(actual: {value}, expected: v);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(5, 9)
-				.WithArguments(value, "Assert.Equal(expected, actual)", "TestMethod", "TestClass");
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var v = default({0});
+			        {{|#0:Xunit.Assert.Equal(actual: {1}, expected: v)|}};
+			    }}
+			}}
+			""", type, value);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(value, "Assert.Equal(expected, actual)", "TestMethod", "TestClass");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -131,13 +128,14 @@ public async Task DoesNotFindWarningWhenArgumentsAreNotNamedCorrectly(
 		string firstArgumentName,
 		string secondArgumentName)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var v = default(int);
-        Xunit.Assert.{methodName}({firstArgumentName}: 1, {secondArgumentName}: v);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var v = default(int);
+			        Xunit.Assert.{0}({1}: 1, {2}: v);
+			    }}
+			}}
+			""", methodName, firstArgumentName, secondArgumentName);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualPrecisionShouldBeInRangeTest.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualPrecisionShouldBeInRangeTest.cs
index 254c9d9d..4dee1b9e 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualPrecisionShouldBeInRangeTest.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualPrecisionShouldBeInRangeTest.cs
@@ -1,16 +1,16 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertEqualPrecisionShouldBeInRange>;
 
 public class AssertEqualPrecisionShouldBeInRangeTest
 {
-	static readonly string Template = @"
-class TestClass {{
-    void TestMethod() {{
-        {0}
-    }}
-}}";
+	static readonly string Template = /* lang=c#-test */ """
+		class TestClass {{
+		    void TestMethod() {{
+		        {0}
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData(0)]
@@ -39,14 +39,9 @@ public async Task FindsError_ForDoubleArgumentWithPrecisionProvidedOutOfRange(in
 	{
 		var source = string.Format(
 			Template,
-			$"double num = 0.133d; Xunit.Assert.Equal(0.13d, num, {precision});"
+			$"double num = 0.133d; Xunit.Assert.Equal(0.13d, num, {{|#0:{precision}|}});"
 		);
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(4, 61)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("[0..15]", "double");
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("[0..15]", "double");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -78,14 +73,9 @@ public async Task FindsError_ForDecimalArgumentWithPrecisionProvidedOutOfRange(i
 	{
 		var source = string.Format(
 			Template,
-			$"decimal num = 0.133m; Xunit.Assert.Equal(0.13m, num, {precision});"
+			$"decimal num = 0.133m; Xunit.Assert.Equal(0.13m, num, {{|#0:{precision}|}});"
 		);
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithLocation(4, 62)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("[0..28]", "decimal");
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("[0..28]", "decimal");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckTests.cs
index 23012129..73070478 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckTests.cs
@@ -1,41 +1,36 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertEqualShouldNotBeUsedForBoolLiteralCheck>;
 
 public class AssertEqualShouldNotBeUsedForBoolLiteralCheckTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		Constants.Asserts.Equal,
 		Constants.Asserts.NotEqual,
 		Constants.Asserts.StrictEqual,
 		Constants.Asserts.NotStrictEqual,
-	};
+	];
 
 	[Theory]
 	[InlineData(Constants.Asserts.Equal, Constants.Asserts.True)]
 	[InlineData(Constants.Asserts.StrictEqual, Constants.Asserts.True)]
 	[InlineData(Constants.Asserts.NotEqual, Constants.Asserts.False)]
 	[InlineData(Constants.Asserts.NotStrictEqual, Constants.Asserts.False)]
-	public async Task FindsWarning_ForFirstBoolLiteral(
+	public async Task ForFirstBoolLiteral_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        bool val = true;
-        Xunit.Assert.{method}(true, val);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 33 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        bool val = true;
+			        {{|#0:Xunit.Assert.{0}(true, val)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -43,68 +38,67 @@ void TestMethod() {{
 	[Theory]
 	[InlineData(Constants.Asserts.Equal, Constants.Asserts.False)]
 	[InlineData(Constants.Asserts.NotEqual, Constants.Asserts.True)]
-	public async Task FindsWarning_ForFirstBoolLiteral_WithCustomComparer(
+	public async Task ForFirstBoolLiteral_WithCustomComparer_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        bool val = false;
-        Xunit.Assert.{method}(false, val, System.Collections.Generic.EqualityComparer<bool>.Default);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 93 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        bool val = false;
+			        {{|#0:Xunit.Assert.{0}(false, val, System.Collections.Generic.EqualityComparer<bool>.Default)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForFirstBoolLiteral_ObjectOverload(string method)
+	public async Task ForFirstBoolLiteral_ObjectOverload_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        object val = false;
-        Xunit.Assert.{method}(true, val);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        object val = false;
+			        Xunit.Assert.{0}(true, val);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForOtherLiteral(string method)
+	public async Task ForOtherLiteral_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        int val = 1;
-        Xunit.Assert.{method}(1, val);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        int val = 1;
+			        Xunit.Assert.{0}(1, val);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForSecondBoolLiteral(string method)
+	public async Task ForSecondBoolLiteral_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        bool val = false;
-        Xunit.Assert.{method}(val, true);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        bool val = false;
+			        Xunit.Assert.{0}(val, true);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckTests.cs
index 2d8035ee..cae84524 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckTests.cs
@@ -1,19 +1,17 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertEqualShouldNotBeUsedForCollectionSizeCheck>;
 
 public class AssertEqualShouldNotBeUsedForCollectionSizeCheckTests
 {
-	public static TheoryData<string> AllowedCollections = new()
-	{
+	public static TheoryData<string> AllowedCollections =
+	[
 		"new System.ArraySegment<int>().Count",
 		"Microsoft.Extensions.Primitives.StringValues.Empty.Count",
-	};
-
-	public static TheoryData<string> DisallowedCollections = new()
-	{
+	];
+	public static TheoryData<string> DisallowedCollections =
+	[
 		"new int[0].Length",
 		"new System.Collections.ArrayList().Count",
 		"new System.Collections.Generic.List<int>().Count",
@@ -22,29 +20,29 @@ public class AssertEqualShouldNotBeUsedForCollectionSizeCheckTests
 		"new System.Collections.ObjectModel.Collection<int>().Count",
 		"new System.Collections.Generic.List<int>().AsReadOnly().Count",
 		"System.Linq.Enumerable.Empty<int>().Count()",
-	};
-
-	public static TheoryData<string> DisallowedCollectionInterfaces = new()
-	{
+	];
+	public static TheoryData<string> DisallowedCollectionInterfaces =
+	[
 		"ICollection",
 		"ICollection<string>",
 		"IReadOnlyCollection<string>",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(AllowedCollections))]
 	public async Task AllowedCollection_DoesNotTrigger(string collection)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.Equal(0, {collection});
-        Xunit.Assert.Equal(1, {collection});
-        Xunit.Assert.NotEqual(0, {collection});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Equal(0, {0});
+			        Xunit.Assert.Equal(1, {0});
+			        Xunit.Assert.NotEqual(0, {0});
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -55,16 +53,17 @@ void TestMethod() {{
 	public async Task AllowedCheck_DoesNotTrigger(string collection)
 	{
 		// Anything that's non-zero for Equal/NotEqual and non-one for Equal is allowed
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.Equal(2, {collection});
-        Xunit.Assert.NotEqual(1, {collection});
-        Xunit.Assert.NotEqual(2, {collection});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.Equal(2, {0});
+			        Xunit.Assert.NotEqual(1, {0});
+			        Xunit.Assert.NotEqual(2, {0});
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -74,33 +73,22 @@ void TestMethod() {{
 	[MemberData(nameof(DisallowedCollections))]
 	public async Task InvalidCheckWithConcreteType_Triggers(string collection)
 	{
-		var source = $@"
-using System.Linq;
-
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.Equal(0, {collection});
-        Xunit.Assert.Equal(1, {collection});
-        Xunit.Assert.NotEqual(0, {collection});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Linq;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.Equal(0, {0})|}};
+			        {{|#1:Xunit.Assert.Equal(1, {0})|}};
+			        {{|#2:Xunit.Assert.NotEqual(0, {0})|}};
+			    }}
+			}}
+			""", collection);
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(6, 9, 6, 32 + collection.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Empty),
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 9, 7, 32 + collection.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Single),
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 35 + collection.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
+			Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Equal()", Constants.Asserts.Empty),
+			Verify.Diagnostic().WithLocation(1).WithArguments("Assert.Equal()", Constants.Asserts.Single),
+			Verify.Diagnostic().WithLocation(2).WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
@@ -110,35 +98,24 @@ void TestMethod() {{
 	[MemberData(nameof(DisallowedCollectionInterfaces))]
 	public async Task InvalidCheckWithInterfaceType_Triggers(string @interface)
 	{
-		var source = $@"
-using System.Collections;
-using System.Collections.Generic;
-
-class TestClass {{
-    void TestMethod() {{
-        {@interface} collection = null;
-        Xunit.Assert.Equal(0, collection.Count);
-        Xunit.Assert.Equal(1, collection.Count);
-        Xunit.Assert.NotEqual(0, collection.Count);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+
+			class TestClass {{
+			    void TestMethod() {{
+			        {0} collection = null;
+			        {{|#0:Xunit.Assert.Equal(0, collection.Count)|}};
+			        {{|#1:Xunit.Assert.Equal(1, collection.Count)|}};
+			        {{|#2:Xunit.Assert.NotEqual(0, collection.Count)|}};
+			    }}
+			}}
+			""", @interface);
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 48)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Empty),
-			Verify
-				.Diagnostic()
-				.WithSpan(9, 9, 9, 48)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Single),
-			Verify
-				.Diagnostic()
-				.WithSpan(10, 9, 10, 51)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
+			Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Equal()", Constants.Asserts.Empty),
+			Verify.Diagnostic().WithLocation(1).WithArguments("Assert.Equal()", Constants.Asserts.Single),
+			Verify.Diagnostic().WithLocation(2).WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
@@ -147,47 +124,36 @@ void TestMethod() {{
 	[Fact]
 	public async Task InvalidCheckWithCustomNonGenericCollection_Triggers()
 	{
-		var source = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-class IntCollection : ICollection<int> {
-    public int Count { get { throw null; } }
-    public bool IsReadOnly { get { throw null; } }
-    public void Add(int item) { throw null; }
-    public void Clear() { throw null; }
-    public bool Contains(int item) { throw null; }
-    public void CopyTo(int[] array, int arrayIndex) { throw null; }
-    public IEnumerator<int> GetEnumerator() { throw null; }
-    public bool Remove(int item) { throw null; }
-    IEnumerator IEnumerable.GetEnumerator() { throw null; }
-}
-
-class TestClass {
-    void TestMethod() {
-        Assert.Equal(0, new IntCollection().Count);
-        Assert.Equal(1, new IntCollection().Count);
-        Assert.NotEqual(0, new IntCollection().Count);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			class IntCollection : ICollection<int> {
+			    public int Count { get { throw null; } }
+			    public bool IsReadOnly { get { throw null; } }
+			    public void Add(int item) { throw null; }
+			    public void Clear() { throw null; }
+			    public bool Contains(int item) { throw null; }
+			    public void CopyTo(int[] array, int arrayIndex) { throw null; }
+			    public IEnumerator<int> GetEnumerator() { throw null; }
+			    public bool Remove(int item) { throw null; }
+			    IEnumerator IEnumerable.GetEnumerator() { throw null; }
+			}
+
+			class TestClass {
+			    void TestMethod() {
+			        {|#0:Assert.Equal(0, new IntCollection().Count)|};
+			        {|#1:Assert.Equal(1, new IntCollection().Count)|};
+			        {|#2:Assert.NotEqual(0, new IntCollection().Count)|};
+			    }
+			}
+			""";
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(20, 9, 20, 51)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Empty),
-			Verify
-				.Diagnostic()
-				.WithSpan(21, 9, 21, 51)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.Equal()", Constants.Asserts.Single),
-			Verify
-				.Diagnostic()
-				.WithSpan(22, 9, 22, 54)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
+			Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Equal()", Constants.Asserts.Empty),
+			Verify.Diagnostic().WithLocation(1).WithArguments("Assert.Equal()", Constants.Asserts.Single),
+			Verify.Diagnostic().WithLocation(2).WithArguments("Assert.NotEqual()", Constants.Asserts.NotEmpty),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
@@ -196,41 +162,43 @@ void TestMethod() {
 	[Fact]
 	public async Task OverridingCountMethod_DoesNotTrigger()
 	{
-		var source = @"
-using System.Collections.Generic;
-
-interface IIntCollection : ICollection<int> {
-    new int Count { get; }
-}
-
-interface ICustomCollection<T> : ICollection<T> {
-    new int Count { get; }
-}
-
-interface ICustomDictionary<K, V> : ICollection<KeyValuePair<K, V>> {
-    new int Count { get; }
-}
-
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.Equal(1, ((IIntCollection)null).Count);
-        Xunit.Assert.Equal(1, ((ICustomCollection<int>)null).Count);
-        Xunit.Assert.Equal(1, ((ICustomDictionary<int, int>)null).Count);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			using System.Collections.Generic;
+
+			interface IIntCollection : ICollection<int> {
+			    new int Count { get; }
+			}
+
+			interface ICustomCollection<T> : ICollection<T> {
+			    new int Count { get; }
+			}
+
+			interface ICustomDictionary<K, V> : ICollection<KeyValuePair<K, V>> {
+			    new int Count { get; }
+			}
+
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.Equal(1, ((IIntCollection)null).Count);
+			        Xunit.Assert.Equal(1, ((ICustomCollection<int>)null).Count);
+			        Xunit.Assert.Equal(1, ((ICustomDictionary<int, int>)null).Count);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotCrash_ForNonIntArguments()
+	public async Task ForNonIntArguments_DoesNotCrash()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.Equal('b', new int[0].Length);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.Equal('b', new int[0].Length);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForNullCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForNullCheckTests.cs
index ddc4abf4..3d57fbfd 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForNullCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualShouldNotBeUsedForNullCheckTests.cs
@@ -1,20 +1,19 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertEqualShouldNotBeUsedForNullCheck>;
 
 public class AssertEqualShouldNotBeUsedForNullCheckTests
 {
-	public static TheoryData<string> Methods_All = new()
-	{
+	public static TheoryData<string> Methods_All =
+	[
 		Constants.Asserts.Equal,
 		Constants.Asserts.NotEqual,
 		Constants.Asserts.StrictEqual,
 		Constants.Asserts.NotStrictEqual,
 		Constants.Asserts.Same,
 		Constants.Asserts.NotSame,
-	};
+	];
 	public static TheoryData<string, string> Methods_Equal_WithReplacement = new()
 	{
 		{ Constants.Asserts.Equal, Constants.Asserts.Null },
@@ -23,46 +22,38 @@ public class AssertEqualShouldNotBeUsedForNullCheckTests
 
 	[Theory]
 	[MemberData(nameof(Methods_Equal_WithReplacement))]
-	public async Task FindsWarning_ForFirstNullLiteral_StringOverload(
+	public async Task ForFirstNullLiteral_StringOverload_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        string val = null;
-        Xunit.Assert.{method}(null, val);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 33 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        string val = null;
+			        {{|#0:Xunit.Assert.{0}(null, val)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_Equal_WithReplacement))]
-	public async Task FindsWarning_ForFirstNullLiteral_StringOverload_WithCustomComparer(
+	public async Task ForFirstNullLiteral_StringOverload_WithCustomComparer_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        string val = null;
-        Xunit.Assert.{method}(null, val, System.StringComparer.Ordinal);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 64 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        string val = null;
+			        {{|#0:Xunit.Assert.{0}(null, val, System.StringComparer.Ordinal)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -74,46 +65,38 @@ void TestMethod() {{
 	[InlineData(Constants.Asserts.NotEqual, Constants.Asserts.NotNull)]
 	[InlineData(Constants.Asserts.NotStrictEqual, Constants.Asserts.NotNull)]
 	[InlineData(Constants.Asserts.NotSame, Constants.Asserts.NotNull)]
-	public async Task FindsWarning_ForFirstNullLiteral_ObjectOverload(
+	public async Task ForFirstNullLiteral_ObjectOverload_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        object val = null;
-        Xunit.Assert.{method}(null, val);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 33 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        object val = null;
+			        {{|#0:Xunit.Assert.{0}(null, val)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_Equal_WithReplacement))]
-	public async Task FindsWarning_ForFirstNullLiteral_ObjectOverload_WithCustomComparer(
+	public async Task ForFirstNullLiteral_ObjectOverload_WithCustomComparer_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        object val = null;
-        Xunit.Assert.{method}(null, val, System.Collections.Generic.EqualityComparer<object>.Default);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 94 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        object val = null;
+			        {{|#0:Xunit.Assert.{0}(null, val, System.Collections.Generic.EqualityComparer<object>.Default)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -123,76 +106,70 @@ void TestMethod() {{
 	[InlineData(Constants.Asserts.NotEqual, Constants.Asserts.NotNull)]
 	[InlineData(Constants.Asserts.StrictEqual, Constants.Asserts.Null)]
 	[InlineData(Constants.Asserts.NotStrictEqual, Constants.Asserts.NotNull)]
-	public async Task FindsWarning_ForFirstNullLiteral_GenericOverload(
+	public async Task ForFirstNullLiteral_GenericOverload_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        TestClass val = null;
-        Xunit.Assert.{method}<TestClass>(null, val);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 44 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        TestClass val = null;
+			        {{|#0:Xunit.Assert.{0}<TestClass>(null, val)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_Equal_WithReplacement))]
-	public async Task FindsWarning_ForFirstNullLiteral_GenericOverload_WithCustomComparer(
+	public async Task ForFirstNullLiteral_GenericOverload_WithCustomComparer_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        TestClass val = null;
-        Xunit.Assert.{method}<TestClass>(null, val, System.Collections.Generic.EqualityComparer<TestClass>.Default);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 108 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        TestClass val = null;
+			        {{|#0:Xunit.Assert.{0}<TestClass>(null, val, System.Collections.Generic.EqualityComparer<TestClass>.Default)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_All))]
-	public async Task DoesNotFindWarning_ForOtherLiteral(string method)
+	public async Task ForOtherLiteral_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        int val = 1;
-        Xunit.Assert.{method}(1, val);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        int val = 1;
+			        Xunit.Assert.{0}(1, val);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_All))]
-	public async Task DoesNotFindWarning_ForSecondNullLiteral(string method)
+	public async Task ForSecondNullLiteral_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        string val = null;
-        Xunit.Assert.{method}(val, null);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        string val = null;
+			        Xunit.Assert.{0}(val, null);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualsShouldNotBeUsedTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualsShouldNotBeUsedTests.cs
index 57221740..63af1b09 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualsShouldNotBeUsedTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertEqualsShouldNotBeUsedTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertEqualsShouldNotBeUsed>;
@@ -9,28 +8,17 @@ public class AssertEqualsShouldNotBeUsedTests
 	[Theory]
 	[InlineData(nameof(object.Equals), Constants.Asserts.Equal)]
 	[InlineData(nameof(object.ReferenceEquals), Constants.Asserts.Same)]
-	public async Task FindsHiddenDiagnosticWhenProhibitedMethodIsUsed(
+	public async Task WhenProhibitedMethodIsUsed_Triggers(
 		string method,
 		string replacement)
 	{
 		var source = $@"
 class TestClass {{
     void TestMethod() {{
-        Xunit.Assert.{method}(null, null);
+        {{|#0:{{|CS0619:Xunit.Assert.{method}(null, null)|}}|}};
     }}
 }}";
-		var expected = new[]
-		{
-			Verify
-				.CompilerError("CS0619")
-				.WithSpan(4, 9, 4, 34 + method.Length)
-				.WithMessage($"'Assert.{method}(object, object)' is obsolete: 'This is an override of Object.{method}(). Call Assert.{replacement}() instead.'"),
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 34 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Hidden)
-				.WithArguments($"Assert.{method}()", replacement),
-		};
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeTests.cs
index 00b37865..c900f1ac 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertIsTypeShouldNotBeUsedForAbstractType>;
 
@@ -13,93 +12,82 @@ public class AssertIsTypeShouldNotBeUsedForAbstractTypeTests
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsError_Interface(
+	public async Task Interface_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-using System;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-class TestClass {{
-    void TestMethod() {{
-        Assert.{method}<IDisposable>(new object());
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 9, 7, 43 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("interface", "System.IDisposable", replacement);
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Assert.{0}<IDisposable>(new object())|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("interface", "System.IDisposable", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsError_AbstractClass(
+	public async Task AbstractClass_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-using System.IO;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System.IO;
+			using Xunit;
 
-class TestClass {{
-    void TestMethod() {{
-        Assert.{method}<Stream>(new object());
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 9, 7, 38 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("abstract class", "System.IO.Stream", replacement);
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Assert.{0}<Stream>(new object())|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("abstract class", "System.IO.Stream", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsError_UsingStatic(
+	public async Task UsingStatic_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-using System;
-using static Xunit.Assert;
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using static Xunit.Assert;
 
-class TestClass {{
-    void TestMethod() {{
-        {method}<IDisposable>(new object());
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(7, 9, 7, 36 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("interface", "System.IDisposable", replacement);
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:{0}<IDisposable>(new object())|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("interface", "System.IDisposable", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindError_NonAbstractClass(
+	public async Task NonAbstractClass_DoesNotTrigger(
 		string method,
 		string _)
 	{
-		var source = $@"
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-class TestClass {{
-    void TestMethod() {{
-        Assert.{method}<string>(new object());
-    }}
-}}";
+			class TestClass {{
+			    void TestMethod() {{
+			        Assert.{0}<string>(new object());
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTests.cs
index 2e9bd5a5..4cb58fae 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTests.cs
@@ -1,47 +1,43 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertIsTypeShouldUseGenericOverloadType>;
 
 public class AssertIsTypeShouldUseGenericOverloadTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		"IsType",
 		"IsNotType",
 		"IsAssignableFrom",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsWarning_ForNonGenericCall(string method)
+	public async Task ForNonGenericCall_Triggers(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(typeof(int), 1);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 38 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("int");
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(typeof(int), 1)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("int");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForGenericCall(string method)
+	public async Task ForGenericCall_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}<int>(1);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}<int>(1);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTypeTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTypeTests.cs
index d1789150..fcd81f40 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTypeTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertIsTypeShouldUseGenericOverloadTypeTests.cs
@@ -1,4 +1,4 @@
-#if NETCOREAPP && ROSLYN_4_4_OR_GREATER  // Static abstract methods are only supported on .NET with C# 11
+#if NETCOREAPP
 
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CSharp;
@@ -9,33 +9,36 @@ public class AssertIsTypeShouldUseGenericOverloadTypeTests
 {
 	public class StaticAbstractInterfaceMethods
 	{
-		const string methodCode = "static abstract void Method();";
-		const string codeTemplate = @"
-using Xunit;
+#if ROSLYN_4_4_OR_GREATER  // Static abstract methods are only supported on .NET with C# 11
+
+		const string methodCode = /* lang=c#-test */ "static abstract void Method();";
+		const string codeTemplate = /* lang=c#-test */ """
+			using Xunit;
 
-public interface IParentClass  {{
-	{0}
-}}
+			public interface IParentClass  {{
+				{0}
+			}}
 
-public interface IClass : IParentClass {{
-    {1}
-}}
+			public interface IClass : IParentClass {{
+			    {1}
+			}}
 
-public class Class : IClass {{
-    public static void Method() {{ }}
-}}
+			public class Class : IClass {{
+			    public static void Method() {{ }}
+			}}
 
-public abstract class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = new Class();
+			public abstract class TestClass {{
+			    [Fact]
+			    public void TestMethod() {{
+			        var data = new Class();
 
-        Assert.IsAssignableFrom(typeof(IClass), data);
-    }}
-}}";
+			        Assert.IsAssignableFrom(typeof(IClass), data);
+			    }}
+			}}
+			""";
 
 		[Fact]
-		public async Task DoesNotFindWarning_ForStaticAbstractInterfaceMembers()
+		public async Task ForStaticAbstractInterfaceMembers_DoesNotTrigger()
 		{
 			string source = string.Format(codeTemplate, string.Empty, methodCode);
 
@@ -43,43 +46,44 @@ public async Task DoesNotFindWarning_ForStaticAbstractInterfaceMembers()
 		}
 
 		[Fact]
-		public async Task DoesNotFindWarning_ForNestedStaticAbstractInterfaceMembers()
+		public async Task ForNestedStaticAbstractInterfaceMembers_DoesNotTrigger()
 		{
 			string source = string.Format(codeTemplate, methodCode, string.Empty);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp11, source);
 		}
 
+#endif
+
 		[Theory]
 		[InlineData("static", "", "{ }")]
 		[InlineData("", "abstract", ";")]
-		public async Task FindsWarning_ForNotStaticAbstractInterfaceMembers(string staticModifier, string abstractModifier, string methodBody)
+		public async Task ForNotStaticAbstractInterfaceMembers_Triggers(
+			string staticModifier,
+			string abstractModifier,
+			string methodBody)
 		{
-			string source = $@"
-using Xunit;
-
-public interface IClass {{
-    {staticModifier} {abstractModifier} void Method() {methodBody}
-}}
-
-public class Class : IClass {{
-    public {staticModifier} void Method() {{ }}
-}}
-
-public abstract class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = new Class();
-
-        Assert.IsAssignableFrom(typeof(IClass), data);
-    }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic()
-					.WithSpan(17, 9, 17, 54)
-					.WithArguments("IClass");
+			string source = string.Format(/* lang=c#-test */ """
+				using Xunit;
+
+				public interface IClass {{
+				    {0} {1} void Method() {2}
+				}}
+
+				public class Class : IClass {{
+				    public {0} void Method() {{ }}
+				}}
+
+				public abstract class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var data = new Class();
+
+				        {{|#0:Assert.IsAssignableFrom(typeof(IClass), data)|}};
+				    }}
+				}}
+				""", staticModifier, abstractModifier, methodBody);
+			var expected = Verify.Diagnostic().WithLocation(0).WithArguments("IClass");
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
 		}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertNullShouldNotBeCalledOnValueTypesTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertNullShouldNotBeCalledOnValueTypesTests.cs
index 39bc9914..859cd2e9 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertNullShouldNotBeCalledOnValueTypesTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertNullShouldNotBeCalledOnValueTypesTests.cs
@@ -1,111 +1,111 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertNullShouldNotBeCalledOnValueTypes>;
 
 public class AssertNullShouldNotBeCalledOnValueTypesTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		"Null",
 		"NotNull",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsWarning_ForValueType(string method)
+	public async Task ForValueType_Triggers(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        int val = 1;
-        Xunit.Assert.{method}(val);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 27 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int");
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        int val = 1;
+			        {{|#0:Xunit.Assert.{0}(val)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int");
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForNullableValueType(string method)
+	public async Task ForNullableValueType_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        int? val = 1;
-        Xunit.Assert.{method}(val);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        int? val = 1;
+			        Xunit.Assert.{0}(val);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForNullableReferenceType(string method)
+	public async Task ForNullableReferenceType_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        string val = null;
-        Xunit.Assert.{method}(val);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        string val = null;
+			        Xunit.Assert.{0}(val);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForClassConstrainedGenericTypes(string method)
+	public async Task ForClassConstrainedGenericTypes_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class Class<T> where T : class {{
-    public void Method(T arg) {{
-        Xunit.Assert.{method}(arg);
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class Class<T> where T : class {{
+			    public void Method(T arg) {{
+			        Xunit.Assert.{0}(arg);
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForInterfaceConstrainedGenericTypes(string method)
+	public async Task ForInterfaceConstrainedGenericTypes_DoesNotTrigger(string method)
 	{
-		var source = $@"
-interface IDo {{ }}
-
-class Class<T> where T : IDo {{
-    public void Method(System.Collections.Generic.IEnumerable<T> collection) {{
-        foreach (T item in collection) {{
-            Xunit.Assert.{method}(item);
-        }}
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			interface IDo {{ }}
+
+			class Class<T> where T : IDo {{
+			    public void Method(System.Collections.Generic.IEnumerable<T> collection) {{
+			        foreach (T item in collection) {{
+			            Xunit.Assert.{0}(item);
+			        }}
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForUnconstrainedGenericTypes(string method)
+	public async Task ForUnconstrainedGenericTypes_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class Class<T> {{
-    public void Method(System.Collections.Generic.IEnumerable<T> collection) {{
-        foreach (T item in collection) {{
-            Xunit.Assert.{method}(item);
-        }}
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class Class<T> {{
+			    public void Method(System.Collections.Generic.IEnumerable<T> collection) {{
+			        foreach (T item in collection) {{
+			            Xunit.Assert.{0}(item);
+			        }}
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -113,31 +113,26 @@ public void Method(System.Collections.Generic.IEnumerable<T> collection) {{
 	[Theory]
 	[MemberData(nameof(Methods))]
 	// https://github.com/xunit/xunit/issues/2395
-	public async Task DoesNotFindWarning_ForUserDefinedImplicitConversion(string method)
+	public async Task ForUserDefinedImplicitConversion_DoesNotTrigger(string method)
 	{
-		var source = $@"
-public class TestClass
-{{
-    public void TestMethod()
-    {{
-        Xunit.Assert.{method}((MyBuggyInt)42);
-        Xunit.Assert.{method}((MyBuggyInt)(int?)42);
-        Xunit.Assert.{method}((MyBuggyIntBase)42);
-        Xunit.Assert.{method}((MyBuggyIntBase)(int?)42);
-    }}
-}}
-
-public abstract class MyBuggyIntBase
-{{
-    public static implicit operator MyBuggyIntBase(int i) => new MyBuggyInt();
-}}
-
-public class MyBuggyInt : MyBuggyIntBase
-{{
-    public MyBuggyInt()
-	{{
-	}}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    public void TestMethod() {{
+			        Xunit.Assert.{0}((MyBuggyInt)42);
+			        Xunit.Assert.{0}((MyBuggyInt)(int?)42);
+			        Xunit.Assert.{0}((MyBuggyIntBase)42);
+			        Xunit.Assert.{0}((MyBuggyIntBase)(int?)42);
+			    }}
+			}}
+
+			public abstract class MyBuggyIntBase {{
+			    public static implicit operator MyBuggyIntBase(int i) => new MyBuggyInt();
+			}}
+
+			public class MyBuggyInt : MyBuggyIntBase {{
+			    public MyBuggyInt() {{ }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckTests.cs
index 9e9ea69a..3f5982b4 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertRegexMatchShouldNotUseBoolLiteralCheck>;
@@ -14,67 +13,55 @@ public class AssertRegexMatchShouldNotUseBoolLiteralCheckTests
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarning_ForStaticRegexIsMatch(
+	public async Task ForStaticRegexIsMatch_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(System.Text.RegularExpressions.Regex.IsMatch(""abc"", ""\\w*""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 83 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(System.Text.RegularExpressions.Regex.IsMatch("abc", "\\w*"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarning_ForInstanceRegexIsMatchWithInlineConstructedRegex(
+	public async Task ForInstanceRegexIsMatchWithInlineConstructedRegex_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(new System.Text.RegularExpressions.Regex(""abc"").IsMatch(""\\w*""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 87 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(new System.Text.RegularExpressions.Regex("abc").IsMatch("\\w*"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarning_ForInstanceRegexIsMatchWithConstructedRegexVariable(
+	public async Task ForInstanceRegexIsMatchWithConstructedRegexVariable_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        var regex = new System.Text.RegularExpressions.Regex(""abc"");
-        Xunit.Assert.{method}(regex.IsMatch(""\\w*""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 45 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        var regex = new System.Text.RegularExpressions.Regex("abc");
+			        {{|#0:Xunit.Assert.{0}(regex.IsMatch("\\w*"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSameShouldNotBeCalledOnValueTypesTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSameShouldNotBeCalledOnValueTypesTests.cs
index 7c3af4d0..9ecf363d 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSameShouldNotBeCalledOnValueTypesTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSameShouldNotBeCalledOnValueTypesTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertSameShouldNotBeCalledOnValueTypes>;
@@ -14,69 +13,57 @@ public class AssertSameShouldNotBeCalledOnValueTypesTests
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarningForTwoValueParameters(
+	public async Task TwoValueParameters_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        int a = 0;
-        Xunit.Assert.{method}(0, a);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 28 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        int a = 0;
+			        {{|#0:Xunit.Assert.{0}(0, a)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarningForFirstValueParameters(
+	public async Task FirstValueParameters_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        object a = 0;
-        Xunit.Assert.{method}(0, a);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 28 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        object a = 0;
+			        {{|#0:Xunit.Assert.{0}(0, a)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarningForSecondValueParameters(
+	public async Task SecondValueParameters_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        object a = 0;
-        Xunit.Assert.{method}(a, 0);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 28 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        object a = 0;
+			        {{|#0:Xunit.Assert.{0}(a, 0)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -84,86 +71,71 @@ void TestMethod() {{
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
 	// https://github.com/xunit/xunit/issues/2395
-	public async Task DoesNotFindWarningForUserDefinedImplicitConversion(
+	public async Task UserDefinedImplicitConversion_DoesNotTrigger(
 		string method,
-		string replacement)
+		string _)
 	{
-		_ = replacement; // Verifies that diagnostic is not issued, so the replacement method is not needed
-
-		var source = $@"
-public class TestClass
-{{
-    public void TestMethod()
-    {{
-        var o = new object();
-
-        Xunit.Assert.{method}((MyBuggyInt)42, o);
-        Xunit.Assert.{method}((MyBuggyInt)(int?)42, o);
-        Xunit.Assert.{method}((MyBuggyIntBase)42, o);
-        Xunit.Assert.{method}((MyBuggyIntBase)(int?)42, o);
-
-        Xunit.Assert.{method}(o, (MyBuggyInt)42);
-        Xunit.Assert.{method}(o, (MyBuggyInt)(int?)42);
-        Xunit.Assert.{method}(o, (MyBuggyIntBase)42);
-        Xunit.Assert.{method}(o, (MyBuggyIntBase)(int?)42);
-    }}
-}}
-
-public abstract class MyBuggyIntBase
-{{
-    public static implicit operator MyBuggyIntBase(int i) => new MyBuggyInt();
-}}
-
-public class MyBuggyInt : MyBuggyIntBase
-{{
-    public MyBuggyInt()
-    {{
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			public class TestClass {{
+			    public void TestMethod() {{
+			        var o = new object();
+
+			        Xunit.Assert.{0}((MyBuggyInt)42, o);
+			        Xunit.Assert.{0}((MyBuggyInt)(int?)42, o);
+			        Xunit.Assert.{0}((MyBuggyIntBase)42, o);
+			        Xunit.Assert.{0}((MyBuggyIntBase)(int?)42, o);
+
+			        Xunit.Assert.{0}(o, (MyBuggyInt)42);
+			        Xunit.Assert.{0}(o, (MyBuggyInt)(int?)42);
+			        Xunit.Assert.{0}(o, (MyBuggyIntBase)42);
+			        Xunit.Assert.{0}(o, (MyBuggyIntBase)(int?)42);
+			    }}
+			}}
+
+			public abstract class MyBuggyIntBase {{
+			    public static implicit operator MyBuggyIntBase(int i) => new MyBuggyInt();
+			}}
+
+			public class MyBuggyInt : MyBuggyIntBase {{
+			    public MyBuggyInt() {{ }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarningForFirstValueParametersIfSecondIsNull(
+	public async Task FirstValueParametersIfSecondIsNull_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(0, null);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 31 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(0, null)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarningForSecondValueParametersIfFirstIsNull(
+	public async Task SecondValueParametersIfFirstIsNull_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(null, 0);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 31 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", "int", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(null, 0)|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", "int", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSingleShouldBeUsedForSingleParameterTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSingleShouldBeUsedForSingleParameterTests.cs
index 56f18384..cdba147f 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSingleShouldBeUsedForSingleParameterTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSingleShouldBeUsedForSingleParameterTests.cs
@@ -9,24 +9,20 @@ public class AssertSingleShouldBeUsedForSingleParameterTests
 #if NETCOREAPP3_0_OR_GREATER
 	[InlineData("default(IAsyncEnumerable<int>)")]
 #endif
-	public async Task FindsInfo_ForSingleItemCollectionCheck(string collection)
+	public async Task ForSingleItemCollectionCheck_Triggers(string collection)
 	{
-		var code = @$"
-using Xunit;
-using System.Collections.Generic;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        Assert.Collection({collection}, item => Assert.NotNull(item));
-    }}
-}}";
+		var code = string.Format(/* lang=c#-test */ """
+			using Xunit;
+			using System.Collections.Generic;
 
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 58 + collection.Length)
-				.WithArguments("Collection");
+			public class TestClass {{
+			    [Fact]
+			    public void TestMethod() {{
+			        {{|#0:Assert.Collection({0}, item => Assert.NotNull(item))|}};
+			    }}
+			}}
+			""", collection);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Collection");
 
 		await Verify.VerifyAnalyzer(code, expected);
 	}
@@ -36,18 +32,19 @@ public void TestMethod() {{
 #if NETCOREAPP3_0_OR_GREATER
 	[InlineData("default(IAsyncEnumerable<int>)")]
 #endif
-	public async Task DoesNotFindInfo_ForMultipleItemCollectionCheck(string collection)
+	public async Task ForMultipleItemCollectionCheck_DoesNotTrigger(string collection)
 	{
-		var code = @$"
-using Xunit;
-using System.Collections.Generic;
+		var code = string.Format(/* lang=c#-test */ """
+			using Xunit;
+			using System.Collections.Generic;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        Assert.Collection({collection}, item1 => Assert.NotNull(item1), item2 => Assert.NotNull(item2));
-    }}
-}}";
+			public class TestClass {{
+			    [Fact]
+			    public void TestMethod() {{
+			        Assert.Collection({0}, item1 => Assert.NotNull(item1), item2 => Assert.NotNull(item2));
+			    }}
+			}}
+			""", collection);
 
 		await Verify.VerifyAnalyzer(code);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckTest.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckTest.cs
index 59b0631c..5e4967a7 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckTest.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckTest.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertStringEqualityCheckShouldNotUseBoolCheck>;
@@ -12,164 +11,152 @@ public class AssertStringEqualityCheckShouldNotUseBoolCheckTest
 		{ Constants.Asserts.True, Constants.Asserts.Equal },
 		{ Constants.Asserts.False, Constants.Asserts.NotEqual },
 	};
-	public static TheoryData<StringComparison> SupportedStringComparisons = new()
-	{
+	public static TheoryData<StringComparison> SupportedStringComparisons =
+	[
 		StringComparison.Ordinal,
 		StringComparison.OrdinalIgnoreCase,
-	};
-	public static TheoryData<StringComparison> UnsupportedStringComparisons = new()
-	{
+	];
+	public static TheoryData<StringComparison> UnsupportedStringComparisons =
+	[
 		StringComparison.CurrentCulture,
 		StringComparison.CurrentCultureIgnoreCase,
 		StringComparison.InvariantCulture,
 		StringComparison.InvariantCultureIgnoreCase,
-	};
-	public static TheoryData<StringComparison> AllStringComparisons = new()
-	{
+	];
+	public static TheoryData<StringComparison> AllStringComparisons =
+	[
 		StringComparison.Ordinal,
 		StringComparison.OrdinalIgnoreCase,
 		StringComparison.CurrentCulture,
 		StringComparison.CurrentCultureIgnoreCase,
 		StringComparison.InvariantCulture,
 		StringComparison.InvariantCultureIgnoreCase,
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarning_ForInstanceEqualsCheck(
+	public async Task ForInstanceEqualsCheck_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".Equals(""a""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 41 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}("abc".Equals("a"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(SupportedStringComparisons))]
-	public async Task FindsWarning_ForTrueInstanceEqualsCheck_WithSupportedStringComparison(StringComparison comparison)
+	public async Task ForTrueInstanceEqualsCheck_WithSupportedStringComparison_Triggers(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True(""abc"".Equals(""a"", System.StringComparison.{comparison}));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 71 + comparison.ToString().Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.Equal);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.True("abc".Equals("a", System.StringComparison.{0}))|}};
+			    }}
+			}}
+			""", comparison);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.Equal);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(UnsupportedStringComparisons))]
-	public async Task DoesNotFindWarning_ForTrueInstanceEqualsCheck_WithUnsupportedStringComparison(StringComparison comparison)
+	public async Task ForTrueInstanceEqualsCheck_WithUnsupportedStringComparison_DoesNotTrigger(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True(""abc"".Equals(""a"", System.StringComparison.{comparison}));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.True("abc".Equals("a", System.StringComparison.{0}));
+			    }}
+			}}
+			""", comparison);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(AllStringComparisons))]
-	public async Task DoesNotFindWarning_ForFalseInstanceEqualsCheck_WithStringComparison(StringComparison comparison)
+	public async Task ForFalseInstanceEqualsCheck_WithStringComparison_DoesNotTrigger(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False(""abc"".Equals(""a"", System.StringComparison.{comparison}));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.False("abc".Equals("a", System.StringComparison.{0}));
+			    }}
+			}}
+			""", comparison);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods_WithReplacement))]
-	public async Task FindsWarning_ForStaticEqualsCheck(
+	public async Task ForStaticEqualsCheck_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(System.String.Equals(""abc"", ""a""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 56 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(System.String.Equals("abc", "a"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(SupportedStringComparisons))]
-	public async Task FindsWarning_ForTrueStaticEqualsCheck_WithSupportedStringComparison(StringComparison comparison)
+	public async Task ForTrueStaticEqualsCheck_WithSupportedStringComparison_Triggers(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True(System.String.Equals(""abc"", ""a"", System.StringComparison.{comparison}));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 86 + comparison.ToString().Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.Equal);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.True(System.String.Equals("abc", "a", System.StringComparison.{0}))|}};
+			    }}
+			}}
+			""", comparison);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.Equal);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(UnsupportedStringComparisons))]
-	public async Task DoesNotFindWarning_ForTrueStaticEqualsCheck_WithUnsupportedStringComparison(StringComparison comparison)
+	public async Task ForTrueStaticEqualsCheck_WithUnsupportedStringComparison_DoesNotTrigger(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.True(System.String.Equals(""abc"", ""a"", System.StringComparison.{comparison}));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.True(System.String.Equals("abc", "a", System.StringComparison.{0}));
+			    }}
+			}}
+			""", comparison);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(AllStringComparisons))]
-	public async Task DoesNotFindWarning_ForFalseStaticEqualsCheck_WithStringComparison(StringComparison comparison)
+	public async Task ForFalseStaticEqualsCheck_WithStringComparison_DoesNotTrigger(StringComparison comparison)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.False(System.String.Equals(""abc"", ""a"", System.StringComparison.{comparison}));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.False(System.String.Equals("abc", "a", System.StringComparison.{0}));
+			    }}
+			}}
+			""", comparison);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSubstringCheckShouldNotUseBoolCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSubstringCheckShouldNotUseBoolCheckTests.cs
index a95cd007..b452cbe9 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertSubstringCheckShouldNotUseBoolCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertSubstringCheckShouldNotUseBoolCheckTests.cs
@@ -1,290 +1,282 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertSubstringCheckShouldNotUseBoolCheck>;
 
 public class AssertSubstringCheckShouldNotUseBoolCheckTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		Constants.Asserts.True,
 		Constants.Asserts.False,
-	};
+	];
 
 	[Theory]
 	[InlineData(Constants.Asserts.True, Constants.Asserts.Contains)]
 	[InlineData(Constants.Asserts.False, Constants.Asserts.DoesNotContain)]
-	public async Task FindsWarning_ForBooleanContainsCheck(
+	public async Task ForBooleanContainsCheck_Triggers(
 		string method,
 		string replacement)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".Contains(""a""));
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 43 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments($"Assert.{method}()", replacement);
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}("abc".Contains("a"))|}};
+			    }}
+			}}
+			""", method);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments($"Assert.{method}()", replacement);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanContainsCheck_WithUserMessage(string method)
+	public async Task ForBooleanContainsCheck_WithUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".Contains(""a""), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".Contains("a"), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ForBooleanTrueStartsWithCheck()
+	public async Task ForBooleanTrueStartsWithCheck_Triggers()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.True(""abc"".StartsWith(""a""));
-    }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 49)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.StartsWith);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        {|#0:Xunit.Assert.True("abc".StartsWith("a"))|};
+			    }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.StartsWith);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ForBooleanTrueStartsWithCheck_WithStringComparison()
+	public async Task ForBooleanTrueStartsWithCheck_WithStringComparison_Triggers()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.True(""abc"".StartsWith(""a"", System.StringComparison.CurrentCulture));
-    }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 89)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.StartsWith);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        {|#0:Xunit.Assert.True("abc".StartsWith("a", System.StringComparison.CurrentCulture))|};
+			    }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.StartsWith);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForBooleanFalseStartsWithCheck()
+	public async Task ForBooleanFalseStartsWithCheck_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.False(""abc"".StartsWith(""a""));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.False("abc".StartsWith("a"));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForBooleanFalseStartsWithCheck_WithStringComparison()
+	public async Task ForBooleanFalseStartsWithCheck_WithStringComparison_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.False(""abc"".StartsWith(""a"", System.StringComparison.CurrentCulture));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.False("abc".StartsWith("a", System.StringComparison.CurrentCulture));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanStartsWithCheck_WithUserMessage(string method)
+	public async Task ForBooleanStartsWithCheck_WithUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".StartsWith(""a""), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".StartsWith("a"), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanStartsWithCheck_WithStringComparison_AndUserMessage(string method)
+	public async Task ForBooleanStartsWithCheck_WithStringComparison_AndUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".StartsWith(""a"", System.StringComparison.CurrentCulture), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".StartsWith("a", System.StringComparison.CurrentCulture), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanStartsWithCheck_WithBoolAndCulture(string method)
+	public async Task ForBooleanStartsWithCheck_WithBoolAndCulture_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".StartsWith(""a"", true, System.Globalization.CultureInfo.CurrentCulture));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".StartsWith("a", true, System.Globalization.CultureInfo.CurrentCulture));
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanStartsWithCheck_WithBoolAndCulture_AndUserMessage(string method)
+	public async Task ForBooleanStartsWithCheck_WithBoolAndCulture_AndUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".StartsWith(""a"", true, System.Globalization.CultureInfo.CurrentCulture), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".StartsWith("a", true, System.Globalization.CultureInfo.CurrentCulture), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ForBooleanTrueEndsWithCheck()
+	public async Task ForBooleanTrueEndsWithCheck_Triggers()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.True(""abc"".EndsWith(""a""));
-    }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 47)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.EndsWith);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        {|#0:Xunit.Assert.True("abc".EndsWith("a"))|};
+			    }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.EndsWith);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task FindsWarning_ForBooleanTrueEndsWithCheck_WithStringComparison()
+	public async Task ForBooleanTrueEndsWithCheck_WithStringComparison_Triggers()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.True(""abc"".EndsWith(""a"", System.StringComparison.CurrentCulture));
-    }
-}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 87)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Assert.True()", Constants.Asserts.EndsWith);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        {|#0:Xunit.Assert.True("abc".EndsWith("a", System.StringComparison.CurrentCulture))|};
+			    }
+			}
+			""";
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.True()", Constants.Asserts.EndsWith);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForBooleanFalseEndsWithCheck()
+	public async Task ForBooleanFalseEndsWithCheck_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.False(""abc"".EndsWith(""a""));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.False("abc".EndsWith("a"));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForBooleanFalseEndsWithCheck_WithStringComparison()
+	public async Task ForBooleanFalseEndsWithCheck_WithStringComparison_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.False(""abc"".EndsWith(""a"", System.StringComparison.CurrentCulture));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        Xunit.Assert.False("abc".EndsWith("a", System.StringComparison.CurrentCulture));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanEndsWithCheck_WithUserMessage(string method)
+	public async Task ForBooleanEndsWithCheck_WithUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".EndsWith(""a""), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".EndsWith("a"), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanEndsWithCheck_WithStringComparison_AndUserMessage(string method)
+	public async Task ForBooleanEndsWithCheck_WithStringComparison_AndUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".EndsWith(""a"", System.StringComparison.CurrentCulture), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".EndsWith("a", System.StringComparison.CurrentCulture), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanEndsWithCheck_WithBoolAndCulture(string method)
+	public async Task ForBooleanEndsWithCheck_WithBoolAndCulture_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".EndsWith(""a"", true, System.Globalization.CultureInfo.CurrentCulture));
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".EndsWith("a", true, System.Globalization.CultureInfo.CurrentCulture));
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task DoesNotFindWarning_ForBooleanEndsWithCheck_WithBoolAndCulture_AndUserMessage(string method)
+	public async Task ForBooleanEndsWithCheck_WithBoolAndCulture_AndUserMessage_DoesNotTrigger(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(""abc"".EndsWith(""a"", true, System.Globalization.CultureInfo.CurrentCulture), ""message"");
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        Xunit.Assert.{0}("abc".EndsWith("a", true, System.Globalization.CultureInfo.CurrentCulture), "message");
+			    }}
+			}}
+			""", method);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckTests.cs
index b9f7113a..ddbf2b5d 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckTests.cs
@@ -1,268 +1,233 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.Testing;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.AssertThrowsShouldNotBeUsedForAsyncThrowsCheck>;
 
 public class AssertThrowsShouldNotBeUsedForAsyncThrowsCheckTests
 {
-	public static TheoryData<string> NonAsyncLambdas = new()
-	{
+	public static TheoryData<string> NonAsyncLambdas =
+	[
 		"ThrowingMethod",
 		"() => 1",
-	};
+	];
 
-	public static TheoryData<string> AsyncLambdas = new()
-	{
+	public static TheoryData<string> AsyncLambdas =
+	[
 		"(System.Func<System.Threading.Tasks.Task>)ThrowingMethod",
 		"() => System.Threading.Tasks.Task.Delay(0)",
 		"(System.Func<System.Threading.Tasks.Task>)(async () => await System.Threading.Tasks.Task.Delay(0))",
 		"(System.Func<System.Threading.Tasks.Task>)(async () => await System.Threading.Tasks.Task.Delay(0).ConfigureAwait(false))",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(NonAsyncLambdas))]
-	public async Task Throws_NonGeneric_WithNonAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task Throws_NonGeneric_WithNonAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Action ThrowingMethod = () => {{
-        throw new System.NotImplementedException();
-    }};
-
-    void TestMethod() {{
-        Xunit.Assert.Throws(typeof(System.NotImplementedException), {lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Action ThrowingMethod = () => {{
+			        throw new System.NotImplementedException();
+			    }};
+
+			    void TestMethod() {{
+			        Xunit.Assert.Throws(typeof(System.NotImplementedException), {0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(NonAsyncLambdas))]
-	public async Task Throws_Generic_WithNonAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task Throws_Generic_WithNonAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Action ThrowingMethod = () => {{
-        throw new System.NotImplementedException();
-    }};
-
-    void TestMethod() {{
-        Xunit.Assert.Throws<System.NotImplementedException>({lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Action ThrowingMethod = () => {{
+			        throw new System.NotImplementedException();
+			    }};
+
+			    void TestMethod() {{
+			        Xunit.Assert.Throws<System.NotImplementedException>({0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(NonAsyncLambdas))]
-	public async Task Throws_Generic_WithNamedArgumentException_WithNonAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task Throws_Generic_WithNamedArgumentException_WithNonAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Action ThrowingMethod = () => {{
-        throw new System.NotImplementedException();
-    }};
-
-    void TestMethod() {{
-        Xunit.Assert.Throws<System.ArgumentException>(""param1"", {lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Action ThrowingMethod = () => {{
+			        throw new System.NotImplementedException();
+			    }};
+
+			    void TestMethod() {{
+			        Xunit.Assert.Throws<System.ArgumentException>("param1", {0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task Throws_NonGeneric_WithAsyncLambda_FindsDiagnostic(string lambda)
+	public async Task Throws_NonGeneric_WithAsyncLambda_Triggers(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-		throw new System.NotImplementedException();
-    }}
-
-    void TestMethod() {{
-        Xunit.Assert.Throws(typeof(System.NotImplementedException), {lambda});
-    }}
-}}";
-		var expected = new[]
-		{
-			DiagnosticResult
-				.CompilerError("CS0619")
-				.WithSpan(8, 9, 8, 70 + lambda.Length)
-				.WithArguments("Xunit.Assert.Throws(System.Type, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync (and await the result) when testing async code."),
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 70 + lambda.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync),
-		};
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+					throw new System.NotImplementedException();
+			    }}
+
+			    void TestMethod() {{
+			        {{|#0:{{|CS0619:Xunit.Assert.Throws(typeof(System.NotImplementedException), {0})|}}|}};
+			    }}
+			}}
+			""", lambda);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task Throws_Generic_WithAsyncLambda_FindsDiagnostic(string lambda)
+	public async Task Throws_Generic_WithAsyncLambda_Triggers(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    void TestMethod() {{
-        Xunit.Assert.Throws<System.NotImplementedException>({lambda});
-    }}
-}}";
-		var expected = new[]
-		{
-			Verify
-				.CompilerError("CS0619")
-				.WithSpan(8, 9, 8, 62 + lambda.Length)
-				.WithMessage("'Assert.Throws<T>(Func<Task>)' is obsolete: 'You must call Assert.ThrowsAsync<T> (and await the result) when testing async code.'"),
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 62 + lambda.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync),
-		};
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    void TestMethod() {{
+			        {{|#0:{{|CS0619:Xunit.Assert.Throws<System.NotImplementedException>({0})|}}|}};
+			    }}
+			}}
+			""", lambda);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task Throws_Generic_WithNamedArgumentException_WithAsyncLambda_FindsDiagnostic(string lambda)
+	public async Task Throws_Generic_WithNamedArgumentException_WithAsyncLambda_Triggers(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    void TestMethod() {{
-        Xunit.Assert.Throws<System.ArgumentException>(""param1"", {lambda});
-    }}
-}}";
-		var expected = new[]
-		{
-			Verify
-				.CompilerError("CS0619")
-				.WithSpan(8, 9, 8, 66 + lambda.Length)
-				.WithArguments("Xunit.Assert.Throws<T>(string?, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync<T> (and await the result) when testing async code."),
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 66 + lambda.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync),
-		};
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    void TestMethod() {{
+			        {{|#0:{{|CS0619:Xunit.Assert.Throws<System.ArgumentException>("param1", {0})|}}|}};
+			    }}
+			}}
+			""", lambda);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.Throws()", Constants.Asserts.ThrowsAsync);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task ThrowsAsync_NonGeneric_WithAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task ThrowsAsync_NonGeneric_WithAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    async System.Threading.Tasks.Task TestMethod() {{
-        await Xunit.Assert.ThrowsAsync(typeof(System.NotImplementedException), {lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    async System.Threading.Tasks.Task TestMethod() {{
+			        await Xunit.Assert.ThrowsAsync(typeof(System.NotImplementedException), {0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task ThrowsAsync_Generic_WithAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task ThrowsAsync_Generic_WithAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    async void TestMethod() {{
-        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>({lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    async void TestMethod() {{
+			        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>({0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(NonAsyncLambdas))]
-	public async Task ThrowsAny_WithNonAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task ThrowsAny_WithNonAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Action ThrowingMethod = () => {{
-        throw new System.NotImplementedException();
-    }};
-
-    void TestMethod() {{
-        Xunit.Assert.ThrowsAny<System.NotImplementedException>({lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Action ThrowingMethod = () => {{
+			        throw new System.NotImplementedException();
+			    }};
+
+			    void TestMethod() {{
+			        Xunit.Assert.ThrowsAny<System.NotImplementedException>({0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task ThrowsAny_WithAsyncLambda_FindsDiagnostic(string lambda)
+	public async Task ThrowsAny_WithAsyncLambda_Triggers(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    void TestMethod() {{
-        Xunit.Assert.ThrowsAny<System.NotImplementedException>({lambda});
-    }}
-}}";
-		var expected = new[]
-		{
-			DiagnosticResult
-				.CompilerError("CS0619")
-				.WithSpan(8, 9, 8, 65 + lambda.Length)
-				.WithArguments("Xunit.Assert.ThrowsAny<T>(System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAnyAsync<T> (and await the result) when testing async code."),
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 65 + lambda.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments("Assert.ThrowsAny()", Constants.Asserts.ThrowsAnyAsync),
-		};
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    void TestMethod() {{
+			        {{|#0:{{|CS0619:Xunit.Assert.ThrowsAny<System.NotImplementedException>({0})|}}|}};
+			    }}
+			}}
+			""", lambda);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments("Assert.ThrowsAny()", Constants.Asserts.ThrowsAnyAsync);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncLambdas))]
-	public async Task ThrowsAnyAsync_WithAsyncLambda_FindsNoDiagnostics(string lambda)
+	public async Task ThrowsAnyAsync_WithAsyncLambda_DoesNotTrigger(string lambda)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    async void TestMethod() {{
-        await Xunit.Assert.ThrowsAnyAsync<System.NotImplementedException>({lambda});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    async void TestMethod() {{
+			        await Xunit.Assert.ThrowsAnyAsync<System.NotImplementedException>({0});
+			    }}
+			}}
+			""", lambda);
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldUseGenericOverloadCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldUseGenericOverloadCheckTests.cs
index e9e090c3..0872e42c 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldUseGenericOverloadCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AssertThrowsShouldUseGenericOverloadCheckTests.cs
@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Testing;
 using Xunit;
 using Xunit.Analyzers;
@@ -8,142 +7,116 @@
 
 public class AssertThrowsShouldUseGenericOverloadCheckTests
 {
-	public static TheoryData<string> Methods = new()
-	{
+	public static TheoryData<string> Methods =
+	[
 		Constants.Asserts.Throws,
 		Constants.Asserts.ThrowsAsync,
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsWarning_ForThrowsCheck_WithExceptionParameter_OnThrowingMethod(string method)
+	public async Task ForThrowsCheck_WithExceptionParameter_OnThrowingMethod_Triggers(string method)
 	{
-		var source = $@"
-class TestClass {{
-    System.Threading.Tasks.Task ThrowingMethod() {{
-        throw new System.NotImplementedException();
-    }}
-
-    void TestMethod() {{
-        Xunit.Assert.{method}(typeof(System.NotImplementedException), (System.Func<System.Threading.Tasks.Task>)ThrowingMethod);
-    }}
-}}";
-		var expected = new List<DiagnosticResult>
-		{
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 120 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments(method, "System.NotImplementedException"),
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    System.Threading.Tasks.Task ThrowingMethod() {{
+			        throw new System.NotImplementedException();
+			    }}
+
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(typeof(System.NotImplementedException), (System.Func<System.Threading.Tasks.Task>)ThrowingMethod)|}};
+			    }}
+			}}
+			""", method);
+		var expected = new List<DiagnosticResult> {
+			Verify.Diagnostic().WithLocation(0).WithArguments(method, "System.NotImplementedException"),
 		};
-
 		if (method == Constants.Asserts.Throws)
-			expected.Add(
-				DiagnosticResult
-					.CompilerError("CS0619")
-					.WithSpan(8, 9, 8, 120 + method.Length)
-					.WithArguments("Xunit.Assert.Throws(System.Type, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync (and await the result) when testing async code.")
-			);
+			expected.Add(DiagnosticResult.CompilerError("CS0619").WithLocation(0).WithArguments("Xunit.Assert.Throws(System.Type, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync (and await the result) when testing async code."));
 
-		await Verify.VerifyAnalyzer(source, expected.ToArray());
+		await Verify.VerifyAnalyzer(source, [.. expected]);
 	}
 
 	[Theory]
 	[MemberData(nameof(Methods))]
-	public async Task FindsWarning_ForThrowsCheck_WithExceptionParameter_OnThrowingLambda(string method)
+	public async Task ForThrowsCheck_WithExceptionParameter_OnThrowingLambda_Triggers(string method)
 	{
-		var source = $@"
-class TestClass {{
-    void TestMethod() {{
-        Xunit.Assert.{method}(typeof(System.NotImplementedException), () => System.Threading.Tasks.Task.Delay(0));
-    }}
-}}";
-		var expected = new List<DiagnosticResult>
-		{
-			Verify
-				.Diagnostic()
-				.WithSpan(4, 9, 4, 106 + method.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments(method, "System.NotImplementedException")
+		var source = string.Format(/* lang=c#-test */ """
+			class TestClass {{
+			    void TestMethod() {{
+			        {{|#0:Xunit.Assert.{0}(typeof(System.NotImplementedException), () => System.Threading.Tasks.Task.Delay(0))|}};
+			    }}
+			}}
+			""", method);
+		var expected = new List<DiagnosticResult> {
+			Verify.Diagnostic().WithLocation(0).WithArguments(method, "System.NotImplementedException"),
 		};
-
 		if (method == Constants.Asserts.Throws)
-			expected.Add(
-				DiagnosticResult
-					.CompilerError("CS0619")
-					.WithSpan(4, 9, 4, 106 + method.Length)
-					.WithArguments("Xunit.Assert.Throws(System.Type, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync (and await the result) when testing async code.")
-			);
+			expected.Add(DiagnosticResult.CompilerError("CS0619").WithLocation(0).WithArguments("Xunit.Assert.Throws(System.Type, System.Func<System.Threading.Tasks.Task>)", "You must call Assert.ThrowsAsync (and await the result) when testing async code."));
 
 		await Verify.VerifyAnalyzer(source, expected.ToArray());
 	}
 
 	[Fact]
-	public async Task FindsCompilerError_ForThrowsCheck_WithExceptionTypeArgument_OnThrowingMethod()
+	public async Task ForThrowsCheck_WithExceptionTypeArgument_OnThrowingMethod_TriggersCompilerError()
 	{
-		var source = @"
-class TestClass {
-    System.Threading.Tasks.Task ThrowingMethod() {
-        throw new System.NotImplementedException();
-    }
-
-    void TestMethod() {
-        Xunit.Assert.Throws<System.NotImplementedException>((System.Func<System.Threading.Tasks.Task>)ThrowingMethod);
-    }
-}";
-		var expected =
-			Verify
-				.CompilerError("CS0619")
-				.WithSpan(8, 9, 8, 118)
-				.WithMessage($"'Assert.Throws<T>(Func<Task>)' is obsolete: 'You must call Assert.ThrowsAsync<T> (and await the result) when testing async code.'");
-
-		await Verify.VerifyAnalyzer(source, expected);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    System.Threading.Tasks.Task ThrowingMethod() {
+			        throw new System.NotImplementedException();
+			    }
+
+			    void TestMethod() {
+			        {|CS0619:Xunit.Assert.Throws<System.NotImplementedException>((System.Func<System.Threading.Tasks.Task>)ThrowingMethod)|};
+			    }
+			}
+			""";
+
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForThrowsAsyncCheck_WithExceptionTypeArgument_OnThrowingMethod()
+	public async Task ForThrowsAsyncCheck_WithExceptionTypeArgument_OnThrowingMethod_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    System.Threading.Tasks.Task ThrowingMethod() {
-        throw new System.NotImplementedException();
-   }
-
-    async System.Threading.Tasks.Task TestMethod() {
-        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>((System.Func<System.Threading.Tasks.Task>)ThrowingMethod);
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    System.Threading.Tasks.Task ThrowingMethod() {
+			        throw new System.NotImplementedException();
+			   }
+
+			    async System.Threading.Tasks.Task TestMethod() {
+			        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>((System.Func<System.Threading.Tasks.Task>)ThrowingMethod);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task FindsCompilerError_ForThrowsCheck_WithExceptionTypeArgument_OnThrowingLambda()
+	public async Task ForThrowsCheck_WithExceptionTypeArgument_OnThrowingLambda_TriggersCompilerError()
 	{
-		var source = @"
-class TestClass {
-    void TestMethod() {
-        Xunit.Assert.Throws<System.NotImplementedException>(() => System.Threading.Tasks.Task.Delay(0));
-    }
-}";
-		var expected =
-			Verify
-				.CompilerError("CS0619")
-				.WithSpan(4, 9, 4, 104)
-				.WithMessage("'Assert.Throws<T>(Func<Task>)' is obsolete: 'You must call Assert.ThrowsAsync<T> (and await the result) when testing async code.'");
-
-		await Verify.VerifyAnalyzer(source, expected);
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    void TestMethod() {
+			        {|CS0619:Xunit.Assert.Throws<System.NotImplementedException>(() => System.Threading.Tasks.Task.Delay(0))|};
+			    }
+			}
+			""";
+
+		await Verify.VerifyAnalyzer(source);
 	}
 
 	[Fact]
-	public async Task DoesNotFindWarning_ForThrowsAsyncCheck_WithExceptionTypeArgument_OnThrowingLambda()
+	public async Task ForThrowsAsyncCheck_WithExceptionTypeArgument_OnThrowingLambda_DoesNotTrigger()
 	{
-		var source = @"
-class TestClass {
-    async System.Threading.Tasks.Task TestMethod() {
-        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>(() => System.Threading.Tasks.Task.Delay(0));
-    }
-}";
+		var source = /* lang=c#-test */ """
+			class TestClass {
+			    async System.Threading.Tasks.Task TestMethod() {
+			        await Xunit.Assert.ThrowsAsync<System.NotImplementedException>(() => System.Threading.Tasks.Task.Delay(0));
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/AsyncAssertsShouldBeAwaitedTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/AsyncAssertsShouldBeAwaitedTests.cs
index 5d56e55f..45caaff0 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/AsyncAssertsShouldBeAwaitedTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/AsyncAssertsShouldBeAwaitedTests.cs
@@ -1,6 +1,5 @@
 using System.Globalization;
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.AsyncAssertsShouldBeAwaited>;
@@ -8,69 +7,71 @@
 public class AsyncAssertsShouldBeAwaitedTests
 {
 	[Fact]
-	public async Task UnawaitedNonAssertionDoesNotTrigger()
+	public async Task UnawaitedNonAssertion_DoesNotTrigger()
 	{
-		var code = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Task.Delay(1);
-    }
-}";
+		var code = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        Task.Delay(1);
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(code);
 	}
 
-	string codeTemplate = @"
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Threading.Tasks;
-using Xunit;
+	readonly string codeTemplate = /* lang=c#-test */ """
+		using System;
+		using System.Collections.Generic;
+		using System.ComponentModel;
+		using System.Threading.Tasks;
+		using Xunit;
 
-public class TestClass : INotifyPropertyChanged {{
-    public int Property {{ get; set; }}
+		public class TestClass : INotifyPropertyChanged {{
+		    public int Property {{ get; set; }}
 
-    public event PropertyChangedEventHandler? PropertyChanged;
-    public event EventHandler? SimpleEvent;
-    public event EventHandler<int>? SimpleIntEvent;
+		    public event PropertyChangedEventHandler? PropertyChanged;
+		    public event EventHandler? SimpleEvent;
+		    public event EventHandler<int>? SimpleIntEvent;
 
-    [Fact]
-    public async Task TestMethod() {{
-        {0}
-    }}
-}}
+		    [Fact]
+		    public async Task TestMethod() {{
+		        {0}
+		    }}
+		}}
 
-public static class MyTaskExtensions {{
-    public static void ConsumeTask(this Task t) {{ }}
-}}";
+		public static class MyTaskExtensions {{
+		    public static void ConsumeTask(this Task t) {{ }}
+		}}
+		""";
 
 	public static TheoryData<string, string> AsyncAssertions = new()
 	{
-		{ "AllAsync", "Assert.AllAsync(default(IEnumerable<int>), i => Task.FromResult(true))" },
+		/* lang=c#-test */ { "AllAsync", "Assert.AllAsync(default(IEnumerable<int>), i => Task.FromResult(true))" },
 #if NETCOREAPP3_0_OR_GREATER
-		{ "AllAsync", "Assert.AllAsync(default(IAsyncEnumerable<int>), i => Task.FromResult(true))" },
+		/* lang=c#-test */ { "AllAsync", "Assert.AllAsync(default(IAsyncEnumerable<int>), i => Task.FromResult(true))" },
 #endif
-		{ "CollectionAsync", "Assert.CollectionAsync(default(IEnumerable<int>))" },
+		/* lang=c#-test */ { "CollectionAsync", "Assert.CollectionAsync(default(IEnumerable<int>))" },
 #if NETCOREAPP3_0_OR_GREATER
-		{ "CollectionAsync", "Assert.CollectionAsync(default(IAsyncEnumerable<int>))" },
+		/* lang=c#-test */ { "CollectionAsync", "Assert.CollectionAsync(default(IAsyncEnumerable<int>))" },
 #endif
-		{ "PropertyChangedAsync", "Assert.PropertyChangedAsync(this, nameof(Property), async () => throw new DivideByZeroException())" },
-		{ "RaisesAnyAsync", "Assert.RaisesAnyAsync(eh => SimpleEvent += eh, eh => SimpleEvent -= eh, async () => throw new DivideByZeroException())" },
-		{ "RaisesAnyAsync", "Assert.RaisesAnyAsync<int>(eh => SimpleIntEvent += eh, eh => SimpleIntEvent -= eh, async () => throw new DivideByZeroException())" },
-		{ "RaisesAsync", "Assert.RaisesAsync<int>(eh => SimpleIntEvent += eh, eh => SimpleIntEvent -= eh, async () => throw new DivideByZeroException())" },
-		{ "ThrowsAnyAsync", "Assert.ThrowsAnyAsync<Exception>(async () => throw new DivideByZeroException())" },
-		{ "ThrowsAsync", "Assert.ThrowsAsync(typeof(DivideByZeroException), async () => throw new DivideByZeroException())" },
-		{ "ThrowsAsync", "Assert.ThrowsAsync<DivideByZeroException>(async () => throw new DivideByZeroException())" },
-		{ "ThrowsAsync", "Assert.ThrowsAsync<ArgumentException>(\"argName\", async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "PropertyChangedAsync", "Assert.PropertyChangedAsync(this, nameof(Property), async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "RaisesAnyAsync", "Assert.RaisesAnyAsync(eh => SimpleEvent += eh, eh => SimpleEvent -= eh, async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "RaisesAnyAsync", "Assert.RaisesAnyAsync<int>(eh => SimpleIntEvent += eh, eh => SimpleIntEvent -= eh, async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "RaisesAsync", "Assert.RaisesAsync<int>(eh => SimpleIntEvent += eh, eh => SimpleIntEvent -= eh, async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "ThrowsAnyAsync", "Assert.ThrowsAnyAsync<Exception>(async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "ThrowsAsync", "Assert.ThrowsAsync(typeof(DivideByZeroException), async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "ThrowsAsync", "Assert.ThrowsAsync<DivideByZeroException>(async () => throw new DivideByZeroException())" },
+		/* lang=c#-test */ { "ThrowsAsync", "Assert.ThrowsAsync<ArgumentException>(\"argName\", async () => throw new DivideByZeroException())" },
 	};
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AwaitedAssertDoesNotTrigger(
+	public async Task AwaitedAssert_DoesNotTrigger(
 		string _,
 		string assertion)
 	{
@@ -81,7 +82,7 @@ public async Task AwaitedAssertDoesNotTrigger(
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AssertionWithConsumptionNotTrigger(
+	public async Task AssertionWithConsumption_DoesNotTrigger(
 		string _,
 		string assertion)
 	{
@@ -92,7 +93,7 @@ public async Task AssertionWithConsumptionNotTrigger(
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AssertionWithConsumptionViaExtensionNotTrigger(
+	public async Task AssertionWithConsumptionViaExtension_DoesNotTrigger(
 		string _,
 		string assertion)
 	{
@@ -103,7 +104,7 @@ public async Task AssertionWithConsumptionViaExtensionNotTrigger(
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AssertionWithStoredTaskDoesNotTrigger(
+	public async Task AssertionWithStoredTask_DoesNotTrigger(
 		string _,
 		string assertion)
 	{
@@ -114,34 +115,24 @@ public async Task AssertionWithStoredTaskDoesNotTrigger(
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AssertionWithoutAwaitTriggers(
+	public async Task AssertionWithoutAwait_Triggers(
 		string assertionName,
 		string assertion)
 	{
-		var code = string.Format(CultureInfo.InvariantCulture, codeTemplate, $"{assertion};");
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(17, 9, 17, 9 + assertion.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments(assertionName);
+		var code = string.Format(CultureInfo.InvariantCulture, codeTemplate, $"{{|#0:{assertion}|}};");
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(assertionName);
 
 		await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, code, expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
-	public async Task AssertionWithUnawaitedContinuationTriggers(
+	public async Task AssertionWithUnawaitedContinuation_Triggers(
 		string assertionName,
 		string assertion)
 	{
-		var code = string.Format(CultureInfo.InvariantCulture, codeTemplate, $"{assertion}.ContinueWith(t => {{ }});");
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(17, 9, 17, 9 + assertion.Length)
-				.WithSeverity(DiagnosticSeverity.Error)
-				.WithArguments(assertionName);
+		var code = string.Format(CultureInfo.InvariantCulture, codeTemplate, $"{{|#0:{assertion}|}}.ContinueWith(t => {{ }});");
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(assertionName);
 
 		await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, code, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeNegatedTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeNegatedTests.cs
index 6fcddd53..7406b581 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeNegatedTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeNegatedTests.cs
@@ -7,26 +7,23 @@ public class BooleanAssertsShouldNotBeNegatedTests
 	[Theory]
 	[InlineData("False", "True")]
 	[InlineData("True", "False")]
-	public async Task NegatedBooleanAssertionTriggers(
+	public async Task NegatedBooleanAssertion_Triggers(
 		string assertion,
 		string replacement)
 	{
-		var code = $@"
-using Xunit;
+		var code = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        bool condition = true;
+			public class TestClass {{
+			    [Fact]
+			    public void TestMethod() {{
+			        bool condition = true;
 
-        Assert.{assertion}(!condition);
-    }}
-}}";
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(9, 9, 9, 28 + assertion.Length)
-				.WithArguments(assertion, replacement);
+			        {{|#0:Assert.{0}(!condition)|}};
+			    }}
+			}}
+			""", assertion);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(assertion, replacement);
 
 		await Verify.VerifyAnalyzer(code, expected);
 	}
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckTests.cs
index d296b20c..2c498358 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckTests.cs
@@ -1,7 +1,5 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.Testing;
 using Xunit;
 using Xunit.Analyzers;
 using Verify = CSharpVerifier<Xunit.Analyzers.BooleanAssertsShouldNotBeUsedForSimpleEqualityCheck>;
@@ -12,8 +10,8 @@ public class X2024_BooleanAssertionsShouldNotBeUsedForSimpleEqualityCheck
 	{
 		public static MatrixTheoryData<string, string> MethodOperator =
 			new(
-				new[] { Constants.Asserts.True, Constants.Asserts.False },
-				new[] { "==", "!=" }
+				[Constants.Asserts.True, Constants.Asserts.False],
+				["==", "!="]
 			);
 
 		[Theory]
@@ -22,28 +20,29 @@ public async Task ComparingAgainstNonLiteral_DoesNotTrigger(
 			string method,
 			string @operator)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public class TestClass {{
-    public void TestMethod() {{
-        var value1 = 42;
-        var value2 = 2112;
-        var value3 = new {{ innerValue = 2600 }};
+				public class TestClass {{
+				    public void TestMethod() {{
+				        var value1 = 42;
+				        var value2 = 2112;
+				        var value3 = new {{ innerValue = 2600 }};
 
-        Assert.{method}(value1 {@operator} value2);
-        Assert.{method}(value1 {@operator} value3.innerValue);
-    }}
-}}";
+				        Assert.{0}(value1 {1} value2);
+				        Assert.{0}(value1 {1} value3.innerValue);
+				    }}
+				}}
+				""", method, @operator);
 
 			await Verify.VerifyAnalyzer(source);
 		}
 
 		public static MatrixTheoryData<string, string, string> MethodOperatorValue =
 			new(
-				new[] { Constants.Asserts.True, Constants.Asserts.False },
-				new[] { "==", "!=" },
-				new[] { "\"bacon\"", "'5'", "5", "5l", "5.0d", "5.0f", "5.0m", "MyEnum.Bacon" }
+				[Constants.Asserts.True, Constants.Asserts.False],
+				["==", "!="],
+				["\"bacon\"", "'5'", "5", "5l", "5.0d", "5.0f", "5.0m", "MyEnum.Bacon"]
 			);
 
 		[Theory]
@@ -53,19 +52,20 @@ public async Task ComparingAgainstLiteral_WithMessage_DoesNotTrigger(
 			string @operator,
 			string value)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public enum MyEnum {{ None, Bacon, Veggie }}
+				public enum MyEnum {{ None, Bacon, Veggie }}
 
-public class TestClass {{
-    public void TestMethod() {{
-        var value = {value};
+				public class TestClass {{
+				    public void TestMethod() {{
+				        var value = {2};
 
-        Assert.{method}(value {@operator} {value}, ""message"");
-        Assert.{method}({value} {@operator} value, ""message"");
-    }}
-}}";
+				        Assert.{0}(value {1} {2}, "message");
+				        Assert.{0}({2} {1} value, "message");
+				    }}
+				}}
+				""", method, @operator, value);
 
 			await Verify.VerifyAnalyzer(source);
 		}
@@ -77,37 +77,30 @@ public async Task ComparingAgainstLiteral_WithoutMessage_Triggers(
 			string @operator,
 			string value)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public enum MyEnum {{ None, Bacon, Veggie }}
+				public enum MyEnum {{ None, Bacon, Veggie }}
 
-public class TestClass {{
-    public void TestMethod() {{
-        var value = {value};
+				public class TestClass {{
+				    public void TestMethod() {{
+				        var value = {2};
 
-        Assert.{method}(value {@operator} {value});
-        Assert.{method}({value} {@operator} value);
-    }}
-}}";
+				        {{|#0:Assert.{0}(value {1} {2})|}};
+				        {{|#1:Assert.{0}({2} {1} value)|}};
+				    }}
+				}}
+				""", method, @operator, value);
 			var suggestedAssert =
 				(method, @operator) switch
 				{
 					(Constants.Asserts.True, "==") or (Constants.Asserts.False, "!=") => Constants.Asserts.Equal,
 					(_, _) => Constants.Asserts.NotEqual,
 				};
-			DiagnosticResult[] expected =
+			var expected = new[]
 			{
-				Verify
-					.Diagnostic("xUnit2024")
-					.WithSpan(10, 9, 10, 27 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method, suggestedAssert),
-				Verify
-					.Diagnostic("xUnit2024")
-					.WithSpan(11, 9, 11, 27 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method, suggestedAssert),
+				Verify.Diagnostic("xUnit2024").WithLocation(0).WithArguments(method, suggestedAssert),
+				Verify.Diagnostic("xUnit2024").WithLocation(1).WithArguments(method, suggestedAssert),
 			};
 
 			await Verify.VerifyAnalyzer(source, expected);
@@ -115,9 +108,9 @@ public void TestMethod() {{
 
 		public static MatrixTheoryData<string, string, string> MethodOperatorType =
 			new(
-				new[] { Constants.Asserts.True, Constants.Asserts.False },
-				new[] { "==", "!=" },
-				new[] { "string", "int", "object", "MyEnum" }
+				[Constants.Asserts.True, Constants.Asserts.False],
+				["==", "!="],
+				["string", "int", "object", "MyEnum"]
 			);
 
 		[Theory]
@@ -127,19 +120,20 @@ public async Task ComparingAgainstNull_WithMessage_DoesNotTrigger(
 			string @operator,
 			string type)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public enum MyEnum {{ None, Bacon, Veggie }}
+				public enum MyEnum {{ None, Bacon, Veggie }}
 
-public class TestClass {{
-    {type}? field = default;
+				public class TestClass {{
+				    {2}? field = default;
 
-    public void TestMethod() {{
-        Assert.{method}(field {@operator} null, ""Message"");
-        Assert.{method}(null {@operator} field, ""Message"");
-    }}
-}}";
+				    public void TestMethod() {{
+				        Assert.{0}(field {1} null, "Message");
+				        Assert.{0}(null {1} field, "Message");
+				    }}
+				}}
+				""", method, @operator, type);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source);
 		}
@@ -151,37 +145,30 @@ public async Task ComparingAgainstNull_WithoutMessage_Triggers(
 			string @operator,
 			string type)
 		{
-			var source = $@"
-using Xunit;
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
 
-public enum MyEnum {{ None, Bacon, Veggie }}
+				public enum MyEnum {{ None, Bacon, Veggie }}
 
-public class TestClass {{
-    {type}? field = default;
+				public class TestClass {{
+				    {2}? field = default;
 
-    public void TestMethod() {{
-        Assert.{method}(field {@operator} null);
-        Assert.{method}(null {@operator} field);
-    }}
-}}";
+				    public void TestMethod() {{
+				        {{|#0:Assert.{0}(field {1} null)|}};
+				        {{|#1:Assert.{0}(null {1} field)|}};
+				    }}
+				}}
+				""", method, @operator, type);
 			var suggestedAssert =
 				(method, @operator) switch
 				{
 					(Constants.Asserts.True, "==") or (Constants.Asserts.False, "!=") => Constants.Asserts.Null,
 					(_, _) => Constants.Asserts.NotNull,
 				};
-			DiagnosticResult[] expected = new[]
+			var expected = new[]
 			{
-				Verify
-					.Diagnostic("xUnit2024")
-					.WithSpan(10, 9, 10, 31 + method.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method, suggestedAssert),
-				Verify
-					.Diagnostic("xUnit2024")
-					.WithSpan(11, 9, 11, 31 + method.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method, suggestedAssert),
+				Verify.Diagnostic("xUnit2024").WithLocation(0).WithArguments(method, suggestedAssert),
+				Verify.Diagnostic("xUnit2024").WithLocation(1).WithArguments(method, suggestedAssert),
 			};
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp8, source, expected);
@@ -192,9 +179,9 @@ public class X2025_BooleanAssertionCanBeSimplified
 	{
 		public static MatrixTheoryData<string, string, string> MethodOperatorValue =
 			new(
-				new[] { Constants.Asserts.True, Constants.Asserts.False },
-				new[] { "==", "!=" },
-				new[] { "true", "false" }
+				[Constants.Asserts.True, Constants.Asserts.False],
+				["==", "!="],
+				["true", "false"]
 			);
 
 		[Theory]
@@ -204,41 +191,26 @@ public async Task ComparingAgainstBooleanLiteral_Triggers(
 			string @operator,
 			string value)
 		{
-			var source = $@"
-using Xunit;
-
-public class TestClass {{
-    bool field = {value};
-
-    void TestMethod() {{
-        Assert.{method}(field {@operator} {value});
-        Assert.{method}(field {@operator} {value}, ""Message"");
-        Assert.{method}({value} {@operator} field);
-        Assert.{method}({value} {@operator} field, ""Message"");
-    }}
-}}";
-			DiagnosticResult[] expected = new[]
+			var source = string.Format(/* lang=c#-test */ """
+				using Xunit;
+
+				public class TestClass {{
+				    bool field = {2};
+
+				    void TestMethod() {{
+				        {{|#0:Assert.{0}(field {1} {2})|}};
+				        {{|#1:Assert.{0}(field {1} {2}, "Message")|}};
+				        {{|#2:Assert.{0}({2} {1} field)|}};
+				        {{|#3:Assert.{0}({2} {1} field, "Message")|}};
+				    }}
+				}}
+				""", method, @operator, value);
+			var expected = new[]
 			{
-				Verify
-					.Diagnostic("xUnit2025")
-					.WithSpan(8, 9, 8, 27 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method),
-				Verify
-					.Diagnostic("xUnit2025")
-					.WithSpan(9, 9, 9, 38 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method),
-				Verify
-					.Diagnostic("xUnit2025")
-					.WithSpan(10, 9, 10, 27 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method),
-				Verify
-					.Diagnostic("xUnit2025")
-					.WithSpan(11, 9, 11, 38 + method.Length + value.Length)
-					.WithSeverity(DiagnosticSeverity.Info)
-					.WithArguments(method),
+				Verify.Diagnostic("xUnit2025").WithLocation(0).WithArguments(method),
+				Verify.Diagnostic("xUnit2025").WithLocation(1).WithArguments(method),
+				Verify.Diagnostic("xUnit2025").WithLocation(2).WithArguments(method),
+				Verify.Diagnostic("xUnit2025").WithLocation(3).WithArguments(method),
 			};
 
 			await Verify.VerifyAnalyzer(source, expected);
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/DoNotUseAssertEmptyWithProblematicTypesTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/DoNotUseAssertEmptyWithProblematicTypesTests.cs
index 43a66ecd..c11fb2ce 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/DoNotUseAssertEmptyWithProblematicTypesTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/DoNotUseAssertEmptyWithProblematicTypesTests.cs
@@ -1,5 +1,4 @@
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Xunit;
 using Verify = CSharpVerifier<Xunit.Analyzers.DoNotUseAssertEmptyWithProblematicTypes>;
 
@@ -7,27 +6,28 @@ public class DoNotUseAssertEmptyWithProblematicTypesTests
 {
 	public static TheoryData<string, string, string> ProblematicTypes = new()
 	{
-		{ "StringValues.Empty", "StringValues", "it is implicitly cast to a string, not a collection" },
-		{ "new ArraySegment<int>()", "ArraySegment<int>", "its implementation of GetEnumerator() can throw" },
+		/* lang=c#-test */ { "StringValues.Empty", "Microsoft.Extensions.Primitives.StringValues", "it is implicitly cast to a string, not a collection" },
+		/* lang=c#-test */ { "new ArraySegment<int>()", "System.ArraySegment<int>", "its implementation of GetEnumerator() can throw" },
 	};
 
 	[Theory]
-	[InlineData("new int[0]")]
-	[InlineData("new List<int>()")]
-	[InlineData("new Dictionary<string, int>()")]
+	[InlineData(/* lang=c#-test */ "new int[0]")]
+	[InlineData(/* lang=c#-test */ "new List<int>()")]
+	[InlineData(/* lang=c#-test */ "new Dictionary<string, int>()")]
 	public async Task NonProblematicCollection_DoesNotTrigger(string invocation)
 	{
-		var source = @$"
-using System;
-using System.Collections.Generic;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {{
-    public void TestMethod() {{
-        Assert.Empty({invocation});
-        Assert.NotEmpty({invocation});
-    }}
-}}";
+			public class TestClass {{
+			    public void TestMethod() {{
+			        Assert.Empty({0});
+			        Assert.NotEmpty({0});
+			    }}
+			}}
+			""", invocation);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -39,18 +39,19 @@ public async Task ConvertingToCollection_DoesNotTrigger(
 		string _1,
 		string _2)
 	{
-		var source = @$"
-using System;
-using System.Linq;
-using Microsoft.Extensions.Primitives;
-using Xunit;
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using System.Linq;
+			using Microsoft.Extensions.Primitives;
+			using Xunit;
 
-public class TestClass {{
-    public void TestMethod() {{
-        Assert.Empty({invocation}.ToArray());
-        Assert.NotEmpty({invocation}.ToArray());
-    }}
-}}";
+			public class TestClass {{
+			    public void TestMethod() {{
+			        Assert.Empty({0}.ToArray());
+			        Assert.NotEmpty({0}.ToArray());
+			    }}
+			}}
+			""", invocation);
 
 		await Verify.VerifyAnalyzer(source);
 	}
@@ -62,30 +63,22 @@ public async Task UsingProblematicType_Triggers(
 		string typeName,
 		string problem)
 	{
-		var source = @$"
-using System;
-using Microsoft.Extensions.Primitives;
-using Xunit;
-
-public class TestClass {{
-    public void TestMethod() {{
-        Assert.Empty({invocation});
-        Assert.NotEmpty({invocation});
-    }}
-}}";
+		var source = string.Format(/* lang=c#-test */ """
+			using System;
+			using Microsoft.Extensions.Primitives;
+			using Xunit;
 
+			public class TestClass {{
+			    public void TestMethod() {{
+			        {{|#0:Assert.Empty({0})|}};
+			        {{|#1:Assert.NotEmpty({0})|}};
+			    }}
+			}}
+			""", invocation);
 		var expected = new[]
 		{
-			Verify
-				.Diagnostic()
-				.WithSpan(8, 9, 8, 23 + invocation.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Empty", typeName, problem),
-			Verify
-				.Diagnostic()
-				.WithSpan(9, 9, 9, 26 + invocation.Length)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("NotEmpty", typeName, problem),
+			Verify.Diagnostic().WithLocation(0).WithArguments("Empty", typeName, problem),
+			Verify.Diagnostic().WithLocation(1).WithArguments("NotEmpty", typeName, problem),
 		};
 
 		await Verify.VerifyAnalyzer(source, expected);
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/SetEqualityAnalyzerTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/SetEqualityAnalyzerTests.cs
index 23789535..4fc85f85 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/SetEqualityAnalyzerTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/SetEqualityAnalyzerTests.cs
@@ -5,46 +5,47 @@
 
 public class SetEqualityAnalyzerTests
 {
-	const string customSetAndComparer = @"
-using System.Collections;
-using System.Collections.Generic;
-
-public class MySet : ISet<int> {
-    public int Count => throw new System.NotImplementedException();
-    public bool IsReadOnly => throw new System.NotImplementedException();
-
-    public bool Add(int item) => throw new System.NotImplementedException();
-    public void Clear() => throw new System.NotImplementedException();
-    public bool Contains(int item) => throw new System.NotImplementedException();
-    public void CopyTo(int[] array, int arrayIndex) => throw new System.NotImplementedException();
-    public void ExceptWith(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public IEnumerator<int> GetEnumerator() => throw new System.NotImplementedException();
-    public void IntersectWith(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool IsProperSubsetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool IsProperSupersetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool IsSubsetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool IsSupersetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool Overlaps(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public bool Remove(int item) => throw new System.NotImplementedException();
-    public bool SetEquals(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public void SymmetricExceptWith(IEnumerable<int> other) => throw new System.NotImplementedException();
-    public void UnionWith(IEnumerable<int> other) => throw new System.NotImplementedException();
-    void ICollection<int>.Add(int item) => throw new System.NotImplementedException();
-    IEnumerator IEnumerable.GetEnumerator() => throw new System.NotImplementedException();
-}
+	const string customSetAndComparer = /* lang=c#-test */ """
+		using System.Collections;
+		using System.Collections.Generic;
+
+		public class MySet : ISet<int> {
+		    public int Count => throw new System.NotImplementedException();
+		    public bool IsReadOnly => throw new System.NotImplementedException();
+
+		    public bool Add(int item) => throw new System.NotImplementedException();
+		    public void Clear() => throw new System.NotImplementedException();
+		    public bool Contains(int item) => throw new System.NotImplementedException();
+		    public void CopyTo(int[] array, int arrayIndex) => throw new System.NotImplementedException();
+		    public void ExceptWith(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public IEnumerator<int> GetEnumerator() => throw new System.NotImplementedException();
+		    public void IntersectWith(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool IsProperSubsetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool IsProperSupersetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool IsSubsetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool IsSupersetOf(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool Overlaps(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public bool Remove(int item) => throw new System.NotImplementedException();
+		    public bool SetEquals(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public void SymmetricExceptWith(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    public void UnionWith(IEnumerable<int> other) => throw new System.NotImplementedException();
+		    void ICollection<int>.Add(int item) => throw new System.NotImplementedException();
+		    IEnumerator IEnumerable.GetEnumerator() => throw new System.NotImplementedException();
+		}
 
-public class MyComparer : IEqualityComparer<int> {
-    public bool Equals(int x, int y) => throw new System.NotImplementedException();
-    public int GetHashCode(int obj) => throw new System.NotImplementedException();
-}";
+		public class MyComparer : IEqualityComparer<int> {
+		    public bool Equals(int x, int y) => throw new System.NotImplementedException();
+		    public int GetHashCode(int obj) => throw new System.NotImplementedException();
+		}
+		""";
 
 	public class X2026_SetsMustBeComparedWithEqualityComparer
 	{
 		public static MatrixTheoryData<string, string, string> MethodWithCollectionCreationData =>
 			new(
-				new[] { "Equal", "NotEqual" },
-				new[] { "new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()" },
-				new[] { "new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()" }
+				/* lang=c#-test */ ["Equal", "NotEqual"],
+				/* lang=c#-test */ ["new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()"],
+				/* lang=c#-test */ ["new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()"]
 			);
 
 		[Theory]
@@ -54,22 +55,23 @@ public async Task WithCollectionComparer_DoesNotTrigger(
 			string collection1,
 			string collection2)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = {collection1};
-        var collection2 = {collection2};
-
-        Assert.{method}(collection1, collection2, (IEnumerable<int> e1, IEnumerable<int> e2) => true);
-    }}
-}}";
-
-			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, new[] { code, customSetAndComparer });
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Collections.Immutable;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = {1};
+				        var collection2 = {2};
+
+				        Assert.{0}(collection1, collection2, (IEnumerable<int> e1, IEnumerable<int> e2) => true);
+				    }}
+				}}
+				""", method, collection1, collection2);
+
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, [code, customSetAndComparer]);
 		}
 
 		[Theory]
@@ -79,35 +81,33 @@ public async Task WithEqualityComparer_DoesNotTrigger(
 			string collection1,
 			string collection2)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-
-public class TestEqualityComparer : IEqualityComparer<int>
-{{
-    public bool Equals(int x, int y)
-    {{
-        return true;
-    }}
-
-    public int GetHashCode(int obj)
-    {{
-        return 0;
-    }}
-}}
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = {collection1};
-        var collection2 = {collection2};
-
-        Assert.{method}(collection1, collection2, new TestEqualityComparer());
-    }}
-}}";
-
-			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, new[] { code, customSetAndComparer });
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Collections.Immutable;
+
+				public class TestEqualityComparer : IEqualityComparer<int> {{
+				    public bool Equals(int x, int y) {{
+				        return true;
+				    }}
+
+				    public int GetHashCode(int obj) {{
+				        return 0;
+				    }}
+				}}
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = {1};
+				        var collection2 = {2};
+
+				        Assert.{0}(collection1, collection2, new TestEqualityComparer());
+				    }}
+				}}
+				""", method, collection1, collection2);
+
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, [code, customSetAndComparer]);
 		}
 
 		[Theory]
@@ -117,38 +117,34 @@ public async Task WithComparerLambda_Triggers(
 			string collection1,
 			string collection2)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = {collection1};
-        var collection2 = {collection2};
-
-        Assert.{method}(collection1, collection2, (int e1, int e2) => true);
-    }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit2026")
-					.WithSpan(12, 9, 12, 68 + method.Length)
-					.WithArguments(method);
-
-			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, new[] { code, customSetAndComparer }, expected);
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Collections.Immutable;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = {1};
+				        var collection2 = {2};
+
+				        {{|#0:Assert.{0}(collection1, collection2, (int e1, int e2) => true)|}};
+				    }}
+				}}
+				""", method, collection1, collection2);
+			var expected = Verify.Diagnostic("xUnit2026").WithLocation(0).WithArguments(method);
+
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, [code, customSetAndComparer], expected);
 		}
 
 #if ROSLYN_4_4_OR_GREATER  // No C# 10 in Roslyn 3.11, so no local functions
 
 		public static MatrixTheoryData<string, string, string, string> ComparerFunctionData() =>
 			new(
-				new[] { "Equal", "NotEqual" },
-				new[] { "(int e1, int e2) => true", "FuncComparer", "LocalFunc", "funcDelegate" },
-				new[] { "new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()" },
-				new[] { "new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()" }
+				/* lang=c#-test */ ["Equal", "NotEqual"],
+				/* lang=c#-test */ ["(int e1, int e2) => true", "FuncComparer", "LocalFunc", "funcDelegate"],
+				/* lang=c#-test */ ["new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()"],
+				/* lang=c#-test */ ["new HashSet<int>()", "new HashSet<int>().ToImmutableHashSet()", "new MySet()"]
 			);
 
 		[Theory]
@@ -159,54 +155,47 @@ public async Task WithComparerFunction_Triggers(
 			string collection1,
 			string collection2)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Collections.Immutable;
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Collections.Immutable;
 
-public class TestClass {{
-    private bool FuncComparer(int obj1, int obj2)
-    {{
-        return true;
-    }}
+				public class TestClass {{
+				    private bool FuncComparer(int obj1, int obj2) {{
+				        return true;
+				    }}
 
-    private delegate bool FuncDelegate(int obj1, int obj2);
+				    private delegate bool FuncDelegate(int obj1, int obj2);
 
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = {collection1};
-        var collection2 = {collection2};
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = {2};
+				        var collection2 = {3};
 
-        bool LocalFunc(int obj1, int obj2)
-        {{
-            return true;
-        }}
+				        bool LocalFunc(int obj1, int obj2) {{
+				            return true;
+				        }}
 
-        var funcDelegate = FuncComparer;
+				        var funcDelegate = FuncComparer;
 
-        Assert.{method}(collection1, collection2, {comparerFuncSyntax});
-    }}
-}}";
-
-			var expected =
-				Verify
-					.Diagnostic("xUnit2026")
-					.WithSpan(26, 9, 26, 44 + method.Length + comparerFuncSyntax.Length)
-					.WithArguments(method);
+				        {{|#0:Assert.{0}(collection1, collection2, {1})|}};
+				    }}
+				}}
+				""", method, comparerFuncSyntax, collection1, collection2);
+			var expected = Verify.Diagnostic("xUnit2026").WithLocation(0).WithArguments(method);
 
 			await Verify.VerifyAnalyzer(LanguageVersion.CSharp10, new[] { code, customSetAndComparer }, expected);
 		}
 
 #endif
-
 	}
 
 	public class X2027_SetsShouldNotBeComparedToLinearContainers
 	{
 		public static MatrixTheoryData<string, string> MethodAndLinearContainers =>
 			new(
-				new[] { "Equal", "NotEqual" },
-				new[] { "new List<int>()", "new SortedSet<int>()", "new HashSet<int>().OrderBy(x => x)", "new MySet().OrderBy(x => x)" }
+				/* lang=c#-test */ ["Equal", "NotEqual"],
+				/* lang=c#-test */ ["new List<int>()", "new SortedSet<int>()", "new HashSet<int>().OrderBy(x => x)", "new MySet().OrderBy(x => x)"]
 			);
 
 		[Theory]
@@ -215,57 +204,59 @@ public async Task LinearContainers_DoesNotTrigger(
 			string method,
 			string collection)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Linq;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = new List<int>();
-        var collection2 = {collection};
-
-        Assert.{method}(collection1, collection2);
-        Assert.{method}(collection1, collection2, (int e1, int e2) => true);
-        Assert.{method}(collection1, collection2, new MyComparer());
-    }}
-}}";
-
-			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, new[] { code, customSetAndComparer });
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Linq;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = new List<int>();
+				        var collection2 = {1};
+
+				        Assert.{0}(collection1, collection2);
+				        Assert.{0}(collection1, collection2, (int e1, int e2) => true);
+				        Assert.{0}(collection1, collection2, new MyComparer());
+				    }}
+				}}
+				""", method, collection);
+
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, [code, customSetAndComparer]);
 		}
 
 		[Fact]
 		public async Task CastedSet_DoesNotTrigger()
 		{
-			var code = @"
-using Xunit;
-using System.Collections.Generic;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var expected = new HashSet<string> { ""bar"", ""foo"" };
-        var actual = new HashSet<string> { ""foo"", ""bar"" };
-
-         Assert.Equal(expected, actual);
-         Assert.Equal(expected, (ISet<string>)actual);
-         Assert.Equal((ISet<string>)expected, actual);
-         Assert.Equal((ISet<string>)expected, (ISet<string>)actual);
-    }
-}";
+			var code = /* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+
+				public class TestClass {
+				    [Fact]
+				    public void TestMethod() {
+				        var expected = new HashSet<string> { "bar", "foo" };
+				        var actual = new HashSet<string> { "foo", "bar" };
+
+				         Assert.Equal(expected, actual);
+				         Assert.Equal(expected, (ISet<string>)actual);
+				         Assert.Equal((ISet<string>)expected, actual);
+				         Assert.Equal((ISet<string>)expected, (ISet<string>)actual);
+				    }
+				}
+				""";
 
 			await Verify.VerifyAnalyzer(code);
 		}
 
 		public static MatrixTheoryData<string, (string type, string initializer)> MethodAndTypeAndInitializer =>
 			new(
-				new[] { "Equal", "NotEqual" },
-				new[] {
-					("HashSet<int>", "new HashSet<int>()"),
-					("ImmutableHashSet<int>", "new HashSet<int>().ToImmutableHashSet()"),
-					("MySet", "new MySet()")
-				}
+				/* lang=c#-test */ ["Equal", "NotEqual"],
+				/* lang=c#-test */ [
+					("System.Collections.Generic.HashSet<int>", "new HashSet<int>()"),
+									   ("System.Collections.Immutable.ImmutableHashSet<int>", "new HashSet<int>().ToImmutableHashSet()"),
+									   ("MySet", "new MySet()")
+				]
 			);
 
 		[Theory]
@@ -274,57 +265,39 @@ public async Task SetWithLinearContainer_Triggers(
 			string method,
 			(string type, string initializer) collection)
 		{
-			var code = @$"
-using Xunit;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Linq;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection1 = new List<int>();
-        var collection2 = {collection.initializer};
-
-        Assert.{method}(collection1, collection2);
-        Assert.{method}(collection1, collection2, (int e1, int e2) => true);
-        Assert.{method}(collection1, collection2, new MyComparer());
-
-        Assert.{method}(collection2, collection1);
-        Assert.{method}(collection2, collection1, (int e1, int e2) => true);
-        Assert.{method}(collection2, collection1, new MyComparer());
-    }}
-}}";
+			var code = string.Format(/* lang=c#-test */ """
+				using Xunit;
+				using System.Collections.Generic;
+				using System.Collections.Immutable;
+				using System.Linq;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var collection1 = new List<int>();
+				        var collection2 = {1};
+
+				        {{|#0:Assert.{0}(collection1, collection2)|}};
+				        {{|#1:Assert.{0}(collection1, collection2, (int e1, int e2) => true)|}};
+				        {{|#2:Assert.{0}(collection1, collection2, new MyComparer())|}};
+
+				        {{|#3:Assert.{0}(collection2, collection1)|}};
+				        {{|#4:Assert.{0}(collection2, collection1, (int e1, int e2) => true)|}};
+				        {{|#5:Assert.{0}(collection2, collection1, new MyComparer())|}};
+				    }}
+				}}
+				""", method, collection.initializer);
 			var expected = new[]
 			{
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(13, 9, 13, 42 + method.Length)
-					.WithArguments("List<int>", collection.type),
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(14, 9, 14, 68 + method.Length)
-					.WithArguments("List<int>", collection.type),
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(15, 9, 15, 60 + method.Length)
-					.WithArguments("List<int>", collection.type),
-
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(17, 9, 17, 42 + method.Length)
-					.WithArguments(collection.type, "List<int>"),
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(18, 9, 18, 68 + method.Length)
-					.WithArguments(collection.type, "List<int>"),
-				Verify
-					.Diagnostic("xUnit2027")
-					.WithSpan(19, 9, 19, 60 + method.Length)
-					.WithArguments(collection.type, "List<int>"),
+				Verify.Diagnostic("xUnit2027").WithLocation(0).WithArguments("System.Collections.Generic.List<int>", collection.type),
+				Verify.Diagnostic("xUnit2027").WithLocation(1).WithArguments("System.Collections.Generic.List<int>", collection.type),
+				Verify.Diagnostic("xUnit2027").WithLocation(2).WithArguments("System.Collections.Generic.List<int>", collection.type),
+				Verify.Diagnostic("xUnit2027").WithLocation(3).WithArguments(collection.type, "System.Collections.Generic.List<int>"),
+				Verify.Diagnostic("xUnit2027").WithLocation(4).WithArguments(collection.type, "System.Collections.Generic.List<int>"),
+				Verify.Diagnostic("xUnit2027").WithLocation(5).WithArguments(collection.type, "System.Collections.Generic.List<int>"),
 			};
 
-			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, new[] { code, customSetAndComparer }, expected);
+			await Verify.VerifyAnalyzer(LanguageVersion.CSharp7, [code, customSetAndComparer], expected);
 		}
 	}
 }
diff --git a/src/xunit.analyzers.tests/Analyzers/X2000/UseAssertFailInsteadOfBooleanAssertTests.cs b/src/xunit.analyzers.tests/Analyzers/X2000/UseAssertFailInsteadOfBooleanAssertTests.cs
index ff180ab3..94d4f313 100644
--- a/src/xunit.analyzers.tests/Analyzers/X2000/UseAssertFailInsteadOfBooleanAssertTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X2000/UseAssertFailInsteadOfBooleanAssertTests.cs
@@ -8,27 +8,36 @@
 
 public class UseAssertFailInsteadOfBooleanAssertTests
 {
-	const string codeTemplate = @"
-public class TestClass {{
-    [Xunit.Fact]
-    public void TestMethod() {{
-        Xunit.Assert.{0}({1}, ""failure message"");
-    }}
-}}";
+	const string codeTemplate = /* lang=c#-test */ """
+		public class TestClass {{
+		    [Xunit.Fact]
+		    public void TestMethod() {{
+		        {{|#0:Xunit.Assert.{0}({1}, "failure message")|}};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData(Constants.Asserts.True, "false")]
 	[InlineData(Constants.Asserts.False, "true")]
-	public async Task SignalsFor25(
+	public async Task OppositeTestWithMessage_Prev25_DoesNotTrigger(
 		string assertion,
 		string targetValue)
 	{
 		var source = string.Format(codeTemplate, assertion, targetValue);
-		var expected =
-			Verify
-				.Diagnostic()
-				.WithSpan(5, 9, 5, 52)
-				.WithArguments(assertion, targetValue);
+
+		await Verify_Unsupported.VerifyAnalyzer(source);
+	}
+
+	[Theory]
+	[InlineData(Constants.Asserts.True, "false")]
+	[InlineData(Constants.Asserts.False, "true")]
+	public async Task OppositeTestWithMessage_v25_Triggers(
+		string assertion,
+		string targetValue)
+	{
+		var source = string.Format(codeTemplate, assertion, targetValue);
+		var expected = Verify.Diagnostic().WithLocation(0).WithArguments(assertion, targetValue);
 
 		await Verify.VerifyAnalyzer(source, expected);
 	}
@@ -36,7 +45,7 @@ public async Task SignalsFor25(
 	[Theory]
 	[InlineData(Constants.Asserts.True, "true")]
 	[InlineData(Constants.Asserts.False, "false")]
-	public async Task DoesNotSignalForNonFailure(
+	public async Task SameTestWithMessage_DoesNotTrigger(
 		string assertion,
 		string targetValue)
 	{
@@ -46,32 +55,21 @@ public async Task DoesNotSignalForNonFailure(
 	}
 
 	[Fact]
-	public async Task DoesNotSignalForNonConstantInvocation()
+	public async Task NonConstantInvocation_DoesNotTrigger()
 	{
-		var source = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() {
-        var value = (1 != 2);
-        Xunit.Assert.False(value, ""failure message"");
-    }
-}";
+		var source = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() {
+			        var value = (1 != 2);
+			        Xunit.Assert.False(value, "failure message");
+			    }
+			}
+			""";
 
 		await Verify.VerifyAnalyzer(source);
 	}
 
-	[Theory]
-	[InlineData(Constants.Asserts.True, "false")]
-	[InlineData(Constants.Asserts.False, "true")]
-	public async Task DoNotSignalForPre25(
-		string assertion,
-		string targetValue)
-	{
-		var source = string.Format(codeTemplate, assertion, targetValue);
-
-		await Verify_Unsupported.VerifyAnalyzer(source);
-	}
-
 	internal class Analyzer_Pre25 : UseAssertFailInsteadOfBooleanAssert
 	{
 		protected override XunitContext CreateXunitContext(Compilation compilation) =>
diff --git a/src/xunit.analyzers.tests/Analyzers/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.cs b/src/xunit.analyzers.tests/Analyzers/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.cs
index ad8230dd..6fc15052 100644
--- a/src/xunit.analyzers.tests/Analyzers/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.cs
@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Xunit;
@@ -12,45 +10,43 @@ public class CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests
 {
 	public class WithAbstractions
 	{
-		readonly static string Template = @"
-using Xunit.Abstractions;
-
-public class MyClass: {0} {{ }}";
-
-		public static IEnumerable<object[]> Interfaces
-		{
-			get
-			{
-				// Discovery and execution messages
-				yield return new object[] { MemberCount("IMessageSink", 1) };
-				yield return new object[] { MemberCount("IMessageSinkMessage", 0) };
-
-				// Reflection
-				yield return new object[] { MemberCount("IAssemblyInfo", 5) };
-				yield return new object[] { MemberCount("IAttributeInfo", 3) };
-				yield return new object[] { MemberCount("IMethodInfo", 11) };
-				yield return new object[] { MemberCount("IParameterInfo", 2) };
-				yield return new object[] { MemberCount("ITypeInfo", 13) };
-
-				// Test cases
-				yield return new object[] { MemberCount("ITest", 2) };
-				yield return new object[] { MemberCount("ITestAssembly", 4) };
-				yield return new object[] { MemberCount("ITestCase", 9) };
-				yield return new object[] { MemberCount("ITestClass", 4) };
-				yield return new object[] { MemberCount("ITestCollection", 6) };
-				yield return new object[] { MemberCount("ITestMethod", 4) };
-
-				// Test frameworks
-				yield return new object[] { MemberCount("ISourceInformation", 4) };
-				yield return new object[] { MemberCount("ISourceInformationProvider", 2) };
-				yield return new object[] { MemberCount("ITestFramework", 4) };
-				yield return new object[] { MemberCount("ITestFrameworkDiscoverer", 6) };
-				yield return new object[] { MemberCount("ITestFrameworkExecutor", 4) };
-			}
-		}
+		readonly static string Template = /* lang=c#-test */ """
+			using Xunit.Abstractions;
+
+			public class {{|#0:MyClass|}}: {0} {{ }}
+			""";
+
+		public static TheoryData<string> Interfaces =
+		[
+			// Discovery and execution messages
+			MemberCount("IMessageSink", 1),
+			MemberCount("IMessageSinkMessage", 0),
+
+			// Reflection
+			MemberCount("IAssemblyInfo", 5),
+			MemberCount("IAttributeInfo", 3),
+			MemberCount("IMethodInfo", 11),
+			MemberCount("IParameterInfo", 2),
+			MemberCount("ITypeInfo", 13),
+
+			// Test cases
+			MemberCount("ITest", 2),
+			MemberCount("ITestAssembly", 4),
+			MemberCount("ITestCase", 9),
+			MemberCount("ITestClass", 4),
+			MemberCount("ITestCollection", 6),
+			MemberCount("ITestMethod", 4),
+
+			// Test frameworks
+			MemberCount("ISourceInformation", 4),
+			MemberCount("ISourceInformationProvider", 2),
+			MemberCount("ITestFramework", 4),
+			MemberCount("ITestFrameworkDiscoverer", 6),
+			MemberCount("ITestFrameworkExecutor", 4),
+		];
 
 		[Fact]
-		public async Task SuccessCase_NoInterfaces()
+		public async Task NoInterfaces_DoesNotTrigger()
 		{
 			var source = "public class Foo { }";
 
@@ -59,14 +55,10 @@ public async Task SuccessCase_NoInterfaces()
 
 		[Theory]
 		[MemberData(nameof(Interfaces))]
-		public async Task FailureCase_InterfaceWithoutBaseClass(string @interface)
+		public async Task InterfaceWithoutBaseClass_Triggers(string @interface)
 		{
 			var source = string.Format(Template, @interface);
-			var expected =
-				Verify_WithAbstractions
-					.Diagnostic()
-					.WithSpan(4, 14, 4, 21)
-					.WithArguments("MyClass");
+			var expected = Verify_WithAbstractions.Diagnostic().WithLocation(0).WithArguments("MyClass");
 
 			await Verify_WithAbstractions.VerifyAnalyzerV2(source, expected);
 		}
@@ -80,23 +72,15 @@ protected override XunitContext CreateXunitContext(Compilation compilation) =>
 
 	public class WithExecution
 	{
-		readonly static string Template = @"
-using Xunit.Abstractions;
+		readonly static string Template = /* lang=c#-test */ """
+			using Xunit.Abstractions;
 
-public class Foo {{ }}
-public class MyLLMBRO: Xunit.LongLivedMarshalByRefObject {{ }}
-public class MyClass: {0} {{ }}";
+			public class Foo {{ }}
+			public class MyLLMBRO: Xunit.LongLivedMarshalByRefObject {{ }}
+			public class {{|#0:MyClass|}}: {0} {{ }}
+			""";
 
-		public static IEnumerable<object[]> Interfaces
-		{
-			get
-			{
-				foreach (var @interface in WithAbstractions.Interfaces)
-					yield return @interface;
-
-				yield return new object[] { MemberCount("Xunit.Sdk.IXunitTestCase", 13) };
-			}
-		}
+		public static TheoryData<string> Interfaces = new(WithAbstractions.Interfaces) { MemberCount("Xunit.Sdk.IXunitTestCase", 13) };
 
 		public static TheoryData<string, string> InterfacesWithBaseClasses
 		{
@@ -104,7 +88,7 @@ public static TheoryData<string, string> InterfacesWithBaseClasses
 			{
 				var result = new TheoryData<string, string>();
 
-				foreach (var @interface in Interfaces.Select(x => (string)x[0]))
+				foreach (var @interface in Interfaces)
 				{
 					result.Add(@interface, "MyLLMBRO");
 					result.Add(@interface, "Xunit.LongLivedMarshalByRefObject");
@@ -115,15 +99,15 @@ public static TheoryData<string, string> InterfacesWithBaseClasses
 		}
 
 		[Fact]
-		public async Task SuccessCase_NoInterfaces()
+		public async Task NoInterfaces_DoesNotTrigger()
 		{
-			var source = "public class Foo { }";
+			var source = /* lang=c#-test */ "public class Foo { }";
 
 			await Verify_WithExecution.VerifyAnalyzerV2(source);
 		}
 
 		[Fact]
-		public async Task SuccessCase_WithXunitTestCase()
+		public async Task WithXunitTestCase_DoesNotTrigger()
 		{
 			var source = string.Format(Template, "Xunit.Sdk.XunitTestCase");
 
@@ -132,7 +116,7 @@ public async Task SuccessCase_WithXunitTestCase()
 
 		[Theory]
 		[MemberData(nameof(InterfacesWithBaseClasses))]
-		public async Task SuccessCase_CompatibleBaseClass(
+		public async Task CompatibleBaseClass_DoesNotTrigger(
 			string @interface,
 			string baseClass)
 		{
@@ -143,28 +127,20 @@ public async Task SuccessCase_CompatibleBaseClass(
 
 		[Theory]
 		[MemberData(nameof(Interfaces))]
-		public async Task FailureCase_InterfaceWithoutBaseClass(string @interface)
+		public async Task InterfaceWithoutBaseClass_Triggers(string @interface)
 		{
 			var source = string.Format(Template, @interface);
-			var expected =
-				Verify_WithExecution
-					.Diagnostic()
-					.WithSpan(6, 14, 6, 21)
-					.WithArguments("MyClass");
+			var expected = Verify_WithExecution.Diagnostic().WithLocation(0).WithArguments("MyClass");
 
 			await Verify_WithExecution.VerifyAnalyzerV2(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(Interfaces))]
-		public async Task FailureCase_IncompatibleBaseClass(string @interface)
+		public async Task IncompatibleBaseClass_Triggers(string @interface)
 		{
 			var source = string.Format(Template, $"Foo, {@interface}");
-			var expected =
-				Verify_WithExecution
-					.Diagnostic()
-					.WithSpan(6, 14, 6, 21)
-					.WithArguments("MyClass");
+			var expected = Verify_WithExecution.Diagnostic().WithLocation(0).WithArguments("MyClass");
 
 			await Verify_WithExecution.VerifyAnalyzerV2(source, expected);
 		}
@@ -178,14 +154,15 @@ protected override XunitContext CreateXunitContext(Compilation compilation) =>
 
 	public class WithRunnerUtility
 	{
-		readonly static string Template = @"
-using Xunit.Abstractions;
+		readonly static string Template = /* lang=c#-test */ """
+			using Xunit.Abstractions;
 
-public class Foo {{ }}
-public class MyLLMBRO: Xunit.Sdk.LongLivedMarshalByRefObject {{ }}
-public class MyClass: {0} {{ }}";
+			public class Foo {{ }}
+			public class MyLLMBRO: Xunit.Sdk.LongLivedMarshalByRefObject {{ }}
+			public class {{|#0:MyClass|}}: {0} {{ }}
+			""";
 
-		public static IEnumerable<object[]> Interfaces =>
+		public static TheoryData<string> Interfaces =
 			WithAbstractions.Interfaces;
 
 		public static TheoryData<string, string> InterfacesWithBaseClasses
@@ -194,7 +171,7 @@ public static TheoryData<string, string> InterfacesWithBaseClasses
 			{
 				var result = new TheoryData<string, string>();
 
-				foreach (var @interface in Interfaces.Select(x => (string)x[0]))
+				foreach (var @interface in Interfaces)
 				{
 					result.Add(@interface, "MyLLMBRO");
 					result.Add(@interface, "Xunit.Sdk.LongLivedMarshalByRefObject");
@@ -205,16 +182,16 @@ public static TheoryData<string, string> InterfacesWithBaseClasses
 		}
 
 		[Fact]
-		public async Task SuccessCase_NoInterfaces()
+		public async Task NoInterfaces_DoesNotTrigger()
 		{
-			var source = "public class Foo { }";
+			var source = /* lang=c#-test */ "public class Foo { }";
 
 			await Verify_WithRunnerUtility.VerifyAnalyzerV2RunnerUtility(source);
 		}
 
 		[Theory]
 		[MemberData(nameof(InterfacesWithBaseClasses))]
-		public async Task SuccessCase_CompatibleBaseClass(
+		public async Task CompatibleBaseClass_DoesNotTrigger(
 			string @interface,
 			string baseClass)
 		{
@@ -225,28 +202,20 @@ public async Task SuccessCase_CompatibleBaseClass(
 
 		[Theory]
 		[MemberData(nameof(Interfaces))]
-		public async Task FailureCase_InterfaceWithoutBaseClass(string @interface)
+		public async Task InterfaceWithoutBaseClass_Triggers(string @interface)
 		{
 			var source = string.Format(Template, @interface);
-			var expected =
-				Verify_WithRunnerUtility
-					.Diagnostic()
-					.WithSpan(6, 14, 6, 21)
-					.WithArguments("MyClass");
+			var expected = Verify_WithRunnerUtility.Diagnostic().WithLocation(0).WithArguments("MyClass");
 
 			await Verify_WithRunnerUtility.VerifyAnalyzerV2RunnerUtility(source, expected);
 		}
 
 		[Theory]
 		[MemberData(nameof(Interfaces))]
-		public async Task FailureCase_IncompatibleBaseClass(string @interface)
+		public async Task IncompatibleBaseClass_Triggers(string @interface)
 		{
 			var source = string.Format(Template, $"Foo, {@interface}");
-			var expected =
-				Verify_WithRunnerUtility
-					.Diagnostic()
-					.WithSpan(6, 14, 6, 21)
-					.WithArguments("MyClass");
+			var expected = Verify_WithRunnerUtility.Diagnostic().WithLocation(0).WithArguments("MyClass");
 
 			await Verify_WithRunnerUtility.VerifyAnalyzerV2RunnerUtility(source, expected);
 		}
diff --git a/src/xunit.analyzers.tests/Analyzers/X3000/SerializableClassMustHaveParameterlessConstructorTests.cs b/src/xunit.analyzers.tests/Analyzers/X3000/SerializableClassMustHaveParameterlessConstructorTests.cs
index 55e7d67c..5302e42e 100644
--- a/src/xunit.analyzers.tests/Analyzers/X3000/SerializableClassMustHaveParameterlessConstructorTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X3000/SerializableClassMustHaveParameterlessConstructorTests.cs
@@ -7,92 +7,67 @@
 
 public class SerializableClassMustHaveParameterlessConstructorTests
 {
-	static readonly string Template = @"
-using {2};
-
-public interface IMySerializer : IXunitSerializable {{ }}
-public class Foo : {0}
-{{
-    {1}
-    public void Deserialize(IXunitSerializationInfo info) {{ }}
-    public void Serialize(IXunitSerializationInfo info) {{ }}
-}}";
-	public static TheoryData<string> Interfaces = new()
-	{
+	static readonly string Template = /* lang=c#-test */ """
+		using {2};
+
+		public interface IMySerializer : IXunitSerializable {{ }}
+		public class {{|#0:Foo|}} : {0}
+		{{
+		    {1}
+		    public void Deserialize(IXunitSerializationInfo info) {{ }}
+		    public void Serialize(IXunitSerializationInfo info) {{ }}
+		}}
+		""";
+	public static TheoryData<string> Interfaces =
+	[
 		"IXunitSerializable",
 		"IMySerializer"
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(Interfaces))]
-	public async Task ImplicitConstructors_NoDiagnostics(string @interface)
+	public async Task ImplicitConstructors_DoesNotTrigger(string @interface)
 	{
-		var v2Source = string.Format(Template, @interface, "", "Xunit.Abstractions");
-
-		await VerifyV2.VerifyAnalyzerV2(v2Source);
-
-		var v3Source = string.Format(Template, @interface, "", "Xunit.Sdk");
-
-		await VerifyV3.VerifyAnalyzerV3(v3Source);
+		await VerifyV2.VerifyAnalyzerV2(string.Format(Template, @interface, "", "Xunit.Abstractions"));
+		await VerifyV3.VerifyAnalyzerV3(string.Format(Template, @interface, "", "Xunit.Sdk"));
 	}
 
 	[Theory]
 	[MemberData(nameof(Interfaces))]
-	public async Task WrongConstructor_ReturnsError(string @interface)
+	public async Task WrongConstructor_Triggers(string @interface)
 	{
-		var v2Source = string.Format(Template, @interface, "public Foo(int x) { }", "Xunit.Abstractions");
-		var v2Expected =
-			VerifyV2
-				.Diagnostic()
-				.WithSpan(5, 14, 5, 17)
-				.WithArguments("Foo");
+		var v2Source = string.Format(Template, @interface, /* lang=c#-test */ "public Foo(int x) { }", "Xunit.Abstractions");
+		var v2Expected = VerifyV2.Diagnostic().WithLocation(0).WithArguments("Foo");
 
 		await VerifyV2.VerifyAnalyzerV2(v2Source, v2Expected);
 
-		var v3Source = string.Format(Template, @interface, "public Foo(int x) { }", "Xunit.Sdk");
-		var v3Expected =
-			VerifyV3
-				.Diagnostic()
-				.WithSpan(5, 14, 5, 17)
-				.WithArguments("Foo");
+		var v3Source = string.Format(Template, @interface, /* lang=c#-test */ "public Foo(int x) { }", "Xunit.Sdk");
+		var v3Expected = VerifyV3.Diagnostic().WithLocation(0).WithArguments("Foo");
 
 		await VerifyV3.VerifyAnalyzerV3(v3Source, v3Expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Interfaces))]
-	public async Task NonPublicConstructor_ReturnsError(string @interface)
+	public async Task NonPublicConstructor_Triggers(string @interface)
 	{
-		var v2Source = string.Format(Template, @interface, "protected Foo() { }", "Xunit.Abstractions");
-		var v2Expected =
-			VerifyV2
-				.Diagnostic()
-				.WithSpan(5, 14, 5, 17)
-				.WithArguments("Foo");
+		var v2Source = string.Format(Template, @interface, /* lang=c#-test */ "protected Foo() { }", "Xunit.Abstractions");
+		var v2Expected = VerifyV2.Diagnostic().WithLocation(0).WithArguments("Foo");
 
 		await VerifyV2.VerifyAnalyzerV2(v2Source, v2Expected);
 
-		var v3Source = string.Format(Template, @interface, "protected Foo() { }", "Xunit.Sdk");
-		var v3Expected =
-			VerifyV3
-				.Diagnostic()
-				.WithSpan(5, 14, 5, 17)
-				.WithArguments("Foo");
+		var v3Source = string.Format(Template, @interface, /* lang=c#-test */ "protected Foo() { }", "Xunit.Sdk");
+		var v3Expected = VerifyV3.Diagnostic().WithLocation(0).WithArguments("Foo");
 
 		await VerifyV3.VerifyAnalyzerV3(v3Source, v3Expected);
 	}
 
 	[Theory]
 	[MemberData(nameof(Interfaces))]
-	public async Task PublicParameterlessConstructor_NoDiagnostics(string @interface)
+	public async Task PublicParameterlessConstructor_DoesNotTrigger(string @interface)
 	{
-		var v2Source = string.Format(Template, @interface, "public Foo() { }", "Xunit.Abstractions");
-
-		await VerifyV2.VerifyAnalyzerV2(v2Source);
-
-		var v3Source = string.Format(Template, @interface, "public Foo() { }", "Xunit.Sdk");
-
-		await VerifyV3.VerifyAnalyzerV3(v3Source);
+		await VerifyV2.VerifyAnalyzerV2(string.Format(Template, @interface, "public Foo() { }", "Xunit.Abstractions"));
+		await VerifyV3.VerifyAnalyzerV3(string.Format(Template, @interface, "public Foo() { }", "Xunit.Sdk"));
 	}
 
 	public class V2Analyzer : SerializableClassMustHaveParameterlessConstructor
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/ClassDataAttributeMustPointAtValidClassFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/ClassDataAttributeMustPointAtValidClassFixerTests.cs
index f839dd6d..0a9e3fe8 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/ClassDataAttributeMustPointAtValidClassFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/ClassDataAttributeMustPointAtValidClassFixerTests.cs
@@ -8,31 +8,33 @@ public class ClassDataAttributeMustPointAtValidClassFixerTests
 	[Fact]
 	public async Task AddsIEnumerable()
 	{
-		var before = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData {
-}
-
-public class TestClass {
-    [Theory]
-    [{|xUnit1007:ClassData(typeof(TestData))|}]
-    public void TestMethod(int _) { }
-}";
-		var afterV2 = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : {|CS0535:{|CS0535:IEnumerable<object[]>|}|}
-{
-}
-
-public class TestClass {
-    [Theory]
-    [ClassData(typeof(TestData))]
-    public void TestMethod(int _) { }
-}";
+		var before = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData {
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [{|xUnit1007:ClassData(typeof(TestData))|}]
+			    public void TestMethod(int _) { }
+			}
+			""";
+		var afterV2 = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : {|CS0535:{|CS0535:IEnumerable<object[]>|}|}
+			{
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [ClassData(typeof(TestData))]
+			    public void TestMethod(int _) { }
+			}
+			""";
 		var afterV3 = afterV2.Replace("ClassData(typeof(TestData))", "{|xUnit1050:ClassData(typeof(TestData))|}");
 
 		await Verify.VerifyCodeFixV2(before, afterV2, ClassDataAttributeMustPointAtValidClassFixer.Key_FixDataClass);
@@ -42,40 +44,42 @@ public void TestMethod(int _) { }
 	[Fact]
 	public async Task ConvertsParameterlessConstructorToPublic()
 	{
-		var before = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : IEnumerable<object[]> {
-    TestData() { }
-
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}
-
-public class TestClass {
-    [Theory]
-    [{|xUnit1007:ClassData(typeof(TestData))|}]
-    public void TestMethod(int _) { }
-}";
-		var afterV2 = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : IEnumerable<object[]> {
-    public TestData() { }
-
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}
-
-public class TestClass {
-    [Theory]
-    [ClassData(typeof(TestData))]
-    public void TestMethod(int _) { }
-}";
+		var before = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : IEnumerable<object[]> {
+			    TestData() { }
+
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [{|xUnit1007:ClassData(typeof(TestData))|}]
+			    public void TestMethod(int _) { }
+			}
+			""";
+		var afterV2 = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : IEnumerable<object[]> {
+			    public TestData() { }
+
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [ClassData(typeof(TestData))]
+			    public void TestMethod(int _) { }
+			}
+			""";
 		var afterV3 = afterV2.Replace("ClassData(typeof(TestData))", "{|xUnit1050:ClassData(typeof(TestData))|}");
 
 		await Verify.VerifyCodeFixV2(before, afterV2, ClassDataAttributeMustPointAtValidClassFixer.Key_FixDataClass);
@@ -85,44 +89,46 @@ public void TestMethod(int _) { }
 	[Fact]
 	public async Task AddsPublicParameterlessConstructor()
 	{
-		var before = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : IEnumerable<object[]> {
-    TestData(int _) { }
-
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}
-
-public class TestClass {
-    [Theory]
-    [{|xUnit1007:ClassData(typeof(TestData))|}]
-    public void TestMethod(int _) { }
-}";
-		var afterV2 = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : IEnumerable<object[]> {
-    TestData(int _) { }
-
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-
-    public TestData()
-    {
-    }
-}
-
-public class TestClass {
-    [Theory]
-    [ClassData(typeof(TestData))]
-    public void TestMethod(int _) { }
-}";
+		var before = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : IEnumerable<object[]> {
+			    TestData(int _) { }
+
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [{|xUnit1007:ClassData(typeof(TestData))|}]
+			    public void TestMethod(int _) { }
+			}
+			""";
+		var afterV2 = """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : IEnumerable<object[]> {
+			    TestData(int _) { }
+
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+
+			    public TestData()
+			    {
+			    }
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [ClassData(typeof(TestData))]
+			    public void TestMethod(int _) { }
+			}
+			""";
 		var afterV3 = afterV2.Replace("ClassData(typeof(TestData))", "{|xUnit1050:ClassData(typeof(TestData))|}");
 
 		await Verify.VerifyCodeFixV2(before, afterV2, ClassDataAttributeMustPointAtValidClassFixer.Key_FixDataClass);
@@ -132,36 +138,38 @@ public void TestMethod(int _) { }
 	[Fact]
 	public async Task RemovesAbstractModifierFromDataClass()
 	{
-		var before = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public abstract class TestData : IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}
-
-public class TestClass {
-    [Theory]
-    [{|xUnit1007:ClassData(typeof(TestData))|}]
-    public void TestMethod(int _) { }
-}";
-		var afterV2 = @"
-using System.Collections;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestData : IEnumerable<object[]> {
-    public IEnumerator<object[]> GetEnumerator() => null;
-    IEnumerator IEnumerable.GetEnumerator() => null;
-}
-
-public class TestClass {
-    [Theory]
-    [ClassData(typeof(TestData))]
-    public void TestMethod(int _) { }
-}";
+		var before = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public abstract class TestData : IEnumerable<object[]> {
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [{|xUnit1007:ClassData(typeof(TestData))|}]
+			    public void TestMethod(int _) { }
+			}
+			""";
+		var afterV2 = /* lang=c#-test */ """
+			using System.Collections;
+			using System.Collections.Generic;
+			using Xunit;
+
+			public class TestData : IEnumerable<object[]> {
+			    public IEnumerator<object[]> GetEnumerator() => null;
+			    IEnumerator IEnumerable.GetEnumerator() => null;
+			}
+
+			public class TestClass {
+			    [Theory]
+			    [ClassData(typeof(TestData))]
+			    public void TestMethod(int _) { }
+			}
+			""";
 		var afterV3 = afterV2.Replace("ClassData(typeof(TestData))", "{|xUnit1050:ClassData(typeof(TestData))|}");
 
 		await Verify.VerifyCodeFixV2(before, afterV2, ClassDataAttributeMustPointAtValidClassFixer.Key_FixDataClass);
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/CollectionDefinitionClassesMustBePublicFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/CollectionDefinitionClassesMustBePublicFixerTests.cs
index bd5e8335..263161d3 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/CollectionDefinitionClassesMustBePublicFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/CollectionDefinitionClassesMustBePublicFixerTests.cs
@@ -10,13 +10,14 @@ public class CollectionDefinitionClassesMustBePublicFixerTests
 	[InlineData("internal ")]
 	public async Task MakesClassPublic(string modifier)
 	{
-		var before = $@"
-[Xunit.CollectionDefinition(""MyCollection"")]
-{modifier}class [|CollectionDefinitionClass|] {{ }}";
-
-		var after = @"
-[Xunit.CollectionDefinition(""MyCollection"")]
-public class CollectionDefinitionClass { }";
+		var before = string.Format(/* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			{0}class [|CollectionDefinitionClass|] {{ }}
+			""", modifier);
+		var after = /* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			public class CollectionDefinitionClass { }
+			""";
 
 		await Verify.VerifyCodeFix(before, after, CollectionDefinitionClassesMustBePublicFixer.Key_MakeCollectionDefinitionClassPublic);
 	}
@@ -26,17 +27,18 @@ public class CollectionDefinitionClass { }";
 	[InlineData("internal ")]
 	public async Task ForPartialClassDeclarations_MakesSingleDeclarationPublic(string modifier)
 	{
-		var before = $@"
-[Xunit.CollectionDefinition(""MyCollection"")]
-{modifier}partial class [|CollectionDefinitionClass|] {{ }}
-
-partial class CollectionDefinitionClass {{ }}";
-
-		var after = @"
-[Xunit.CollectionDefinition(""MyCollection"")]
-public partial class CollectionDefinitionClass { }
-
-partial class CollectionDefinitionClass { }";
+		var before = string.Format(/* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			{0}partial class [|CollectionDefinitionClass|] {{ }}
+
+			partial class CollectionDefinitionClass {{ }}
+			""", modifier);
+		var after = /* lang=c#-test */ """
+			[Xunit.CollectionDefinition("MyCollection")]
+			public partial class CollectionDefinitionClass { }
+
+			partial class CollectionDefinitionClass { }
+			""";
 
 		await Verify.VerifyCodeFix(before, after, CollectionDefinitionClassesMustBePublicFixer.Key_MakeCollectionDefinitionClassPublic);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/ConvertToFactFixTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/ConvertToFactFixTests.cs
index 651abb0d..95d28f2a 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/ConvertToFactFixTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/ConvertToFactFixTests.cs
@@ -9,21 +9,22 @@ public class ConvertToFactFixTests
 	[Fact]
 	public async Task From_X1003()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    public void [|TestMethod|](int a) { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod(int a) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    public void [|TestMethod|](int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify_X1003.VerifyCodeFix(before, after, ConvertToFactFix.Key_ConvertToFact);
 	}
@@ -31,21 +32,22 @@ public void TestMethod(int a) { }
 	[Fact]
 	public async Task From_X1006()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    public void [|TestMethod|]() { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify_X1006.VerifyCodeFix(before, after, ConvertToFactFix.Key_ConvertToFact);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/ConvertToTheoryFixTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/ConvertToTheoryFixTests.cs
index b48706d8..48182208 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/ConvertToTheoryFixTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/ConvertToTheoryFixTests.cs
@@ -9,21 +9,22 @@ public class ConvertToTheoryFixTests
 	[Fact]
 	public async Task From_X1001()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void [|TestMethod|](int a) { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    public void TestMethod(int a) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void [|TestMethod|](int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify_X1001.VerifyCodeFix(before, after, ConvertToTheoryFix.Key_ConvertToTheory);
 	}
@@ -31,23 +32,24 @@ public void TestMethod(int a) { }
 	[Fact]
 	public async Task From_X1005()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    [InlineData(42)]
-    public void [|TestMethod|]() { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(42)]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    [InlineData(42)]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42)]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify_X1005.VerifyCodeFix(before, after, ConvertToTheoryFix.Key_ConvertToTheory);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/DataAttributeShouldBeUsedOnATheoryFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/DataAttributeShouldBeUsedOnATheoryFixerTests.cs
index d4860acc..e20ee09c 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/DataAttributeShouldBeUsedOnATheoryFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/DataAttributeShouldBeUsedOnATheoryFixerTests.cs
@@ -8,22 +8,23 @@ public class DataAttributeShouldBeUsedOnATheoryFixerTests
 	[Fact]
 	public async Task AddsMissingTheoryAttribute()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [InlineData]
-    public void [|TestMethod|]() { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [InlineData]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, DataAttributeShouldBeUsedOnATheoryFixer.Key_MarkAsTheory);
 	}
@@ -31,20 +32,21 @@ public void TestMethod() { }
 	[Fact]
 	public async Task RemovesDataAttributes()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [InlineData]
-    public void [|TestMethod|]() { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [InlineData]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, DataAttributeShouldBeUsedOnATheoryFixer.Key_RemoveDataAttributes);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseAsyncVoidForTestMethodsFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseAsyncVoidForTestMethodsFixerTests.cs
index f14c5659..607b67a9 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseAsyncVoidForTestMethodsFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseAsyncVoidForTestMethodsFixerTests.cs
@@ -9,33 +9,27 @@ public class DoNotUseAsyncVoidForTestMethodsFixerTests
 	[Fact]
 	public async Task WithoutNamespace_ConvertsToTask()
 	{
-		var beforeV2 = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1048:TestMethod|}() {
-        await System.Threading.Tasks.Task.Yield();
-    }
-}";
-		var beforeV3 = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1049:TestMethod|}() {
-        await System.Threading.Tasks.Task.Yield();
-    }
-}";
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async System.Threading.Tasks.Task TestMethod() {
-        await System.Threading.Tasks.Task.Yield();
-    }
-}";
+		var beforeV2 = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async void {|xUnit1048:TestMethod|}() {
+			        await System.Threading.Tasks.Task.Yield();
+			    }
+			}
+			""";
+		var beforeV3 = beforeV2.Replace("xUnit1048", "xUnit1049");
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async System.Threading.Tasks.Task TestMethod() {
+			        await System.Threading.Tasks.Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFixV2(beforeV2, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToTask);
 		await Verify.VerifyCodeFixV3(beforeV3, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToTask);
@@ -44,36 +38,29 @@ public async System.Threading.Tasks.Task TestMethod() {
 	[Fact]
 	public async Task WithNamespace_ConvertsToTask()
 	{
-		var beforeV2 = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1048:TestMethod|}() {
-        await Task.Yield();
-    }
-}";
-		var beforeV3 = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1049:TestMethod|}() {
-        await Task.Yield();
-    }
-}";
-		var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        await Task.Yield();
-    }
-}";
+		var beforeV2 = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async void {|xUnit1048:TestMethod|}() {
+			        await Task.Yield();
+			    }
+			}
+			""";
+		var beforeV3 = beforeV2.Replace("xUnit1048", "xUnit1049");
+		var after = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async Task TestMethod() {
+			        await Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFixV2(beforeV2, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToTask);
 		await Verify.VerifyCodeFixV3(beforeV3, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToTask);
@@ -82,24 +69,26 @@ public async Task TestMethod() {
 	[Fact]
 	public async Task WithoutNamespace_ConvertsToValueTask()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1049:TestMethod|}() {
-        await System.Threading.Tasks.Task.Yield();
-    }
-}";
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async System.Threading.Tasks.ValueTask TestMethod() {
-        await System.Threading.Tasks.Task.Yield();
-    }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async void {|xUnit1049:TestMethod|}() {
+			        await System.Threading.Tasks.Task.Yield();
+			    }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async System.Threading.Tasks.ValueTask TestMethod() {
+			        await System.Threading.Tasks.Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFixV3(before, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToValueTask);
 	}
@@ -107,26 +96,28 @@ public async System.Threading.Tasks.ValueTask TestMethod() {
 	[Fact]
 	public async Task WithNamespace_ConvertsToValueTask()
 	{
-		var before = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async void {|xUnit1049:TestMethod|}() {
-        await Task.Yield();
-    }
-}";
-		var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async ValueTask TestMethod() {
-        await Task.Yield();
-    }
-}";
+		var before = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async void {|xUnit1049:TestMethod|}() {
+			        await Task.Yield();
+			    }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public async ValueTask TestMethod() {
+			        await Task.Yield();
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFixV3(before, after, DoNotUseAsyncVoidForTestMethodsFixer.Key_ConvertToValueTask);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseConfigureAwaitFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseConfigureAwaitFixerTests.cs
index 13cff60e..4de4addd 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseConfigureAwaitFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/DoNotUseConfigureAwaitFixerTests.cs
@@ -7,13 +7,13 @@ public class DoNotUseConfigureAwaitFixerTests
 {
 	public class ConfigureAwait_Boolean
 	{
-		public static TheoryData<string> InvalidValues = new()
-		{
+		public static TheoryData<string> InvalidValues =
+		[
 			"false",       // Literal false
 			"1 == 2",      // Logical false (we don't compute)
 			"1 == 1",      // Logical true (we don't compute)
 			"booleanVar",  // Reference value (we don't do lookup)
-		};
+		];
 
 		public class RemoveConfigureAwait
 		{
@@ -21,29 +21,30 @@ public class RemoveConfigureAwait
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task Task_Async(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        await Task.Delay(1).[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        await Task.Delay(1);
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        await Task.Delay(1).[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        await Task.Delay(1);
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_RemoveConfigureAwait);
 			}
@@ -52,29 +53,30 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task Task_NonAsync(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var booleanVar = true;
-        Task.Delay(1).[|ConfigureAwait({argumentValue})|].GetAwaiter().GetResult();
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var booleanVar = true;
-        Task.Delay(1).GetAwaiter().GetResult();
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public void TestMethod() {{
+					        var booleanVar = true;
+					        Task.Delay(1).[|ConfigureAwait({0})|].GetAwaiter().GetResult();
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var booleanVar = true;
+					        Task.Delay(1).GetAwaiter().GetResult();
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_RemoveConfigureAwait);
 			}
@@ -83,31 +85,32 @@ public void TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task TaskOfT(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var task = Task.FromResult(42);
-        await task.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var task = Task.FromResult(42);
-        await task;
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var task = Task.FromResult(42);
+					        await task.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var task = Task.FromResult(42);
+					        await task;
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_RemoveConfigureAwait);
 			}
@@ -116,31 +119,32 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task ValueTask(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask);
-        await valueTask.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var valueTask = default(ValueTask);
-        await valueTask;
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask);
+					        await valueTask.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask);
+					        await valueTask;
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_RemoveConfigureAwait);
 			}
@@ -149,31 +153,32 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task ValueTaskOfT(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask<object>);
-        await valueTask.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var valueTask = default(ValueTask<object>);
-        await valueTask;
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask<object>);
+					        await valueTask.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask<object>);
+					        await valueTask;
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_RemoveConfigureAwait);
 			}
@@ -185,29 +190,30 @@ public class ReplaceConfigureAwait
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task Task_Async(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        await Task.Delay(1).[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        await Task.Delay(1).ConfigureAwait(true);
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        await Task.Delay(1).[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        await Task.Delay(1).ConfigureAwait(true);
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 			}
@@ -216,29 +222,30 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task Task_NonAsync(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var booleanVar = true;
-        Task.Delay(1).[|ConfigureAwait({argumentValue})|].GetAwaiter().GetResult();
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var booleanVar = true;
-        Task.Delay(1).ConfigureAwait(true).GetAwaiter().GetResult();
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public void TestMethod() {{
+					        var booleanVar = true;
+					        Task.Delay(1).[|ConfigureAwait({0})|].GetAwaiter().GetResult();
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public void TestMethod() {
+					        var booleanVar = true;
+					        Task.Delay(1).ConfigureAwait(true).GetAwaiter().GetResult();
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 			}
@@ -247,31 +254,32 @@ public void TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task TaskOfT(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var task = Task.FromResult(42);
-        await task.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var task = Task.FromResult(42);
-        await task.ConfigureAwait(true);
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var task = Task.FromResult(42);
+					        await task.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var task = Task.FromResult(42);
+					        await task.ConfigureAwait(true);
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 			}
@@ -280,31 +288,32 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task ValueTask(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask);
-        await valueTask.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var valueTask = default(ValueTask);
-        await valueTask.ConfigureAwait(true);
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask);
+					        await valueTask.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask);
+					        await valueTask.ConfigureAwait(true);
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 			}
@@ -313,31 +322,32 @@ public async Task TestMethod() {
 			[MemberData(nameof(InvalidValues), MemberType = typeof(ConfigureAwait_Boolean))]
 			public async Task ValueTaskOfT(string argumentValue)
 			{
-				var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var booleanVar = true;
-        var valueTask = default(ValueTask<object>);
-        await valueTask.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-				var after = @"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public async Task TestMethod() {
-        var booleanVar = true;
-        var valueTask = default(ValueTask<object>);
-        await valueTask.ConfigureAwait(true);
-    }
-}";
+				var before = string.Format(/* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {{
+					    [Fact]
+					    public async Task TestMethod() {{
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask<object>);
+					        await valueTask.[|ConfigureAwait({0})|];
+					    }}
+					}}
+					""", argumentValue);
+				var after = /* lang=c#-test */ """
+					using System.Threading.Tasks;
+					using Xunit;
+
+					public class TestClass {
+					    [Fact]
+					    public async Task TestMethod() {
+					        var booleanVar = true;
+					        var valueTask = default(ValueTask<object>);
+					        await valueTask.ConfigureAwait(true);
+					    }
+					}
+					""";
 
 				await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 			}
@@ -348,43 +358,45 @@ public async Task TestMethod() {
 
 	public class ConfigureAwait_ConfigureAwaitOptions
 	{
-		public static TheoryData<string> InvalidValues = new()
-		{
+		public static TheoryData<string> InvalidValues =
+		[
 			// Literal values
-			"ConfigureAwaitOptions.None",
-			"ConfigureAwaitOptions.SuppressThrowing",
-			"ConfigureAwaitOptions.ForceYielding | ConfigureAwaitOptions.SuppressThrowing",
+			/* lang=c#-test */ "ConfigureAwaitOptions.None",
+			/* lang=c#-test */ "ConfigureAwaitOptions.SuppressThrowing",
+			/* lang=c#-test */ "ConfigureAwaitOptions.ForceYielding | ConfigureAwaitOptions.SuppressThrowing",
+
 			// Reference values (we don't do lookup)
-			"enumVar",
-		};
+			/* lang=c#-test */ "enumVar",
+		];
 
 		[Theory]
 		[MemberData(nameof(InvalidValues))]
 		public async Task Task_Async(string argumentValue)
 		{
-			var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        await Task.Delay(1).[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-			var after = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        await Task.Delay(1).ConfigureAwait({argumentValue} | ConfigureAwaitOptions.ContinueOnCapturedContext);
-    }}
-}}";
+			var before = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        await Task.Delay(1).[|ConfigureAwait({0})|];
+				    }}
+				}}
+				""", argumentValue);
+			var after = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        await Task.Delay(1).ConfigureAwait({0} | ConfigureAwaitOptions.ContinueOnCapturedContext);
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 		}
@@ -393,29 +405,30 @@ public async Task TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task Task_NonAsync(string argumentValue)
 		{
-			var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        Task.Delay(1).[|ConfigureAwait({argumentValue})|].GetAwaiter().GetResult();
-    }}
-}}";
-
-			var after = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        Task.Delay(1).ConfigureAwait({argumentValue} | ConfigureAwaitOptions.ContinueOnCapturedContext).GetAwaiter().GetResult();
-    }}
-}}";
+			var before = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        Task.Delay(1).[|ConfigureAwait({0})|].GetAwaiter().GetResult();
+				    }}
+				}}
+				""", argumentValue);
+			var after = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public void TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        Task.Delay(1).ConfigureAwait({0} | ConfigureAwaitOptions.ContinueOnCapturedContext).GetAwaiter().GetResult();
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 		}
@@ -424,31 +437,32 @@ public void TestMethod() {{
 		[MemberData(nameof(InvalidValues))]
 		public async Task TaskOfT(string argumentValue)
 		{
-			var before = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        var task = Task.FromResult(42);
-        await task.[|ConfigureAwait({argumentValue})|];
-    }}
-}}";
-
-			var after = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [Fact]
-    public async Task TestMethod() {{
-        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
-        var task = Task.FromResult(42);
-        await task.ConfigureAwait({argumentValue} | ConfigureAwaitOptions.ContinueOnCapturedContext);
-    }}
-}}";
+			var before = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        var task = Task.FromResult(42);
+				        await task.[|ConfigureAwait({0})|];
+				    }}
+				}}
+				""", argumentValue);
+			var after = string.Format(/* lang=c#-test */ """
+				using System.Threading.Tasks;
+				using Xunit;
+
+				public class TestClass {{
+				    [Fact]
+				    public async Task TestMethod() {{
+				        var enumVar = ConfigureAwaitOptions.ContinueOnCapturedContext;
+				        var task = Task.FromResult(42);
+				        await task.ConfigureAwait({0} | ConfigureAwaitOptions.ContinueOnCapturedContext);
+				    }}
+				}}
+				""", argumentValue);
 
 			await Verify.VerifyCodeFix(before, after, DoNotUseConfigureAwaitFixer.Key_ReplaceArgumentValue);
 		}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/FactMethodMustNotHaveParametersFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/FactMethodMustNotHaveParametersFixerTests.cs
index 3f24e755..5a234f3c 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/FactMethodMustNotHaveParametersFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/FactMethodMustNotHaveParametersFixerTests.cs
@@ -8,21 +8,22 @@ public class FactMethodMustNotHaveParametersFixerTests
 	[Fact]
 	public async Task RemovesParameter()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void [|TestMethod|](int x) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Fact]
+			    public void [|TestMethod|](int x) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, FactMethodMustNotHaveParametersFixer.Key_RemoveParameters);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/FactMethodShouldNotHaveTestDataFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/FactMethodShouldNotHaveTestDataFixerTests.cs
index 9eb2dc31..3f81641d 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/FactMethodShouldNotHaveTestDataFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/FactMethodShouldNotHaveTestDataFixerTests.cs
@@ -8,22 +8,23 @@ public class FactMethodShouldNotHaveTestDataFixerTests
 	[Fact]
 	public async Task RemovesDataAttribute()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    [InlineData(1)]
-    public void [|TestMethod|](int x) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Fact]
+			    [InlineData(1)]
+			    public void [|TestMethod|](int x) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod(int x) { }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod(int x) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, FactMethodShouldNotHaveTestDataFixer.Key_RemoveDataAttributes);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_ExtraValueFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_ExtraValueFixerTests.cs
index d210cb78..2202e113 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_ExtraValueFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_ExtraValueFixerTests.cs
@@ -8,23 +8,24 @@ public class InlineDataMustMatchTheoryParameters_ExtraValueFixerTests
 	[Fact]
 	public async Task RemovesUnusedData()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(42, {|xUnit1011:21.12|})]
-    public void TestMethod(int a) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, {|xUnit1011:21.12|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Theory]
-    [InlineData(42)]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42)]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, InlineDataMustMatchTheoryParameters_ExtraValueFixer.Key_RemoveExtraDataValue);
 	}
@@ -36,23 +37,24 @@ public async Task AddsParameterWithCorrectType(
 		string value,
 		string valueType)
 	{
-		var before = $@"
-using Xunit;
+		var before = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [InlineData(42, {{|xUnit1011:{value}|}})]
-    public void TestMethod(int a) {{ }}
-}}";
+			public class TestClass {{
+			    [Theory]
+			    [InlineData(42, {{|xUnit1011:{0}|}})]
+			    public void TestMethod(int a) {{ }}
+			}}
+			""", value);
+		var after = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-		var after = $@"
-using Xunit;
-
-public class TestClass {{
-    [Theory]
-    [InlineData(42, {value})]
-    public void TestMethod(int a, {valueType} p) {{ }}
-}}";
+			public class TestClass {{
+			    [Theory]
+			    [InlineData(42, {0})]
+			    public void TestMethod(int a, {1} p) {{ }}
+			}}
+			""", value, valueType);
 
 		await Verify.VerifyCodeFix(before, after, InlineDataMustMatchTheoryParameters_ExtraValueFixer.Key_AddTheoryParameter);
 	}
@@ -60,23 +62,24 @@ public void TestMethod(int a, {valueType} p) {{ }}
 	[Fact]
 	public async Task AddsParameterWithNonConflictingName()
 	{
-		var before = $@"
-using Xunit;
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [InlineData(42, {{|xUnit1011:21.12|}})]
-    public void TestMethod(int p) {{ }}
-}}";
-
-		var after = $@"
-using Xunit;
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, {|xUnit1011:21.12|})]
+			    public void TestMethod(int p) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [InlineData(42, 21.12)]
-    public void TestMethod(int p, double p_2) {{ }}
-}}";
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, 21.12)]
+			    public void TestMethod(int p, double p_2) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, InlineDataMustMatchTheoryParameters_ExtraValueFixer.Key_AddTheoryParameter);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
index 7525c4f3..7b3620cf 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
@@ -9,23 +9,24 @@ public class InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompati
 	[Fact]
 	public async Task MakesParameterNullable()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(42, {|xUnit1012:null|})]
-    public void TestMethod(int a, int b) { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(42, null)]
-    public void TestMethod(int a, int? b) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, {|xUnit1012:null|})]
+			    public void TestMethod(int a, int b) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, null)]
+			    public void TestMethod(int a, int? b) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixer.Key_MakeParameterNullable);
 	}
@@ -33,27 +34,28 @@ public void TestMethod(int a, int? b) { }
 	[Fact]
 	public async Task MakesReferenceParameterNullable()
 	{
-		var before = @"
-using Xunit;
-
-#nullable enable
-public class TestClass {
-    [Theory]
-    [InlineData(42, {|xUnit1012:null|})]
-    public void TestMethod(int a, object b) { }
-#nullable restore
-}";
-
-		var after = @"
-using Xunit;
-
-#nullable enable
-public class TestClass {
-    [Theory]
-    [InlineData(42, null)]
-    public void TestMethod(int a, object? b) { }
-#nullable restore
-}";
+		var before = /* lang=c#-test */ """
+			#nullable enable
+
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, {|xUnit1012:null|})]
+			    public void TestMethod(int a, object b) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			#nullable enable
+
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(42, null)]
+			    public void TestMethod(int a, object? b) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(LanguageVersion.CSharp8, before, after, InlineDataMustMatchTheoryParameters_NullShouldNotBeUsedForIncompatibleParameterFixer.Key_MakeParameterNullable);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_TooFewValuesFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_TooFewValuesFixerTests.cs
index 328bed28..a4b731c7 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_TooFewValuesFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataMustMatchTheoryParameters_TooFewValuesFixerTests.cs
@@ -18,27 +18,28 @@ public async Task MakesParameterNullable(
 		string valueType,
 		string defaultValue)
 	{
-		var before = $@"
-using Xunit;
-
-public enum Color {{ Red, Green, Blue }}
+		var before = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Theory]
-    [{{|xUnit1009:InlineData|}}]
-    public void TestMethod({valueType} p) {{ }}
-}}";
+			public enum Color {{ Red, Green, Blue }}
 
-		var after = $@"
-using Xunit;
+			public class TestClass {{
+			    [Theory]
+			    [{{|xUnit1009:InlineData|}}]
+			    public void TestMethod({0} p) {{ }}
+			}}
+			""", valueType);
+		var after = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public enum Color {{ Red, Green, Blue }}
+			public enum Color {{ Red, Green, Blue }}
 
-public class TestClass {{
-    [Theory]
-    [InlineData({defaultValue})]
-    public void TestMethod({valueType} p) {{ }}
-}}";
+			public class TestClass {{
+			    [Theory]
+			    [InlineData({1})]
+			    public void TestMethod({0} p) {{ }}
+			}}
+			""", valueType, defaultValue);
 
 		await Verify.VerifyCodeFix(before, after, InlineDataMustMatchTheoryParameters_TooFewValuesFixer.Key_AddDefaultValues);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataShouldBeUniqueWithinTheoryFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataShouldBeUniqueWithinTheoryFixerTests.cs
index 7adbd740..66abda92 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/InlineDataShouldBeUniqueWithinTheoryFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/InlineDataShouldBeUniqueWithinTheoryFixerTests.cs
@@ -8,24 +8,25 @@ public class InlineDataShouldBeUniqueWithinTheoryFixerTests
 	[Fact]
 	public async Task RemovesDuplicateData()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    [[|InlineData(1)|]]
-    public void TestMethod(int x) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    [[|InlineData(1)|]]
+			    public void TestMethod(int x) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    public void TestMethod(int x) { }
-}";
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    public void TestMethod(int x) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, InlineDataShouldBeUniqueWithinTheoryFixer.Key_RemoveDuplicateInlineData);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/LocalFunctionsCannotBeTestFunctionsFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/LocalFunctionsCannotBeTestFunctionsFixerTests.cs
index 63637751..9de0dd50 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/LocalFunctionsCannotBeTestFunctionsFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/LocalFunctionsCannotBeTestFunctionsFixerTests.cs
@@ -11,25 +11,27 @@ public class LocalFunctionsCannotBeTestFunctionsFixerTests
 	[InlineData("Theory")]
 	public async Task LocalFunctionsCannotHaveTestAttributes(string attribute)
 	{
-		var before = $@"
-using Xunit;
+		var before = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    public void Method() {{
-        [[|{attribute}|]]
-        void LocalFunction() {{
-        }}
-    }}
-}}";
-		var after = @"
-using Xunit;
+			public class TestClass {{
+			    public void Method() {{
+			        [[|{0}|]]
+			        void LocalFunction() {{
+			        }}
+			    }}
+			}}
+			""", attribute);
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    public void Method() {
-        void LocalFunction() {
-        }
-    }
-}";
+			public class TestClass {
+			    public void Method() {
+			        void LocalFunction() {
+			        }
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(LanguageVersion.CSharp9, before, after, LocalFunctionsCannotBeTestFunctionsFixer.Key_RemoveAttribute);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ExtraValueFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ExtraValueFixerTests.cs
index 5fbdc172..617c1ceb 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ExtraValueFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ExtraValueFixerTests.cs
@@ -8,27 +8,28 @@ public class MemberDataShouldReferenceValidMember_ExtraValueFixerTests
 	[Fact]
 	public async Task RemovesUnusedData()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, {|xUnit1036:21.12|})]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
 
-		var after = @"
-using Xunit;
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {|xUnit1036:21.12|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(TestData), 42)]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(TestData), 42)]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_ExtraValueFixer.Key_RemoveExtraDataValue);
 	}
@@ -40,27 +41,28 @@ public async Task AddsParameterWithCorrectType(
 		string value,
 		string valueType)
 	{
-		var before = $@"
-using Xunit;
+		var before = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
+			public class TestClass {{
+			    public static TheoryData<int> TestData(int n) => new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, {{|xUnit1036:{value}|}})]
-    public void TestMethod(int a) {{ }}
-}}";
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {{|xUnit1036:{0}|}})]
+			    public void TestMethod(int a) {{ }}
+			}}
+			""", value);
+		var after = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-		var after = $@"
-using Xunit;
-
-public class TestClass {{
-    public static TheoryData<int> TestData(int n, {valueType} p) => new TheoryData<int>();
+			public class TestClass {{
+			    public static TheoryData<int> TestData(int n, {1} p) => new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, {value})]
-    public void TestMethod(int a) {{ }}
-}}";
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {0})]
+			    public void TestMethod(int a) {{ }}
+			}}
+			""", value, valueType);
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_ExtraValueFixer.Key_AddMethodParameter);
 	}
@@ -68,27 +70,28 @@ public void TestMethod(int a) {{ }}
 	[Fact]
 	public async Task AddsParameterWithNonConflictingName()
 	{
-		var before = $@"
-using Xunit;
-
-public class TestClass {{
-    public static TheoryData<int> TestData(int p) => new TheoryData<int>();
-
-    [Theory]
-    [MemberData(nameof(TestData), 42, {{|xUnit1036:21.12|}})]
-    public void TestMethod(int n) {{ }}
-}}";
-
-		var after = $@"
-using Xunit;
-
-public class TestClass {{
-    public static TheoryData<int> TestData(int p, double p_2) => new TheoryData<int>();
-
-    [Theory]
-    [MemberData(nameof(TestData), 42, 21.12)]
-    public void TestMethod(int n) {{ }}
-}}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    public static TheoryData<int> TestData(int p) => new TheoryData<int>();
+
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {|xUnit1036:21.12|})]
+			    public void TestMethod(int n) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    public static TheoryData<int> TestData(int p, double p_2) => new TheoryData<int>();
+
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, 21.12)]
+			    public void TestMethod(int n) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_ExtraValueFixer.Key_AddMethodParameter);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NameOfFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NameOfFixerTests.cs
index 604c6b3f..08bb389b 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NameOfFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NameOfFixerTests.cs
@@ -8,31 +8,32 @@ public class MemberDataShouldReferenceValidMember_NameOfFixerTests
 	[Fact]
 	public async Task ConvertStringToNameOf()
 	{
-		var before = @"
-using System;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-    public static TheoryData<int> DataSource;
+		var before = /* lang=c#-test */ """
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-    [Theory]
-    [MemberData({|xUnit1014:""DataSource""|})]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static TheoryData<int> DataSource;
 
-		var after = @"
-using System;
-using System.Collections.Generic;
-using Xunit;
+			    [Theory]
+			    [MemberData({|xUnit1014:"DataSource"|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> DataSource;
+			public class TestClass {
+			    public static TheoryData<int> DataSource;
 
-    [Theory]
-    [MemberData(nameof(DataSource))]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(DataSource))]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_NameOfFixer.Key_UseNameof);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
index c4afdda4..e66d5e68 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixerTests.cs
@@ -9,27 +9,28 @@ public class MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompat
 	[Fact]
 	public async Task MakesParameterNullable()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    public static TheoryData<int> TestData(int n, int k) => new TheoryData<int>();
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, {|xUnit1034:null|})]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n, int k) => new TheoryData<int>();
 
-		var after = @"
-using Xunit;
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {|xUnit1034:null|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> TestData(int n, int? k) => new TheoryData<int>();
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n, int? k) => new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, null)]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, null)]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixer.Key_MakeParameterNullable);
 	}
@@ -37,31 +38,32 @@ public void TestMethod(int a) { }
 	[Fact]
 	public async Task MakesReferenceParameterNullable()
 	{
-		var before = @"
-#nullable enable
+		var before = /* lang=c#-test */ """
+			#nullable enable
 
-using Xunit;
-
-public class TestClass {
-    public static TheoryData<int> TestData(int n, string k) => new TheoryData<int> { n };
+			using Xunit;
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, {|xUnit1034:null|})]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n, string k) => new TheoryData<int> { n };
 
-		var after = @"
-#nullable enable
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, {|xUnit1034:null|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			#nullable enable
 
-using Xunit;
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> TestData(int n, string? k) => new TheoryData<int> { n };
+			public class TestClass {
+			    public static TheoryData<int> TestData(int n, string? k) => new TheoryData<int> { n };
 
-    [Theory]
-    [MemberData(nameof(TestData), 42, null)]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(TestData), 42, null)]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(LanguageVersion.CSharp8, before, after, MemberDataShouldReferenceValidMember_NullShouldNotBeUsedForIncompatibleParameterFixer.Key_MakeParameterNullable);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ParamsForNonMethodFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ParamsForNonMethodFixerTests.cs
index 04a60889..3f137ad8 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ParamsForNonMethodFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ParamsForNonMethodFixerTests.cs
@@ -8,33 +8,34 @@ public class MemberDataShouldReferenceValidMember_ParamsForNonMethodFixerTests
 	[Fact]
 	public async Task RemovesParametersFromNonMethodMemberData()
 	{
-		var before = @"
-using System;
-using System.Collections.Generic;
-using Xunit;
+		var before = /* lang=c#-test */ """
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass
-{
-    public static TheoryData<int> DataSource = new TheoryData<int>();
+			public class TestClass
+			{
+			    public static TheoryData<int> DataSource = new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(DataSource), {|xUnit1021:""abc"", 123|})]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(DataSource), {|xUnit1021:"abc", 123|})]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System;
+			using System.Collections.Generic;
+			using Xunit;
 
-		var after = @"
-using System;
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass
-{
-    public static TheoryData<int> DataSource = new TheoryData<int>();
+			public class TestClass
+			{
+			    public static TheoryData<int> DataSource = new TheoryData<int>();
 
-    [Theory]
-    [MemberData(nameof(DataSource))]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(DataSource))]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_ParamsForNonMethodFixer.Key_RemoveArgumentsFromMemberData);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ReturnTypeFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ReturnTypeFixerTests.cs
index 383b9ca4..244e6ddd 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ReturnTypeFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_ReturnTypeFixerTests.cs
@@ -8,29 +8,30 @@ public class MemberDataShouldReferenceValidMember_ReturnTypeFixerTests
 	[Fact]
 	public async Task ChangesReturnType_ObjectArray()
 	{
-		var before = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-    public static IEnumerable<object> Data => null;
+		var before = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-    [Theory]
-    [{|xUnit1019:MemberData(nameof(Data))|}]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static IEnumerable<object> Data => null;
 
-		var after = @"
-using System.Collections.Generic;
-using Xunit;
+			    [Theory]
+			    [{|xUnit1019:MemberData(nameof(Data))|}]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {
-    public static IEnumerable<object[]> Data => null;
+			public class TestClass {
+			    public static IEnumerable<object[]> Data => null;
 
-    [Theory]
-    [{|xUnit1042:MemberData(nameof(Data))|}]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [{|xUnit1042:MemberData(nameof(Data))|}]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_ReturnTypeFixer.Key_ChangeMemberReturnType_ObjectArray);
 	}
@@ -38,29 +39,30 @@ public void TestMethod(int a) { }
 	[Fact]
 	public async Task ChangesReturnType_TheoryDataRow()
 	{
-		var before = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-    public static IEnumerable<object> Data => null;
+		var before = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-    [Theory]
-    [{|xUnit1019:MemberData(nameof(Data))|}]
-    public void TestMethod(int a) { }
-}";
+			public class TestClass {
+			    public static IEnumerable<object> Data => null;
 
-		var after = @"
-using System.Collections.Generic;
-using Xunit;
+			    [Theory]
+			    [{|xUnit1019:MemberData(nameof(Data))|}]
+			    public void TestMethod(int a) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {
-    public static IEnumerable<ITheoryDataRow> Data => null;
+			public class TestClass {
+			    public static IEnumerable<ITheoryDataRow> Data => null;
 
-    [Theory]
-    [{|xUnit1042:MemberData(nameof(Data))|}]
-    public void TestMethod(int a) { }
-}";
+			    [Theory]
+			    [{|xUnit1042:MemberData(nameof(Data))|}]
+			    public void TestMethod(int a) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFixV3(before, after, MemberDataShouldReferenceValidMember_ReturnTypeFixer.Key_ChangeMemberReturnType_ITheoryDataRow);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_StaticFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_StaticFixerTests.cs
index 1a2c5ca5..f85ab4d3 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_StaticFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_StaticFixerTests.cs
@@ -8,29 +8,30 @@ public class MemberDataShouldReferenceValidMember_StaticFixerTests
 	[Fact]
 	public async Task MarksDataMemberAsStatic()
 	{
-		var before = @"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {
-    public TheoryData<int> TestData => null;
+		var before = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-    [Theory]
-    [{|xUnit1017:MemberData(nameof(TestData))|}]
-    public void TestMethod(int x) { }
-}";
+			public class TestClass {
+			    public TheoryData<int> TestData => null;
 
-		var after = @"
-using System.Collections.Generic;
-using Xunit;
+			    [Theory]
+			    [{|xUnit1017:MemberData(nameof(TestData))|}]
+			    public void TestMethod(int x) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> TestData => null;
+			public class TestClass {
+			    public static TheoryData<int> TestData => null;
 
-    [Theory]
-    [MemberData(nameof(TestData))]
-    public void TestMethod(int x) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(TestData))]
+			    public void TestMethod(int x) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_StaticFixer.Key_MakeMemberStatic);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_VisibilityFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_VisibilityFixerTests.cs
index 43d5916e..e183daff 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_VisibilityFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/MemberDataShouldReferenceValidMember_VisibilityFixerTests.cs
@@ -11,29 +11,30 @@ public class MemberDataShouldReferenceValidMember_VisibilityFixerTests
 	[InlineData("internal ")]
 	public async Task SetsPublicModifier(string badModifier)
 	{
-		var before = $@"
-using System.Collections.Generic;
-using Xunit;
-
-public class TestClass {{
-    {badModifier}static TheoryData<int> TestData => null;
+		var before = string.Format(/* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-    [Theory]
-    [{{|xUnit1016:MemberData(nameof(TestData))|}}]
-    public void TestMethod(int x) {{ }}
-}}";
+			public class TestClass {{
+			    {0}static TheoryData<int> TestData => null;
 
-		var after = @"
-using System.Collections.Generic;
-using Xunit;
+			    [Theory]
+			    [{{|xUnit1016:MemberData(nameof(TestData))|}}]
+			    public void TestMethod(int x) {{ }}
+			}}
+			""", badModifier);
+		var after = /* lang=c#-test */ """
+			using System.Collections.Generic;
+			using Xunit;
 
-public class TestClass {
-    public static TheoryData<int> TestData => null;
+			public class TestClass {
+			    public static TheoryData<int> TestData => null;
 
-    [Theory]
-    [MemberData(nameof(TestData))]
-    public void TestMethod(int x) { }
-}";
+			    [Theory]
+			    [MemberData(nameof(TestData))]
+			    public void TestMethod(int x) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, MemberDataShouldReferenceValidMember_VisibilityFixer.Key_MakeMemberPublic);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/PublicMethodShouldBeMarkedAsTestFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/PublicMethodShouldBeMarkedAsTestFixerTests.cs
index 4cac3900..97ba1c88 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/PublicMethodShouldBeMarkedAsTestFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/PublicMethodShouldBeMarkedAsTestFixerTests.cs
@@ -5,38 +5,41 @@
 
 public class PublicMethodShouldBeMarkedAsTestFixerTests
 {
-	const string beforeNoParams = @"
-using Xunit;
+	const string beforeNoParams = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
+		public class TestClass {
+		    [Fact]
+		    public void TestMethod() { }
 
-    public void [|TestMethod2|]() { }
-}";
-	const string beforeWithParams = @"
-using Xunit;
+		    public void [|TestMethod2|]() { }
+		}
+		""";
+	const string beforeWithParams = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
+		public class TestClass {
+		    [Fact]
+		    public void TestMethod() { }
 
-    public void [|TestMethod2|](int _) { }
-}";
+		    public void [|TestMethod2|](int _) { }
+		}
+		""";
 
 	[Fact]
 	public async Task AddsFactToPublicMethodWithoutParameters()
 	{
-		var after = @"
-using Xunit;
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
 
-    [Fact]
-    public void TestMethod2() { }
-}";
+			    [Fact]
+			    public void TestMethod2() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(beforeNoParams, after, PublicMethodShouldBeMarkedAsTestFixer.Key_ConvertToFact);
 	}
@@ -44,16 +47,17 @@ public void TestMethod2() { }
 	[Fact]
 	public async Task AddsFactToPublicMethodWithParameters()
 	{
-		var after = @"
-using Xunit;
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
 
-    [Theory]
-    public void TestMethod2(int _) { }
-}";
+			    [Theory]
+			    public void TestMethod2(int _) { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(beforeWithParams, after, PublicMethodShouldBeMarkedAsTestFixer.Key_ConvertToTheory);
 	}
@@ -63,7 +67,7 @@ public void TestMethod2(int _) { }
 	[InlineData(beforeWithParams)]
 	public async Task MarksMethodAsInternal(string before)
 	{
-		var after = before.Replace("public void [|TestMethod2|]", "internal void TestMethod2");
+		var after = before.Replace(/* lang=c#-test */ "public void [|TestMethod2|]", /* lang=c#-test */ "internal void TestMethod2");
 
 		await Verify.VerifyCodeFix(before, after, PublicMethodShouldBeMarkedAsTestFixer.Key_MakeMethodInternal);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/RemoveMethodParameterFixTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/RemoveMethodParameterFixTests.cs
index 5598d8de..35b5b8ae 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/RemoveMethodParameterFixTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/RemoveMethodParameterFixTests.cs
@@ -12,23 +12,24 @@ public class RemoveMethodParameterFixTests
 	[Fact]
 	public async Task X1022_RemoveParamsArray()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1, 2, 3)]
-    public void TestMethod([|params int[] values|]) { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1, 2, 3)]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1, 2, 3)]
+			    public void TestMethod([|params int[] values|]) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1, 2, 3)]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify_X1022.VerifyCodeFix(before, after, RemoveMethodParameterFix.Key_RemoveParameter);
 	}
@@ -36,23 +37,24 @@ public void TestMethod() { }
 	[Fact]
 	public async Task X1026_RemovesUnusedParameter()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    public void TestMethod(int [|arg|]) { }
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    public void TestMethod(int [|arg|]) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify_X1026.VerifyCodeFix(before, after, RemoveMethodParameterFix.Key_RemoveParameter);
 	}
@@ -60,48 +62,32 @@ public void TestMethod() { }
 	[Fact]
 	public async Task X1026_DoesNotCrashWhenParameterDeclarationIsMissing()
 	{
-		var before = @"
-using Xunit;
+		var before = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+				[Theory]
+				[InlineData(1, 1)]
+				public void Test1(int x, {|CS1001:{|CS1031:{|xUnit1026:|})|}|}
+				{
+					var x1 = x;
+				}
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+				[Theory]
+				[InlineData(1, 1)]
+				public void Test1(int x, {|CS1001:{|CS1031:{|xUnit1026:|})|}|}
+				{
+					var x1 = x;
+				}
+			}
+			""";
 
-public class TestClass {
-	[Theory]
-	[InlineData(1, 1)]
-	public void Test1(int x, )
-	{
-		var x1 = x;
-	}
-}";
-
-		var after = @"
-using Xunit;
-
-public class TestClass {
-	[Theory]
-	[InlineData(1, 1)]
-	public void Test1(int x, )
-	{
-		var x1 = x;
-	}
-}";
-
-		var expected = new[]
-		{
-			Verify_X1026
-				.Diagnostic()
-				.WithSpan(7, 27, 7, 27)
-				.WithSeverity(DiagnosticSeverity.Warning)
-				.WithArguments("Test1", "TestClass", ""),
-			Verify_X1026
-				.CompilerError("CS1001")
-				.WithSpan(7, 27, 7, 28)
-				.WithMessage("Identifier expected"),
-			Verify_X1026
-				.CompilerError("CS1031")
-				.WithSpan(7, 27, 7, 28)
-				.WithMessage("Type expected"),
-		};
-
-		await Verify_X1026.VerifyCodeFix(before, after, RemoveMethodParameterFix.Key_RemoveParameter, expected);
+		await Verify_X1026.VerifyCodeFix(before, after, RemoveMethodParameterFix.Key_RemoveParameter);
 	}
 
 	internal class Analyzer_X1022 : TheoryMethodCannotHaveParamsArray
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TestClassCannotBeNestedInGenericClassFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TestClassCannotBeNestedInGenericClassFixerTests.cs
index e2eb4e48..6c317b45 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TestClassCannotBeNestedInGenericClassFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TestClassCannotBeNestedInGenericClassFixerTests.cs
@@ -8,25 +8,27 @@ public class TestClassCannotBeNestedInGenericClassFixerTests
 	[Fact]
 	public async Task MovesTestClassOutOfGenericParent()
 	{
-		const string before = @"
-public abstract class OpenGenericType<T>
-{
-    public class [|NestedTestClass|]
-    {
-        [Xunit.Fact]
-        public void TestMethod() { }
-    }
-}";
-		const string after = @"
-public abstract class OpenGenericType<T>
-{
-}
+		const string before = /* lang=c#-test */ """
+			public abstract class OpenGenericType<T>
+			{
+			    public class [|NestedTestClass|]
+			    {
+			        [Xunit.Fact]
+			        public void TestMethod() { }
+			    }
+			}
+			""";
+		const string after = /* lang=c#-test */ """
+			public abstract class OpenGenericType<T>
+			{
+			}
 
-public class NestedTestClass
-{
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			public class NestedTestClass
+			{
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestClassCannotBeNestedInGenericClassFixer.Key_ExtractTestClass);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TestClassMustBePublicFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TestClassMustBePublicFixerTests.cs
index 6fa3ed18..c553ad4a 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TestClassMustBePublicFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TestClassMustBePublicFixerTests.cs
@@ -7,20 +7,21 @@ public class TestClassMustBePublicFixerTests
 {
 	[Theory]
 	[InlineData("")]
-	[InlineData("internal")]
+	[InlineData("internal ")]
 	public async Task MakesClassPublic(string nonPublicAccessModifier)
 	{
-		var before = $@"
-{nonPublicAccessModifier} class [|TestClass|] {{
-    [Xunit.Fact]
-    public void TestMethod() {{ }}
-}}";
-
-		var after = @"
-public class TestClass {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var before = string.Format(/* lang=c#-test */ """
+			{0}class [|TestClass|] {{
+			    [Xunit.Fact]
+			    public void TestMethod() {{ }}
+			}}
+			""", nonPublicAccessModifier);
+		var after = /* lang=c#-test */ """
+			public class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestClassMustBePublicFixer.Key_MakeTestClassPublic);
 	}
@@ -28,27 +29,28 @@ public void TestMethod() { }
 	[Fact]
 	public async Task ForPartialClassDeclarations_MakesSingleDeclarationPublic()
 	{
-		var before = @"
-partial class [|TestClass|] {
-    [Xunit.Fact]
-    public void TestMethod1() {}
-}
-
-partial class TestClass {
-    [Xunit.Fact]
-    public void TestMethod2() {}
-}";
-
-		var after = @"
-public partial class TestClass {
-    [Xunit.Fact]
-    public void TestMethod1() {}
-}
-
-partial class TestClass {
-    [Xunit.Fact]
-    public void TestMethod2() {}
-}";
+		var before = /* lang=c#-test */ """
+			partial class [|TestClass|] {
+			    [Xunit.Fact]
+			    public void TestMethod1() {}
+			}
+
+			partial class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod2() {}
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			public partial class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod1() {}
+			}
+
+			partial class TestClass {
+			    [Xunit.Fact]
+			    public void TestMethod2() {}
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestClassMustBePublicFixer.Key_MakeTestClassPublic);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TestClassShouldHaveTFixtureArgumentFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TestClassShouldHaveTFixtureArgumentFixerTests.cs
index 2f1aef7c..3e8ee87a 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TestClassShouldHaveTFixtureArgumentFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TestClassShouldHaveTFixtureArgumentFixerTests.cs
@@ -8,28 +8,29 @@ public class TestClassShouldHaveTFixtureArgumentFixerTests
 	[Fact]
 	public async Task ForClassWithoutField_GenerateFieldAndConstructor()
 	{
-		var before = @"
-public class FixtureData { }
+		var before = /* lang=c#-test */ """
+			public class FixtureData { }
 
-public class [|TestClass|]: Xunit.IClassFixture<FixtureData> {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			public class [|TestClass|]: Xunit.IClassFixture<FixtureData> {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			public class FixtureData { }
 
-		var after = @"
-public class FixtureData { }
+			public class TestClass: Xunit.IClassFixture<FixtureData> {
+			    private readonly FixtureData _fixtureData;
 
-public class [|TestClass|]: Xunit.IClassFixture<FixtureData> {
-    private readonly FixtureData _fixtureData;
+			    public TestClass(FixtureData fixtureData)
+			    {
+			        _fixtureData = fixtureData;
+			    }
 
-    public TestClass(FixtureData fixtureData)
-    {
-        _fixtureData = fixtureData;
-    }
-
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestClassShouldHaveTFixtureArgumentFixer.Key_GenerateConstructor);
 	}
@@ -37,28 +38,29 @@ public void TestMethod() { }
 	[Fact]
 	public async Task ForGenericTFixture_GenerateFieldAndConstructor()
 	{
-		var before = @"
-public class FixtureData<T> { }
-
-public class [|TestClass|]: Xunit.IClassFixture<FixtureData<object>> {
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			public class FixtureData<T> { }
 
-		var after = @"
-public class FixtureData<T> { }
+			public class [|TestClass|]: Xunit.IClassFixture<FixtureData<object>> {
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			public class FixtureData<T> { }
 
-public class [|TestClass|]: Xunit.IClassFixture<FixtureData<object>> {
-    private readonly FixtureData<object> _fixtureData;
+			public class TestClass: Xunit.IClassFixture<FixtureData<object>> {
+			    private readonly FixtureData<object> _fixtureData;
 
-    public TestClass(FixtureData<object> fixtureData)
-    {
-        _fixtureData = fixtureData;
-    }
+			    public TestClass(FixtureData<object> fixtureData)
+			    {
+			        _fixtureData = fixtureData;
+			    }
 
-    [Xunit.Fact]
-    public void TestMethod() { }
-}";
+			    [Xunit.Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestClassShouldHaveTFixtureArgumentFixer.Key_GenerateConstructor);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TestMethodMustNotHaveMultipleFactAttributesFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TestMethodMustNotHaveMultipleFactAttributesFixerTests.cs
index b470f2c7..f8c97373 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TestMethodMustNotHaveMultipleFactAttributesFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TestMethodMustNotHaveMultipleFactAttributesFixerTests.cs
@@ -8,26 +8,27 @@ public class TestMethodMustNotHaveMultipleFactAttributesFixerTests
 	[Fact]
 	public async Task RemovesSecondAttribute()
 	{
-		var before = $@"
-using Xunit;
-
-public class FactDerivedAttribute : FactAttribute {{ }}
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [Fact]
-    [{{|CS0579:Fact|}}]
-    public void [|TestMethod|]() {{ }}
-}}";
+			public class FactDerivedAttribute : FactAttribute { }
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Fact]
+			    [{|CS0579:Fact|}]
+			    public void [|TestMethod|]() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class FactDerivedAttribute : FactAttribute { }
+			public class FactDerivedAttribute : FactAttribute { }
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestMethodMustNotHaveMultipleFactAttributesFixer.Key_KeepAttribute("Fact"));
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TestMethodShouldNotBeSkippedFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TestMethodShouldNotBeSkippedFixerTests.cs
index a8a48925..5e52ed53 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TestMethodShouldNotBeSkippedFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TestMethodShouldNotBeSkippedFixerTests.cs
@@ -8,21 +8,22 @@ public class TestMethodShouldNotBeSkippedFixerTests
 	[Fact]
 	public async Task RemovesSkipProperty()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact([|Skip = ""Don't run this""|])]
-    public void TestMethod() { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Fact([|Skip = "Don't run this"|])]
+			    public void TestMethod() { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() { }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() { }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, TestMethodShouldNotBeSkippedFixer.Key_RemoveSkipArgument);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X1000/TheoryMethodCannotHaveDefaultParameterFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X1000/TheoryMethodCannotHaveDefaultParameterFixerTests.cs
index 74b3ecb5..4423d6c5 100644
--- a/src/xunit.analyzers.tests/Fixes/X1000/TheoryMethodCannotHaveDefaultParameterFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X1000/TheoryMethodCannotHaveDefaultParameterFixerTests.cs
@@ -11,23 +11,24 @@ public class TheoryMethodCannotHaveDefaultParameterFixerTests
 	[Fact]
 	public async Task RemovesDefaultParameterValue()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    public void TestMethod(int _ [|= 0|]) { }
-}";
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-		var after = @"
-using Xunit;
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    public void TestMethod(int _ [|= 0|]) { }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Theory]
-    [InlineData(1)]
-    public void TestMethod(int _) { }
-}";
+			public class TestClass {
+			    [Theory]
+			    [InlineData(1)]
+			    public void TestMethod(int _) { }
+			}
+			""";
 
 		await Verify_v2_Pre220.VerifyCodeFix(before, after, TheoryMethodCannotHaveDefaultParameterFixer.Key_RemoveParameterDefault);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertCollectionContainsShouldNotUseBoolCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertCollectionContainsShouldNotUseBoolCheckFixerTests.cs
index 97f05408..8983b1d0 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertCollectionContainsShouldNotUseBoolCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertCollectionContainsShouldNotUseBoolCheckFixerTests.cs
@@ -5,33 +5,34 @@
 
 public class AssertCollectionContainsShouldNotUseBoolCheckFixerTests
 {
-	const string template = @"
-using System;
-using System.Linq;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System;
+		using System.Linq;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var items = new[] {{ ""a"", ""b"", ""c"" }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var items = new[] {{ "a", "b", "c" }};
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData(
-		@"[|Assert.True(items.Contains(""b""))|]",
-		@"Assert.Contains(""b"", items)")]
+		/* lang=c#-test */ @"[|Assert.True(items.Contains(""b""))|]",
+		/* lang=c#-test */ @"Assert.Contains(""b"", items)")]
 	[InlineData(
-		@"[|Assert.True(items.Contains(""b"", StringComparer.Ordinal))|]",
-		@"Assert.Contains(""b"", items, StringComparer.Ordinal)")]
+		/* lang=c#-test */ @"[|Assert.True(items.Contains(""b"", StringComparer.Ordinal))|]",
+		/* lang=c#-test */ @"Assert.Contains(""b"", items, StringComparer.Ordinal)")]
 	[InlineData(
-		@"[|Assert.False(items.Contains(""b""))|]",
-		@"Assert.DoesNotContain(""b"", items)")]
+		/* lang=c#-test */ @"[|Assert.False(items.Contains(""b""))|]",
+		/* lang=c#-test */ @"Assert.DoesNotContain(""b"", items)")]
 	[InlineData(
-		@"[|Assert.False(items.Contains(""b"", StringComparer.Ordinal))|]",
-		@"Assert.DoesNotContain(""b"", items, StringComparer.Ordinal)")]
+		/* lang=c#-test */ @"[|Assert.False(items.Contains(""b"", StringComparer.Ordinal))|]",
+		/* lang=c#-test */ @"Assert.DoesNotContain(""b"", items, StringComparer.Ordinal)")]
 	public async Task ReplacesBooleanAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyCollectionCheckShouldNotBeUsedFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyCollectionCheckShouldNotBeUsedFixerTests.cs
index a54f01ba..8cc9e076 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyCollectionCheckShouldNotBeUsedFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyCollectionCheckShouldNotBeUsedFixerTests.cs
@@ -5,32 +5,34 @@
 
 public class AssertEmptyCollectionCheckShouldNotBeUsedFixerTests
 {
-	readonly string before = @"
-using Xunit;
+	const string before = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var collection = new[] { 1, 2, 3 };
+		public class TestClass {
+		    [Fact]
+		    public void TestMethod() {
+		        var collection = new[] { 1, 2, 3 };
 
-        [|Assert.Collection(collection)|];
-    }
-}";
+		        [|Assert.Collection(collection)|];
+		    }
+		}
+		""";
 
 	[Fact]
 	public async Task UseEmptyCheck()
 	{
-		var after = @"
-using Xunit;
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var collection = new[] { 1, 2, 3 };
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        var collection = new[] { 1, 2, 3 };
 
-        Assert.Empty(collection);
-    }
-}";
+			        Assert.Empty(collection);
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, AssertEmptyCollectionCheckShouldNotBeUsedFixer.Key_UseAssertEmpty);
 	}
@@ -38,17 +40,18 @@ public void TestMethod() {
 	[Fact]
 	public async Task AddElementInspector()
 	{
-		var after = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var collection = new[] { 1, 2, 3 };
-
-        Assert.Collection(collection, x => { });
-    }
-}";
+		var after = /* lang=c#-test */ """
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        var collection = new[] { 1, 2, 3 };
+
+			        Assert.Collection(collection, x => { });
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, AssertEmptyCollectionCheckShouldNotBeUsedFixer.Key_AddElementInspector);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckFixerTests.cs
index 3e317a83..efe54c55 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckFixerTests.cs
@@ -5,25 +5,32 @@
 
 public class AssertEmptyShouldNotBeUsedForCollectionDoesNotContainCheckFixerTests
 {
-	const string template = @"
-using System.Linq;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System.Linq;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var list = new[] {{ -1, 0, 1, 2 }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var list = new[] {{ -1, 0, 1, 2 }};
 
-        {0};
-    }}
+		        {0};
+		    }}
 
-	public bool IsEven(int num) => num % 2 == 0;
-}}";
+			public bool IsEven(int num) => num % 2 == 0;
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.Empty(list.Where(f => f > 0))|]", "Assert.DoesNotContain(list, f => f > 0)")]
-	[InlineData("[|Assert.Empty(list.Where(n => n == 1))|]", "Assert.DoesNotContain(list, n => n == 1)")]
-	[InlineData("[|Assert.Empty(list.Where(IsEven))|]", "Assert.DoesNotContain(list, IsEven)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Empty(list.Where(f => f > 0))|]",
+		/* lang=c#-test */ "Assert.DoesNotContain(list, f => f > 0)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Empty(list.Where(n => n == 1))|]",
+		/* lang=c#-test */ "Assert.DoesNotContain(list, n => n == 1)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Empty(list.Where(IsEven))|]",
+		/* lang=c#-test */ "Assert.DoesNotContain(list, IsEven)")]
 	public async Task FixerReplacesAssertEmptyWithAssertDoesNotContain(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckFixerTests.cs
index 066191c3..b69ff610 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckFixerTests.cs
@@ -5,26 +5,27 @@
 
 public class AssertEnumerableAnyCheckShouldNotBeUsedForCollectionContainsCheckFixerTests
 {
-	const string template = @"
-using System.Linq;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System.Linq;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var collection = new[] {{ 1, 2, 3 }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var collection = new[] {{ 1, 2, 3 }};
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData(
-		"[|Assert.True(collection.Any(x => x == 2))|]",
-		"Assert.Contains(collection, x => x == 2)")]
+		/* lang=c#-test */ "[|Assert.True(collection.Any(x => x == 2))|]",
+		/* lang=c#-test */ "Assert.Contains(collection, x => x == 2)")]
 	[InlineData(
-		"[|Assert.False(collection.Any(x => x == 2))|]",
-		"Assert.DoesNotContain(collection, x => x == 2)")]
+		/* lang=c#-test */ "[|Assert.False(collection.Any(x => x == 2))|]",
+		/* lang=c#-test */ "Assert.DoesNotContain(collection, x => x == 2)")]
 	public async Task ReplacesAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualGenericShouldNotBeUsedForStringValueFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualGenericShouldNotBeUsedForStringValueFixerTests.cs
index ac93006b..826ed162 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualGenericShouldNotBeUsedForStringValueFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualGenericShouldNotBeUsedForStringValueFixerTests.cs
@@ -6,17 +6,18 @@
 
 public class AssertEqualGenericShouldNotBeUsedForStringValueFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        string result = ""foo"";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        string result = "foo";
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData(Constants.Asserts.Equal)]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualLiteralValueShouldBeFirstFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualLiteralValueShouldBeFirstFixerTests.cs
index 95f16a18..4c676191 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualLiteralValueShouldBeFirstFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualLiteralValueShouldBeFirstFixerTests.cs
@@ -6,24 +6,38 @@
 
 public class AssertEqualLiteralValueShouldBeFirstFixerTests
 {
-	static readonly string Template = @"
-using System.Collections.Generic;
+	const string Template = /* lang=c#-test */ """
+		using System.Collections.Generic;
 
-public class TestClass {{
-    [Xunit.Fact]
-    public void TestMethod() {{
-        var i = 0;
-        [|Xunit.{0}|];
-    }}
-}}";
+		public class TestClass {{
+		    [Xunit.Fact]
+		    public void TestMethod() {{
+		        var i = 0;
+		        [|Xunit.{0}|];
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("Assert.Equal(i, 0)", "Assert.Equal(0, i)")]
-	[InlineData("Assert.Equal(actual: 0, expected: i)", "Assert.Equal(actual: i, expected: 0)")]
-	[InlineData("Assert.Equal(expected: i, actual: 0)", "Assert.Equal(expected: 0, actual: i)")]
-	[InlineData("Assert.Equal(comparer: default(IEqualityComparer<int>), actual: 0, expected: i)", "Assert.Equal(comparer: default(IEqualityComparer<int>), actual: i, expected: 0)")]
-	[InlineData("Assert.Equal(comparer: (x, y) => true, actual: 0, expected: i)", "Assert.Equal(comparer: (x, y) => true, actual: i, expected: 0)")]
-	[InlineData("Assert.Equal(expected: i, 0)", "Assert.Equal(expected: 0, i)", LanguageVersion.CSharp7_2)]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(i, 0)",
+		/* lang=c#-test */ "Assert.Equal(0, i)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(actual: 0, expected: i)",
+		/* lang=c#-test */ "Assert.Equal(actual: i, expected: 0)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(expected: i, actual: 0)",
+		/* lang=c#-test */ "Assert.Equal(expected: 0, actual: i)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(comparer: default(IEqualityComparer<int>), actual: 0, expected: i)",
+		/* lang=c#-test */ "Assert.Equal(comparer: default(IEqualityComparer<int>), actual: i, expected: 0)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(comparer: (x, y) => true, actual: 0, expected: i)",
+		/* lang=c#-test */ "Assert.Equal(comparer: (x, y) => true, actual: i, expected: 0)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(expected: i, 0)",
+		/* lang=c#-test */ "Assert.Equal(expected: 0, i)",
+		LanguageVersion.CSharp7_2)]
 	public async Task SwapArguments(
 		string beforeAssert,
 		string afterAssert,
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualPrecisionShouldBeInRangeFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualPrecisionShouldBeInRangeFixerTests.cs
index 034f11aa..be8df4a8 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualPrecisionShouldBeInRangeFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualPrecisionShouldBeInRangeFixerTests.cs
@@ -5,23 +5,32 @@
 
 public class AssertEqualPrecisionShouldBeInRangeFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        {0};
-    }}
-}}";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	// double = [0..15]
-	[InlineData("Assert.Equal(10.1d, 10.2d, [|-1|])", "Assert.Equal(10.1d, 10.2d, 0)")]
-	[InlineData("Assert.Equal(10.1d, 10.2d, [|16|])", "Assert.Equal(10.1d, 10.2d, 15)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(10.1d, 10.2d, [|-1|])",
+		/* lang=c#-test */ "Assert.Equal(10.1d, 10.2d, 0)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(10.1d, 10.2d, [|16|])",
+		/* lang=c#-test */ "Assert.Equal(10.1d, 10.2d, 15)")]
 	// decimal = [0..28]
-	[InlineData("Assert.Equal(10.1m, 10.2m, [|-1|])", "Assert.Equal(10.1m, 10.2m, 0)")]
-	[InlineData("Assert.Equal(10.1m, 10.2m, [|29|])", "Assert.Equal(10.1m, 10.2m, 28)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(10.1m, 10.2m, [|-1|])",
+		/* lang=c#-test */ "Assert.Equal(10.1m, 10.2m, 0)")]
+	[InlineData(
+		/* lang=c#-test */ "Assert.Equal(10.1m, 10.2m, [|29|])",
+		/* lang=c#-test */ "Assert.Equal(10.1m, 10.2m, 28)")]
 	public async Task ChangesPrecisionToZero(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckFixerTests.cs
index 9fe17243..746b1b39 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForBoolLiteralCheckFixerTests.cs
@@ -5,27 +5,44 @@
 
 public class AssertEqualShouldNotBeUsedForBoolLiteralCheckFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var actual = true;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var actual = true;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.Equal(false, actual)|]", "Assert.False(actual)")]
-	[InlineData("[|Assert.Equal(true, actual)|]", "Assert.True(actual)")]
-	[InlineData("[|Assert.StrictEqual(false, actual)|]", "Assert.False(actual)")]
-	[InlineData("[|Assert.StrictEqual(true, actual)|]", "Assert.True(actual)")]
-	[InlineData("[|Assert.NotEqual(false, actual)|]", "Assert.True(actual)")]
-	[InlineData("[|Assert.NotEqual(true, actual)|]", "Assert.False(actual)")]
-	[InlineData("[|Assert.NotStrictEqual(false, actual)|]", "Assert.True(actual)")]
-	[InlineData("[|Assert.NotStrictEqual(true, actual)|]", "Assert.False(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Equal(false, actual)|]",
+		/* lang=c#-test */ "Assert.False(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Equal(true, actual)|]",
+		/* lang=c#-test */ "Assert.True(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.StrictEqual(false, actual)|]",
+		/* lang=c#-test */ "Assert.False(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.StrictEqual(true, actual)|]",
+		/* lang=c#-test */ "Assert.True(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotEqual(false, actual)|]",
+		/* lang=c#-test */ "Assert.True(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotEqual(true, actual)|]",
+		/* lang=c#-test */ "Assert.False(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotStrictEqual(false, actual)|]",
+		/* lang=c#-test */ "Assert.True(actual)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotStrictEqual(true, actual)|]",
+		/* lang=c#-test */ "Assert.False(actual)")]
 	public async Task ConvertsToBooleanAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckFixerTests.cs
index ba493b1c..f3efd68f 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForCollectionSizeCheckFixerTests.cs
@@ -5,23 +5,30 @@
 
 public class AssertEqualShouldNotBeUsedForCollectionSizeCheckFixerTests
 {
-	const string template = @"
-using System.Linq;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System.Linq;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = new[] {{ 1, 2, 3 }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = new[] {{ 1, 2, 3 }};
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.Equal(1, data.Count())|]", "Assert.Single(data)")]
-	[InlineData("[|Assert.Equal(0, data.Count())|]", "Assert.Empty(data)")]
-	[InlineData("[|Assert.NotEqual(0, data.Count())|]", "Assert.NotEmpty(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Equal(1, data.Count())|]",
+		/* lang=c#-test */ "Assert.Single(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Equal(0, data.Count())|]",
+		/* lang=c#-test */ "Assert.Empty(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotEqual(0, data.Count())|]",
+		/* lang=c#-test */ "Assert.NotEmpty(data)")]
 	public async Task ReplacesCollectionCountWithAppropriateAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForNullCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForNullCheckFixerTests.cs
index f73c5d6e..8621a9a5 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForNullCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualShouldNotBeUsedForNullCheckFixerTests.cs
@@ -5,23 +5,32 @@
 
 public class AssertEqualShouldNotBeUsedForNullCheckFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        int? data = 1;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        int? data = 1;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.Equal(null, data)|]", "Assert.Null(data)")]
-	[InlineData("[|Assert.StrictEqual(null, data)|]", "Assert.Null(data)")]
-	[InlineData("[|Assert.NotEqual(null, data)|]", "Assert.NotNull(data)")]
-	[InlineData("[|Assert.NotStrictEqual(null, data)|]", "Assert.NotNull(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Equal(null, data)|]",
+		/* lang=c#-test */ "Assert.Null(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.StrictEqual(null, data)|]",
+		/* lang=c#-test */ "Assert.Null(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotEqual(null, data)|]",
+		/* lang=c#-test */ "Assert.NotNull(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotStrictEqual(null, data)|]",
+		/* lang=c#-test */ "Assert.NotNull(data)")]
 	public async Task ConvertsToAppropriateNullAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualsShouldNotBeUsedFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualsShouldNotBeUsedFixerTests.cs
index 99e150d4..054dc878 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualsShouldNotBeUsedFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertEqualsShouldNotBeUsedFixerTests.cs
@@ -5,21 +5,26 @@
 
 public class AssertEqualsShouldNotBeUsedFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = 1;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = 1;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("{|CS0619:[|Assert.Equals(1, data)|]|}", "Assert.Equal(1, data)")]
-	[InlineData("{|CS0619:[|Assert.ReferenceEquals(1, data)|]|}", "Assert.Same(1, data)")]
+	[InlineData(
+		/* lang=c#-test */ "{|CS0619:[|Assert.Equals(1, data)|]|}",
+		/* lang=c#-test */ "Assert.Equal(1, data)")]
+	[InlineData(
+		/* lang=c#-test */ "{|CS0619:[|Assert.ReferenceEquals(1, data)|]|}",
+		/* lang=c#-test */ "Assert.Same(1, data)")]
 	public async Task ConvertsObjectCallToAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeFixerTests.cs
index 90da2c57..20e0a383 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertIsTypeShouldNotBeUsedForAbstractTypeFixerTests.cs
@@ -5,24 +5,33 @@
 
 public class AssertIsTypeShouldNotBeUsedForAbstractTypeFixerTests
 {
-	const string template = @"
-using System;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System;
+		using Xunit;
 
-public abstract class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = new object();
+		public abstract class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = new object();
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.IsType<IDisposable>(data)|]", "Assert.IsAssignableFrom<IDisposable>(data)")]
-	[InlineData("[|Assert.IsType<TestClass>(data)|]", "Assert.IsAssignableFrom<TestClass>(data)")]
-	[InlineData("[|Assert.IsNotType<IDisposable>(data)|]", "Assert.IsNotAssignableFrom<IDisposable>(data)")]
-	[InlineData("[|Assert.IsNotType<TestClass>(data)|]", "Assert.IsNotAssignableFrom<TestClass>(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.IsType<IDisposable>(data)|]",
+		/* lang=c#-test */ "Assert.IsAssignableFrom<IDisposable>(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.IsType<TestClass>(data)|]",
+		/* lang=c#-test */ "Assert.IsAssignableFrom<TestClass>(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.IsNotType<IDisposable>(data)|]",
+		/* lang=c#-test */ "Assert.IsNotAssignableFrom<IDisposable>(data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.IsNotType<TestClass>(data)|]",
+		/* lang=c#-test */ "Assert.IsNotAssignableFrom<TestClass>(data)")]
 	public async Task Conversions(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertNullShouldNotBeCalledOnValueTypesFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertNullShouldNotBeCalledOnValueTypesFixerTests.cs
index ab2cc807..7324379b 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertNullShouldNotBeCalledOnValueTypesFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertNullShouldNotBeCalledOnValueTypesFixerTests.cs
@@ -8,67 +8,71 @@ public class AssertNullShouldNotBeCalledOnValueTypesFixerTests
 	[Fact]
 	public async Task ForValueTypeNullAssert_RemovesAssertion()
 	{
-		const string before = @"
-using Xunit;
+		const string before = /* lang=c#-test */ """
+			using Xunit;
 
-public class Tests {
-    [Fact]
-    public void TestMethod() {
-        int i = 1;
+			public class Tests {
+			    [Fact]
+			    public void TestMethod() {
+			        int i = 1;
 
-        [|Assert.NotNull(i)|];
-    }
-}";
-		const string after = @"
-using Xunit;
+			        [|Assert.NotNull(i)|];
+			    }
+			}
+			""";
+		const string after = /* lang=c#-test */ """
+			using Xunit;
 
-public class Tests {
-    [Fact]
-    public void TestMethod() {
-        int i = 1;
-    }
-}";
+			public class Tests {
+			    [Fact]
+			    public void TestMethod() {
+			        int i = 1;
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, AssertNullShouldNotBeCalledOnValueTypesFixer.Key_RemoveAssert);
 	}
 
-	[Fact]
 	// https://github.com/xunit/xunit/issues/1753
+	[Fact]
 	public async Task ForAssertionWithTrivia_RemovesAssertionAndLeavesLeadingTriviaInPlace()
 	{
-		const string before = @"
-using System;
-using Xunit;
+		const string before = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-namespace XUnitTestProject1 {
-    public class UnitTest1 {
-        [Fact]
-        public void Test1() {
-            int i = 1;
+			namespace XUnitTestProject1 {
+			    public class UnitTest1 {
+			        [Fact]
+			        public void Test1() {
+			            int i = 1;
 
-            // I am a comment which gets deleted by the quick fix
-            // Assert
-            [|Assert.NotNull(i)|];
-            Assert.Null(null);
-        }
-    }
-}";
-		const string after = @"
-using System;
-using Xunit;
+			            // I am a comment which gets deleted by the quick fix
+			            // Assert
+			            [|Assert.NotNull(i)|];
+			            Assert.Null(null);
+			        }
+			    }
+			}
+			""";
+		const string after = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-namespace XUnitTestProject1 {
-    public class UnitTest1 {
-        [Fact]
-        public void Test1() {
-            int i = 1;
+			namespace XUnitTestProject1 {
+			    public class UnitTest1 {
+			        [Fact]
+			        public void Test1() {
+			            int i = 1;
 
-            // I am a comment which gets deleted by the quick fix
-            // Assert
-            Assert.Null(null);
-        }
-    }
-}";
+			            // I am a comment which gets deleted by the quick fix
+			            // Assert
+			            Assert.Null(null);
+			        }
+			    }
+			}
+			""";
 
 		await Verify.VerifyCodeFix(before, after, AssertNullShouldNotBeCalledOnValueTypesFixer.Key_RemoveAssert);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckFixerTests.cs
index 6a984669..cb658e88 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertRegexMatchShouldNotUseBoolLiteralCheckFixerTests.cs
@@ -5,22 +5,27 @@
 
 public class AssertRegexMatchShouldNotUseBoolLiteralCheckFixerTests
 {
-	const string template = @"
-using System.Text.RegularExpressions;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System.Text.RegularExpressions;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var result = ""foo bar baz"";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var result = "foo bar baz";
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData(@"[|Assert.True(Regex.IsMatch(result, ""foo (.*?) baz""))|]", @"Assert.Matches(""foo (.*?) baz"", result)")]
-	[InlineData(@"[|Assert.False(Regex.IsMatch(result, ""foo (.*?) baz""))|]", @"Assert.DoesNotMatch(""foo (.*?) baz"", result)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(Regex.IsMatch(result, ""foo (.*?) baz""))|]",
+		/* lang=c#-test */ @"Assert.Matches(""foo (.*?) baz"", result)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.False(Regex.IsMatch(result, ""foo (.*?) baz""))|]",
+		/* lang=c#-test */ @"Assert.DoesNotMatch(""foo (.*?) baz"", result)")]
 	public async Task ConvertsBooleanAssertToRegexAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertSameShouldNotBeCalledOnValueTypesFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertSameShouldNotBeCalledOnValueTypesFixerTests.cs
index cc18e7e8..b779fe2d 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertSameShouldNotBeCalledOnValueTypesFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertSameShouldNotBeCalledOnValueTypesFixerTests.cs
@@ -5,21 +5,26 @@
 
 public class AssertSameShouldNotBeCalledOnValueTypesFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = 1;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = 1;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData("[|Assert.Same(1, data)|]", "Assert.Equal(1, data)")]
-	[InlineData("[|Assert.NotSame(1, data)|]", "Assert.NotEqual(1, data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.Same(1, data)|]",
+		/* lang=c#-test */ "Assert.Equal(1, data)")]
+	[InlineData(
+		/* lang=c#-test */ "[|Assert.NotSame(1, data)|]",
+		/* lang=c#-test */ "Assert.NotEqual(1, data)")]
 	public async Task ConvertsSameToEqual(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertSingleShouldBeUsedForSingleParameterFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertSingleShouldBeUsedForSingleParameterFixerTests.cs
index ffebbb4e..442de3b0 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertSingleShouldBeUsedForSingleParameterFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertSingleShouldBeUsedForSingleParameterFixerTests.cs
@@ -9,118 +9,160 @@ public class AssertSingleShouldBeUsedForSingleParameterFixerTests
 	public static TheoryData<string, string> Statements = new()
 	{
 		{
-			"[|Assert.Collection(collection, item => Assert.NotNull(item))|]",
-			@"var item = Assert.Single(collection);
-        Assert.NotNull(item);"
+			/* lang=c#-test */ """
+			        [|Assert.Collection(collection, item => Assert.NotNull(item))|]
+			""",
+			/* lang=c#-test */ """
+			        var item = Assert.Single(collection);
+			        Assert.NotNull(item);
+			"""
 		},
 		{
-			@"var item = 42;
-        [|Assert.Collection(collection, item => Assert.NotNull(item))|]",
-			@"var item = 42;
-        var item_2 = Assert.Single(collection);
-        Assert.NotNull(item_2);"
+			/* lang=c#-test */ """
+			        var item = 42;
+			        [|Assert.Collection(collection, item => Assert.NotNull(item))|]
+			""",
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = Assert.Single(collection);
+			        Assert.NotNull(item_2);
+			"""
 		},
 		{
-			"[|Assert.Collection(collection, item => { Assert.NotNull(item); })|]",
-			@"var item = Assert.Single(collection);
-        Assert.NotNull(item);"
+			/* lang=c#-test */ """
+			        [|Assert.Collection(collection, item => { Assert.NotNull(item); })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = Assert.Single(collection);
+			        Assert.NotNull(item);
+			"""
 		},
 		{
-			@"var item = 42;
-        [|Assert.Collection(collection, item => { Assert.NotNull(item); })|]",
-			@"var item = 42;
-        var item_2 = Assert.Single(collection);
-        Assert.NotNull(item_2);"
+			/* lang=c#-test */ """
+			        var item = 42;
+			        [|Assert.Collection(collection, item => { Assert.NotNull(item); })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = Assert.Single(collection);
+			        Assert.NotNull(item_2);
+			"""
 		},
 		{
-			"[|Assert.Collection(collection, item => { Assert.NotNull(item); Assert.NotNull(item); })|]",
-			@"var item = Assert.Single(collection);
-        Assert.NotNull(item); Assert.NotNull(item);"
+			/* lang=c#-test */ """
+			        [|Assert.Collection(collection, item => { Assert.NotNull(item); Assert.NotNull(item); })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = Assert.Single(collection);
+			        Assert.NotNull(item); Assert.NotNull(item);
+			"""
 		},
 		{
-			@"var item = 42;
-        [|Assert.Collection(collection, item => { Assert.NotNull(item); Assert.NotNull(item); })|]",
-			@"var item = 42;
-        var item_2 = Assert.Single(collection);
-        Assert.NotNull(item_2); Assert.NotNull(item_2);"
+			/* lang=c#-test */ """
+			        var item = 42;
+			        [|Assert.Collection(collection, item => { Assert.NotNull(item); Assert.NotNull(item); })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = Assert.Single(collection);
+			        Assert.NotNull(item_2); Assert.NotNull(item_2);
+			"""
 		},
 		{
-			@"[|Assert.Collection(collection, item => {
-            if (item != null) {
-                Assert.NotNull(item);
-                Assert.NotNull(item);
-            }
-        })|]",
-			@"var item = Assert.Single(collection);
-        if (item != null)
-        {
-            Assert.NotNull(item);
-            Assert.NotNull(item);
-        }"
+			/* lang=c#-test */ """
+			        [|Assert.Collection(collection, item => {
+			            if (item != null) {
+			                Assert.NotNull(item);
+			                Assert.NotNull(item);
+			            }
+			        })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = Assert.Single(collection);
+			        if (item != null)
+			        {
+			            Assert.NotNull(item);
+			            Assert.NotNull(item);
+			        }
+			"""
 		},
 		{
-			@"var item = 42;
-        [|Assert.Collection(collection, item => {
-            if (item != null) {
-                Assert.NotNull(item);
-                Assert.NotNull(item);
-            }
-        })|]",
-			@"var item = 42;
-        var item_2 = Assert.Single(collection);
-        if (item_2 != null)
-        {
-            Assert.NotNull(item_2);
-            Assert.NotNull(item_2);
-        }"
+			/* lang=c#-test */ """
+			        var item = 42;
+			        [|Assert.Collection(collection, item => {
+			            if (item != null) {
+			                Assert.NotNull(item);
+			                Assert.NotNull(item);
+			            }
+			        })|]
+			""",
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = Assert.Single(collection);
+			        if (item_2 != null)
+			        {
+			            Assert.NotNull(item_2);
+			            Assert.NotNull(item_2);
+			        }
+			"""
 		},
 		{
-			"[|Assert.Collection(collection, ElementInspector)|]",
-			@"var item = Assert.Single(collection);
-        ElementInspector(item);"
+			/* lang=c#-test */ """
+			        [|Assert.Collection(collection, ElementInspector)|]
+			""",
+			/* lang=c#-test */ """
+			        var item = Assert.Single(collection);
+			        ElementInspector(item);
+			"""
 		},
 		{
-			@"var item = 42;
-        var item_2 = 21.12;
-        [|Assert.Collection(collection, ElementInspector)|]",
-			@"var item = 42;
-        var item_2 = 21.12;
-        var item_3 = Assert.Single(collection);
-        ElementInspector(item_3);"
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = 21.12;
+			        [|Assert.Collection(collection, ElementInspector)|]
+			""",
+			/* lang=c#-test */ """
+			        var item = 42;
+			        var item_2 = 21.12;
+			        var item_3 = Assert.Single(collection);
+			        ElementInspector(item_3);
+			"""
 		},
 	};
 
-	const string beforeTemplate = @"
-using Xunit;
-using System.Collections.Generic;
+	const string beforeTemplate = /* lang=c#-test */ """
+		using Xunit;
+		using System.Collections.Generic;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        IEnumerable<object> collection = new List<object>() {{ new object() }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        IEnumerable<object> collection = new List<object>() {{ new object() }};
 
-        {0};
-    }}
+		{0};
+		    }}
 
-    private void ElementInspector(object obj)
-    {{ }}
-}}";
+		    private void ElementInspector(object obj)
+		    {{ }}
+		}}
+		""";
 
-	const string afterTemplate = @"
-using Xunit;
-using System.Collections.Generic;
+	const string afterTemplate = /* lang=c#-test */ """
+		using Xunit;
+		using System.Collections.Generic;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        IEnumerable<object> collection = new List<object>() {{ new object() }};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        IEnumerable<object> collection = new List<object>() {{ new object() }};
 
-        {0}
-    }}
+		{0}
+		    }}
 
-    private void ElementInspector(object obj)
-    {{ }}
-}}";
+		    private void ElementInspector(object obj)
+		    {{ }}
+		}}
+		""";
 
 	[Theory]
 	[MemberData(nameof(Statements))]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckFixerTests.cs
index 8f04cf04..e9f9a839 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertStringEqualityCheckShouldNotUseBoolCheckFixerTests.cs
@@ -5,32 +5,49 @@
 
 public class AssertStringEqualityCheckShouldNotUseBoolCheckFixerTests
 {
-	const string template = @"
-using System;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = ""foo bar baz"";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = "foo bar baz";
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	// Instance Equals (true)
-	[InlineData(@"[|Assert.True(""foo bar baz"".Equals(data))|]", @"Assert.Equal(""foo bar baz"", data)")]
-	[InlineData(@"[|Assert.True(""foo bar baz"".Equals(data, StringComparison.Ordinal))|]", @"Assert.Equal(""foo bar baz"", data)")]
-	[InlineData(@"[|Assert.True(""foo bar baz"".Equals(data, StringComparison.OrdinalIgnoreCase))|]", @"Assert.Equal(""foo bar baz"", data, ignoreCase: true)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(""foo bar baz"".Equals(data))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(""foo bar baz"".Equals(data, StringComparison.Ordinal))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(""foo bar baz"".Equals(data, StringComparison.OrdinalIgnoreCase))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data, ignoreCase: true)")]
 	// Static Equals (true)
-	[InlineData(@"[|Assert.True(string.Equals(""foo bar baz"", data))|]", @"Assert.Equal(""foo bar baz"", data)")]
-	[InlineData(@"[|Assert.True(string.Equals(""foo bar baz"", data, StringComparison.Ordinal))|]", @"Assert.Equal(""foo bar baz"", data)")]
-	[InlineData(@"[|Assert.True(string.Equals(""foo bar baz"", data, StringComparison.OrdinalIgnoreCase))|]", @"Assert.Equal(""foo bar baz"", data, ignoreCase: true)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(string.Equals(""foo bar baz"", data))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(string.Equals(""foo bar baz"", data, StringComparison.Ordinal))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(string.Equals(""foo bar baz"", data, StringComparison.OrdinalIgnoreCase))|]",
+		/* lang=c#-test */ @"Assert.Equal(""foo bar baz"", data, ignoreCase: true)")]
 	// Instance Equals (false)
-	[InlineData(@"[|Assert.False(""foo bar baz"".Equals(data))|]", @"Assert.NotEqual(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.False(""foo bar baz"".Equals(data))|]",
+		/* lang=c#-test */ @"Assert.NotEqual(""foo bar baz"", data)")]
 	// Static Equals (false)
-	[InlineData(@"[|Assert.False(string.Equals(""foo bar baz"", data))|]", @"Assert.NotEqual(""foo bar baz"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.False(string.Equals(""foo bar baz"", data))|]",
+		/* lang=c#-test */ @"Assert.NotEqual(""foo bar baz"", data)")]
 	public async Task ConvertsBooleanAssertToEqualityAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertSubstringCheckShouldNotUseBoolCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertSubstringCheckShouldNotUseBoolCheckFixerTests.cs
index 8ec7c6c2..cda371ae 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertSubstringCheckShouldNotUseBoolCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertSubstringCheckShouldNotUseBoolCheckFixerTests.cs
@@ -5,26 +5,39 @@
 
 public class AssertSubstringCheckShouldNotUseBoolCheckFixerTests
 {
-	const string template = @"
-using System;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System;
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        var data = ""foo bar baz"";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        var data = "foo bar baz";
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData(@"[|Assert.True(data.Contains(""foo""))|]", @"Assert.Contains(""foo"", data)")]
-	[InlineData(@"[|Assert.True(data.StartsWith(""foo""))|]", @"Assert.StartsWith(""foo"", data)")]
-	[InlineData(@"[|Assert.True(data.StartsWith(""foo"", StringComparison.Ordinal))|]", @"Assert.StartsWith(""foo"", data, StringComparison.Ordinal)")]
-	[InlineData(@"[|Assert.True(data.EndsWith(""foo""))|]", @"Assert.EndsWith(""foo"", data)")]
-	[InlineData(@"[|Assert.True(data.EndsWith(""foo"", StringComparison.OrdinalIgnoreCase))|]", @"Assert.EndsWith(""foo"", data, StringComparison.OrdinalIgnoreCase)")]
-	[InlineData(@"[|Assert.False(data.Contains(""foo""))|]", @"Assert.DoesNotContain(""foo"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(data.Contains(""foo""))|]",
+		/* lang=c#-test */ @"Assert.Contains(""foo"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(data.StartsWith(""foo""))|]",
+		/* lang=c#-test */ @"Assert.StartsWith(""foo"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(data.StartsWith(""foo"", StringComparison.Ordinal))|]",
+		/* lang=c#-test */ @"Assert.StartsWith(""foo"", data, StringComparison.Ordinal)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(data.EndsWith(""foo""))|]",
+		/* lang=c#-test */ @"Assert.EndsWith(""foo"", data)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.True(data.EndsWith(""foo"", StringComparison.OrdinalIgnoreCase))|]",
+		/* lang=c#-test */ @"Assert.EndsWith(""foo"", data, StringComparison.OrdinalIgnoreCase)")]
+	[InlineData(
+		/* lang=c#-test */ @"[|Assert.False(data.Contains(""foo""))|]",
+		/* lang=c#-test */ @"Assert.DoesNotContain(""foo"", data)")]
 	public async Task ConvertsBooleanAssertToStringSpecificAssert(
 		string beforeAssert,
 		string afterAssert)
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckFixerTests.cs
index d395cb69..916cab3a 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AssertThrowsShouldNotBeUsedForAsyncThrowsCheckFixerTests.cs
@@ -8,48 +8,59 @@ public class AssertThrowsShouldNotBeUsedForAsyncThrowsCheckFixerTests
 {
 	public static readonly TheoryData<string, string> Assertions = GenerateAssertions();
 
-	static readonly string template = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using System;
+		using System.Threading.Tasks;
+		using Xunit;
 
-public class TestClass {{
-    Task ThrowingMethod() {{
-        throw new NotImplementedException();
-    }}
+		public class TestClass {{
+		    Task ThrowingMethod() {{
+		        throw new NotImplementedException();
+		    }}
 
-    [Fact]{0}
-}}";
+		    [Fact]{0}
+		}}
+		""";
 
 	static TheoryData<string, string> GenerateAssertions()
 	{
 		var templates = new (string, string)[]
 		{
-			("Assert.Throws(typeof(Exception), {0})", "Assert.ThrowsAsync(typeof(Exception), {0})"),
-			("Assert.Throws<Exception>({0})", "Assert.ThrowsAsync<Exception>({0})"),
-			("Assert.Throws<ArgumentException>(\"parameter\", {0})", "Assert.ThrowsAsync<ArgumentException>(\"parameter\", {0})"),
-			("Assert.ThrowsAny<Exception>({0})", "Assert.ThrowsAnyAsync<Exception>({0})"),
+			(
+				/* lang=c#-test */ "Assert.Throws(typeof(Exception), {0})",
+				/* lang=c#-test */ "Assert.ThrowsAsync(typeof(Exception), {0})"
+			),
+			(
+				/* lang=c#-test */ "Assert.Throws<Exception>({0})",
+				/* lang=c#-test */ "Assert.ThrowsAsync<Exception>({0})"
+			),
+			(
+				/* lang=c#-test */ "Assert.Throws<ArgumentException>(\"parameter\", {0})",
+				/* lang=c#-test */ "Assert.ThrowsAsync<ArgumentException>(\"parameter\", {0})"
+			),
+			(
+				/* lang=c#-test */ "Assert.ThrowsAny<Exception>({0})",
+				/* lang=c#-test */ "Assert.ThrowsAnyAsync<Exception>({0})"
+			),
 		};
 
 		var lambdas = new[]
 		{
-			"(Func<Task>)ThrowingMethod",
-			"() => Task.Delay(0)",
-			"(Func<Task>)(async () => await Task.Delay(0))",
-			"(Func<Task>)(async () => await Task.Delay(0).ConfigureAwait(false))",
+			/* lang=c#-test */ "(Func<Task>)ThrowingMethod",
+			/* lang=c#-test */ "() => Task.Delay(0)",
+			/* lang=c#-test */ "(Func<Task>)(async () => await Task.Delay(0))",
+			/* lang=c#-test */ "(Func<Task>)(async () => await Task.Delay(0).ConfigureAwait(false))",
 		};
 
 		var assertions = new TheoryData<string, string>();
 
 		foreach ((var assertionTemplate, var replacementTemplate) in templates)
-		{
 			foreach (var lambda in lambdas)
 			{
 				var assertion = string.Format(assertionTemplate, lambda);
 				var replacement = string.Format(replacementTemplate, lambda);
 				assertions.Add(assertion, replacement);
 			}
-		}
 
 		return assertions;
 	}
@@ -60,15 +71,16 @@ public async Task GivenAssertionInMethod_ReplacesWithAsyncAssertion(
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        {{|CS0619:[|{assertion}|]|}};
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        await {replacement};
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        {{|CS0619:[|{0}|]|}};
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        await {0};
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -79,27 +91,28 @@ public async Task GivenAssertionInInvokedAnonymousFunction_ReplacesWithAsyncAsse
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Func<int> function = () => {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }};
-
-        int number = function();
-        function();
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        Func<Task<int>> function = async () => {{
-            await {replacement};
-            return 0;
-        }};
-
-        int number = {{|CS0029:function()|}};
-        function();
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Func<int> function = () => {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }};
+
+			        int number = function();
+			        function();
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        Func<Task<int>> function = async () => {{
+			            await {0};
+			            return 0;
+			        }};
+
+			        int number = {{|CS0029:function()|}};
+			        function();
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -110,34 +123,35 @@ public async Task GivenAssertionInInvokedAnonymousFunctionWithAssignment_Replace
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Func<int> function = () => 0;
-        function = () => {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }};
-
-        int number = function();
-        function();
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        Func<Task<int>> function = () => {{|CS0029:{{|CS1662:0|}}|}};
-        function = async () => {{
-            await {replacement};
-            return 0;
-        }};
-
-        int number = {{|CS0029:function()|}};
-        function();
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Func<int> function = () => 0;
+			        function = () => {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }};
+
+			        int number = function();
+			        function();
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        Func<Task<int>> function = () => {{|CS0029:{{|CS1662:0|}}|}};
+			        function = async () => {{
+			            await {0};
+			            return 0;
+			        }};
+
+			        int number = {{|CS0029:function()|}};
+			        function();
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
 
-#if ROSLYN_4_4_OR_GREATER
+#if ROSLYN_4_4_OR_GREATER  // No C# 10 in Roslyn 3.11, so no anonymous lambda types
 
 	[Theory]
 	[MemberData(nameof(Assertions))]
@@ -145,27 +159,28 @@ public async Task GivenAssertionInInvokedAnonymousFunctionWithVar_ReplacesWithAs
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        var function = () => {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }};
-
-        int number = function();
-        function();
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        var function = async () => {{
-            await {replacement};
-            return 0;
-        }};
-
-        int number = {{|CS0029:function()|}};
-        function();
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        var function = () => {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }};
+
+			        int number = function();
+			        function();
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        var function = async () => {{
+			            await {0};
+			            return 0;
+			        }};
+
+			        int number = {{|CS0029:function()|}};
+			        function();
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp10, beforeMethod, afterMethod);
 	}
@@ -178,21 +193,22 @@ public async Task GivenAssertionInUninvokedAnonymousFunction_ReplacesWithAsyncAs
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Func<int> function = () => {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }};
-    }}";
-
-		var afterMethod = $@"
-    public void TestMethod() {{
-        Func<Task<int>> function = async () => {{
-            await {replacement};
-            return 0;
-        }};
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Func<int> function = () => {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }};
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Func<Task<int>> function = async () => {{
+			            await {0};
+			            return 0;
+			        }};
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -203,35 +219,36 @@ public async Task GivenAssertionInInvokedNestedAnonymousFunction_ReplacesWithAsy
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Action<int> outerFunction = (number) => {{
-            Func<string> innerFunction = delegate () {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }};
-
-            var message = innerFunction().ToLower();
-            innerFunction();
-        }};
-
-        outerFunction(0);
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        Func<int, Task> outerFunction = async (number) => {{
-            Func<Task<string>> innerFunction = async delegate () {{
-                await {replacement};
-                return string.Empty;
-            }};
-
-            var message = innerFunction().{{|CS7036:ToLower|}}();
-            innerFunction();
-        }};
-
-        outerFunction(0);
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Action<int> outerFunction = (number) => {{
+			            Func<string> innerFunction = delegate () {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction().ToLower();
+			            innerFunction();
+			        }};
+
+			        outerFunction(0);
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        Func<int, Task> outerFunction = async (number) => {{
+			            Func<Task<string>> innerFunction = async delegate () {{
+			                await {0};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction().{{|CS7036:ToLower|}}();
+			            innerFunction();
+			        }};
+
+			        outerFunction(0);
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -242,33 +259,34 @@ public async Task GivenAssertionInExplicitlyInvokedNestedAnonymousFunction_Repla
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Action<int> outerFunction = (number) => {{
-            Func<string> innerFunction = delegate () {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }};
-
-            var message = innerFunction.Invoke().ToLower();
-        }};
-
-        outerFunction.Invoke(0);
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        Func<int, Task> outerFunction = async (number) => {{
-            Func<Task<string>> innerFunction = async delegate () {{
-                await {replacement};
-                return string.Empty;
-            }};
-
-            var message = innerFunction.Invoke().{{|CS7036:ToLower|}}();
-        }};
-
-        outerFunction.Invoke(0);
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Action<int> outerFunction = (number) => {{
+			            Func<string> innerFunction = delegate () {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction.Invoke().ToLower();
+			        }};
+
+			        outerFunction.Invoke(0);
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        Func<int, Task> outerFunction = async (number) => {{
+			            Func<Task<string>> innerFunction = async delegate () {{
+			                await {0};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction.Invoke().{{|CS7036:ToLower|}}();
+			        }};
+
+			        outerFunction.Invoke(0);
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -279,33 +297,34 @@ public async Task GivenAssertionInConditionallyInvokedNestedAnonymousFunction_Re
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Action<int> outerFunction = (number) => {{
-            Func<string> innerFunction = delegate () {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }};
-
-            var message = innerFunction?.Invoke().ToLower();
-        }};
-
-        outerFunction?.Invoke(0);
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        Func<int, Task> outerFunction = async (number) => {{
-            Func<Task<string>> innerFunction = async delegate () {{
-                await {replacement};
-                return string.Empty;
-            }};
-
-            var message = innerFunction?.Invoke().{{|CS7036:ToLower|}}();
-        }};
-
-        outerFunction?.Invoke(0);
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Action<int> outerFunction = (number) => {{
+			            Func<string> innerFunction = delegate () {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction?.Invoke().ToLower();
+			        }};
+
+			        outerFunction?.Invoke(0);
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        Func<int, Task> outerFunction = async (number) => {{
+			            Func<Task<string>> innerFunction = async delegate () {{
+			                await {0};
+			                return string.Empty;
+			            }};
+
+			            var message = innerFunction?.Invoke().{{|CS7036:ToLower|}}();
+			        }};
+
+			        outerFunction?.Invoke(0);
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -316,25 +335,26 @@ public async Task GivenAssertionInUninvokedNestedAnonymousFunction_ReplacesWithA
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        Action<int> outerFunction = (number) => {{
-            Func<string> innerFunction = () => {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }};
-        }};
-    }}";
-
-		var afterMethod = $@"
-    public void TestMethod() {{
-        Action<int> outerFunction = (number) => {{
-            Func<Task<string>> innerFunction = async () => {{
-                await {replacement};
-                return string.Empty;
-            }};
-        }};
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Action<int> outerFunction = (number) => {{
+			            Func<string> innerFunction = () => {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }};
+			        }};
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        Action<int> outerFunction = (number) => {{
+			            Func<Task<string>> innerFunction = async () => {{
+			                await {0};
+			                return string.Empty;
+			            }};
+			        }};
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(beforeMethod, afterMethod);
 	}
@@ -345,27 +365,28 @@ public async Task GivenAssertionInInvokedLocalFunction_ReplacesWithAsyncAssertio
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        int number = Function();
-        Function();
-
-        int Function() {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }}
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        int number = {{|CS0029:Function()|}};
-        Function();
-
-        async Task<int> Function() {{
-            await {replacement};
-            return 0;
-        }}
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int number = Function();
+			        Function();
+
+			        int Function() {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }}
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        int number = {{|CS0029:Function()|}};
+			        Function();
+
+			        async Task<int> Function() {{
+			            await {0};
+			            return 0;
+			        }}
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp7, beforeMethod, afterMethod);
 	}
@@ -376,21 +397,22 @@ public async Task GivenAssertionInUninvokedLocalFunction_ReplacesWithAsyncAssert
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        int Function() {{
-            {{|CS0619:[|{assertion}|]|}};
-            return 0;
-        }}
-    }}";
-
-		var afterMethod = $@"
-    public void TestMethod() {{
-        async Task<int> Function() {{
-            await {replacement};
-            return 0;
-        }}
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int Function() {{
+			            {{|CS0619:[|{0}|]|}};
+			            return 0;
+			        }}
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        async Task<int> Function() {{
+			            await {0};
+			            return 0;
+			        }}
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp7, beforeMethod, afterMethod);
 	}
@@ -401,39 +423,40 @@ public async Task GivenAssertionInInvokedNestedLocalFunction_ReplacesWithAsyncAs
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        int number = OuterFunction();
-        OuterFunction();
-
-        int OuterFunction() {{
-            var message = InnerFunction().ToLower();
-            InnerFunction();
-            return 0;
-
-            string InnerFunction() {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }}
-        }}
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        int number = {{|CS0029:OuterFunction()|}};
-        OuterFunction();
-
-        async Task<int> OuterFunction() {{
-            var message = InnerFunction().{{|CS7036:ToLower|}}();
-            InnerFunction();
-            return 0;
-
-            async Task<string> InnerFunction() {{
-                await {replacement};
-                return string.Empty;
-            }}
-        }}
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int number = OuterFunction();
+			        OuterFunction();
+
+			        int OuterFunction() {{
+			            var message = InnerFunction().ToLower();
+			            InnerFunction();
+			            return 0;
+
+			            string InnerFunction() {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }}
+			        }}
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        int number = {{|CS0029:OuterFunction()|}};
+			        OuterFunction();
+
+			        async Task<int> OuterFunction() {{
+			            var message = InnerFunction().{{|CS7036:ToLower|}}();
+			            InnerFunction();
+			            return 0;
+
+			            async Task<string> InnerFunction() {{
+			                await {0};
+			                return string.Empty;
+			            }}
+			        }}
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp7, beforeMethod, afterMethod);
 	}
@@ -444,29 +467,30 @@ public async Task GivenAssertionInUninvokedNestedLocalFunction_ReplacesWithAsync
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        int OuterFunction() {{
-            return 0;
-
-            string InnerFunction() {{
-                {{|CS0619:[|{assertion}|]|}};
-                return string.Empty;
-            }}
-        }}
-    }}";
-
-		var afterMethod = $@"
-    public void TestMethod() {{
-        int OuterFunction() {{
-            return 0;
-
-            async Task<string> InnerFunction() {{
-                await {replacement};
-                return string.Empty;
-            }}
-        }}
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int OuterFunction() {{
+			            return 0;
+
+			            string InnerFunction() {{
+			                {{|CS0619:[|{0}|]|}};
+			                return string.Empty;
+			            }}
+			        }}
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int OuterFunction() {{
+			            return 0;
+
+			            async Task<string> InnerFunction() {{
+			                await {0};
+			                return string.Empty;
+			            }}
+			        }}
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp7, beforeMethod, afterMethod);
 	}
@@ -477,59 +501,60 @@ public async Task GivenAssertionInMixedNestedFunctions_ReplacesWithAsyncAssertio
 		string assertion,
 		string replacement)
 	{
-		var beforeMethod = $@"
-    public void TestMethod() {{
-        int OuterLocalFunction() {{
-            Func<bool> outerAnonymousFunction = () => {{
-                string InnerLocalFunction() {{
-                    Action innerAnonymousFunction = () => {{
-                        {{|CS0619:[|{assertion}|]|}};
-                    }};
-
-                    innerAnonymousFunction();
-                    return string.Empty;
-                }}
-
-                string message = InnerLocalFunction();
-                InnerLocalFunction();
-                return false;
-            }};
-
-            bool condition = outerAnonymousFunction();
-            outerAnonymousFunction();
-            return 0;
-        }}
-
-        int number = OuterLocalFunction();
-        OuterLocalFunction();
-    }}";
-
-		var afterMethod = $@"
-    public async Task TestMethod() {{
-        async Task<int> OuterLocalFunction() {{
-            Func<Task<bool>> outerAnonymousFunction = async () => {{
-                async Task<string> InnerLocalFunction() {{
-                    Func<Task> innerAnonymousFunction = async () => {{
-                        await {replacement};
-                    }};
-
-                    innerAnonymousFunction();
-                    return string.Empty;
-                }}
-
-                string message = {{|CS0029:InnerLocalFunction()|}};
-                InnerLocalFunction();
-                return false;
-            }};
-
-            bool condition = {{|CS0029:outerAnonymousFunction()|}};
-            outerAnonymousFunction();
-            return 0;
-        }}
-
-        int number = {{|CS0029:OuterLocalFunction()|}};
-        OuterLocalFunction();
-    }}";
+		var beforeMethod = string.Format(/* lang=c#-test */ """
+			    public void TestMethod() {{
+			        int OuterLocalFunction() {{
+			            Func<bool> outerAnonymousFunction = () => {{
+			                string InnerLocalFunction() {{
+			                    Action innerAnonymousFunction = () => {{
+			                        {{|CS0619:[|{0}|]|}};
+			                    }};
+
+			                    innerAnonymousFunction();
+			                    return string.Empty;
+			                }}
+
+			                string message = InnerLocalFunction();
+			                InnerLocalFunction();
+			                return false;
+			            }};
+
+			            bool condition = outerAnonymousFunction();
+			            outerAnonymousFunction();
+			            return 0;
+			        }}
+
+			        int number = OuterLocalFunction();
+			        OuterLocalFunction();
+			    }}
+			""", assertion);
+		var afterMethod = string.Format(/* lang=c#-test */ """
+			    public async Task TestMethod() {{
+			        async Task<int> OuterLocalFunction() {{
+			            Func<Task<bool>> outerAnonymousFunction = async () => {{
+			                async Task<string> InnerLocalFunction() {{
+			                    Func<Task> innerAnonymousFunction = async () => {{
+			                        await {0};
+			                    }};
+
+			                    innerAnonymousFunction();
+			                    return string.Empty;
+			                }}
+
+			                string message = {{|CS0029:InnerLocalFunction()|}};
+			                InnerLocalFunction();
+			                return false;
+			            }};
+
+			            bool condition = {{|CS0029:outerAnonymousFunction()|}};
+			            outerAnonymousFunction();
+			            return 0;
+			        }}
+
+			        int number = {{|CS0029:OuterLocalFunction()|}};
+			        OuterLocalFunction();
+			    }}
+			""", replacement);
 
 		await VerifyCodeFix(LanguageVersion.CSharp7, beforeMethod, afterMethod);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/AsyncAssertsShouldBeAwaitedFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/AsyncAssertsShouldBeAwaitedFixerTests.cs
index aa015570..9d3543c6 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/AsyncAssertsShouldBeAwaitedFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/AsyncAssertsShouldBeAwaitedFixerTests.cs
@@ -6,31 +6,32 @@
 
 public class AsyncAssertsShouldBeAwaitedFixerTests
 {
-	string codeTemplate = @"
-using System;
-using System.ComponentModel;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass : INotifyPropertyChanged {{
-    public int Property {{ get; set; }}
-
-    public event PropertyChangedEventHandler? PropertyChanged;
-    public event EventHandler? SimpleEvent;
-    public event EventHandler<int>? SimpleIntEvent;
-
-    [Fact]
-    public void TestMethod() {{
-        {0}
-    }}
-}}
-
-public static class MyTaskExtensions {{
-    public static void ConsumeTask(this Task t) {{ }}
-}}";
-
-	public static TheoryData<string> AsyncAssertions = new()
-	{
+	const string codeTemplate = /* lang=c#-test */ """
+		using System;
+		using System.ComponentModel;
+		using System.Threading.Tasks;
+		using Xunit;
+
+		public class TestClass : INotifyPropertyChanged {{
+		    public int Property {{ get; set; }}
+
+		    public event PropertyChangedEventHandler? PropertyChanged;
+		    public event EventHandler? SimpleEvent;
+		    public event EventHandler<int>? SimpleIntEvent;
+
+		    [Fact]
+		    public void TestMethod() {{
+		        {0}
+		    }}
+		}}
+
+		public static class MyTaskExtensions {{
+		    public static void ConsumeTask(this Task t) {{ }}
+		}}
+		""";
+
+	public static TheoryData<string> AsyncAssertions =
+	[
 		"Assert.PropertyChangedAsync(this, nameof(Property), async () => throw new DivideByZeroException())",
 		"Assert.RaisesAnyAsync(eh => SimpleEvent += eh, eh => SimpleEvent -= eh, async () => throw new DivideByZeroException())",
 		"Assert.RaisesAnyAsync<int>(eh => SimpleIntEvent += eh, eh => SimpleIntEvent -= eh, async () => throw new DivideByZeroException())",
@@ -39,7 +40,7 @@ public static void ConsumeTask(this Task t) {{ }}
 		"Assert.ThrowsAsync(typeof(DivideByZeroException), async () => throw new DivideByZeroException())",
 		"Assert.ThrowsAsync<DivideByZeroException>(async () => throw new DivideByZeroException())",
 		"Assert.ThrowsAsync<ArgumentException>(\"argName\", async () => throw new DivideByZeroException())",
-	};
+	];
 
 	[Theory]
 	[MemberData(nameof(AsyncAssertions))]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeNegatedFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeNegatedFixerTests.cs
index 06073e90..0c14f905 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeNegatedFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeNegatedFixerTests.cs
@@ -5,17 +5,18 @@
 
 public class BooleanAssertsShouldNotBeNegatedFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        bool condition = true;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        bool condition = true;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
 	[InlineData("False", "True")]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckBooleanFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckBooleanFixerTests.cs
index a326bcca..f82a26ad 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckBooleanFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckBooleanFixerTests.cs
@@ -5,39 +5,40 @@
 
 public class BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckBooleanFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        bool condition = true;
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        bool condition = true;
 
-        {0};
-    }}
-}}";
+		        {0};
+		    }}
+		}}
+		""";
 
 	public static TheoryData<string, string, string> AssertExpressionReplacement = new()
 	{
-		{ "True", "condition == true", "True" },
-		{ "True", "condition != true", "False" },
-		{ "True", "true == condition", "True" },
-		{ "True", "true != condition", "False" },
+		/* lang=c#-test */ { "True", "condition == true", "True" },
+		/* lang=c#-test */ { "True", "condition != true", "False" },
+		/* lang=c#-test */ { "True", "true == condition", "True" },
+		/* lang=c#-test */ { "True", "true != condition", "False" },
 
-		{ "True", "condition == false", "False" },
-		{ "True", "condition != false", "True" },
-		{ "True", "false == condition", "False" },
-		{ "True", "false != condition", "True" },
+		/* lang=c#-test */ { "True", "condition == false", "False" },
+		/* lang=c#-test */ { "True", "condition != false", "True" },
+		/* lang=c#-test */ { "True", "false == condition", "False" },
+		/* lang=c#-test */ { "True", "false != condition", "True" },
 
-		{ "False", "condition == true", "False" },
-		{ "False", "condition != true", "True" },
-		{ "False", "true == condition", "False" },
-		{ "False", "true != condition", "True" },
+		/* lang=c#-test */ { "False", "condition == true", "False" },
+		/* lang=c#-test */ { "False", "condition != true", "True" },
+		/* lang=c#-test */ { "False", "true == condition", "False" },
+		/* lang=c#-test */ { "False", "true != condition", "True" },
 
-		{ "False", "condition == false", "True" },
-		{ "False", "condition != false", "False" },
-		{ "False", "false == condition", "True" },
-		{ "False", "false != condition", "False" },
+		/* lang=c#-test */ { "False", "condition == false", "True" },
+		/* lang=c#-test */ { "False", "condition != false", "False" },
+		/* lang=c#-test */ { "False", "false == condition", "True" },
+		/* lang=c#-test */ { "False", "false != condition", "False" },
 	};
 
 	[Theory]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckNonBooleanFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckNonBooleanFixerTests.cs
index 44c51e3b..37410f78 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckNonBooleanFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckNonBooleanFixerTests.cs
@@ -7,25 +7,26 @@
 
 public class BooleanAssertsShouldNotBeUsedForSimpleEqualityCheckNonBooleanFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+		using Xunit;
 
-public enum MyEnum {{ None, Bacon, Veggie }}
+		public enum MyEnum {{ None, Bacon, Veggie }}
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        {0} value = {1};
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        {0} value = {1};
 
-        {2};
-    }}
-}}";
+		        {2};
+		    }}
+		}}
+		""";
 
 	public static MatrixTheoryData<string, string, string> MethodOperatorValue =
 		new(
-			new[] { Constants.Asserts.True, Constants.Asserts.False },
-			new[] { "==", "!=" },
-			new[] { "\"bacon\"", "'5'", "5", "5l", "5.0d", "5.0f", "5.0m", "MyEnum.Bacon" }
+			[Constants.Asserts.True, Constants.Asserts.False],
+			["==", "!="],
+			["\"bacon\"", "'5'", "5", "5l", "5.0d", "5.0f", "5.0m", "MyEnum.Bacon"]
 		);
 
 	[Theory]
@@ -59,9 +60,9 @@ await Verify.VerifyCodeFix(
 
 	public static MatrixTheoryData<string, string, string> MethodOperatorType =
 		new(
-			new[] { Constants.Asserts.True, Constants.Asserts.False },
-			new[] { "==", "!=" },
-			new[] { "string", "int", "object", "MyEnum" }
+			[Constants.Asserts.True, Constants.Asserts.False],
+			["==", "!="],
+			["string", "int", "object", "MyEnum"]
 		);
 
 	[Theory]
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/UseAssertFailInsteadOfBooleanAssertFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/UseAssertFailInsteadOfBooleanAssertFixerTests.cs
index ac7f6612..3c4b1507 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/UseAssertFailInsteadOfBooleanAssertFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/UseAssertFailInsteadOfBooleanAssertFixerTests.cs
@@ -5,19 +5,21 @@
 
 public class UseAssertFailInsteadOfBooleanAssertFixerTests
 {
-	const string template = @"
-using Xunit;
+	const string template = /* lang=c#-test */ """
+
+		using Xunit;
 
-public class TestClass {{
-    [Fact]
-    public void TestMethod() {{
-        {0};
-    }}
-}}";
+		public class TestClass {{
+		    [Fact]
+		    public void TestMethod() {{
+		        {0};
+		    }}
+		}}
+		""";
 
 	[Theory]
-	[InlineData(@"[|Assert.True(false, ""message"")|]")]
-	[InlineData(@"[|Assert.False(true, ""message"")|]")]
+	[InlineData(/* lang=c#-test */ @"[|Assert.True(false, ""message"")|]")]
+	[InlineData(/* lang=c#-test */ @"[|Assert.False(true, ""message"")|]")]
 	public async Task ReplacesBooleanAssert(string badAssert)
 	{
 		var before = string.Format(template, badAssert);
diff --git a/src/xunit.analyzers.tests/Fixes/X2000/UseGenericOverloadFixTests.cs b/src/xunit.analyzers.tests/Fixes/X2000/UseGenericOverloadFixTests.cs
index ebeb600e..3baea676 100644
--- a/src/xunit.analyzers.tests/Fixes/X2000/UseGenericOverloadFixTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X2000/UseGenericOverloadFixTests.cs
@@ -9,29 +9,30 @@ public class UseGenericOverloadFixTests
 	[Fact]
 	public async Task X2007_SwitchesToGenericIsType()
 	{
-		var before = @"
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var result = 123;
+		var before = /* lang=c#-test */ """
+			using Xunit;
 
-        [|Assert.IsType(typeof(int), result)|];
-    }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        var result = 123;
 
-		var after = @"
-using Xunit;
+			        [|Assert.IsType(typeof(int), result)|];
+			    }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        var result = 123;
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        var result = 123;
 
-        Assert.IsType<int>(result);
-    }
-}";
+			        Assert.IsType<int>(result);
+			    }
+			}
+			""";
 
 		await Verify_X2007.VerifyCodeFix(before, after, UseGenericOverloadFix.Key_UseAlternateAssert);
 	}
@@ -39,31 +40,32 @@ public void TestMethod() {
 	[Fact]
 	public async Task X2015_SwitchesToGenericThrows()
 	{
-		var before = @"
-using System;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Action func = () => { };
+		var before = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-        [|Assert.Throws(typeof(DivideByZeroException), func)|];
-    }
-}";
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        Action func = () => { };
 
-		var after = @"
-using System;
-using Xunit;
+			        [|Assert.Throws(typeof(DivideByZeroException), func)|];
+			    }
+			}
+			""";
+		var after = /* lang=c#-test */ """
+			using System;
+			using Xunit;
 
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        Action func = () => { };
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        Action func = () => { };
 
-        Assert.Throws<DivideByZeroException>(func);
-    }
-}";
+			        Assert.Throws<DivideByZeroException>(func);
+			    }
+			}
+			""";
 
 		await Verify_X2015.VerifyCodeFix(before, after, UseGenericOverloadFix.Key_UseAlternateAssert);
 	}
diff --git a/src/xunit.analyzers.tests/Fixes/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests.cs
index ed55c51f..cbd3c7e0 100644
--- a/src/xunit.analyzers.tests/Fixes/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X3000/CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests.cs
@@ -11,13 +11,13 @@ public class CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests
 {
 	public class WithAbstractions : CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectFixerTests
 	{
-		readonly static string Template = "using Xunit.Abstractions; public class {0}: {1} {{ }}";
+		const string Template = /* lang=c#-test */ "using Xunit.Abstractions; public class {0}: {1} {{ }}";
 
 		[Theory]
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithAbstractions.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithAbstractions))]
 		public async Task DoesNotAttemptToFix(string @interface)
 		{
-			var source = string.Format(Template, "[|MyClass|]", @interface);
+			var source = string.Format(Template, /* lang=c#-test */ "[|MyClass|]", @interface);
 
 			await Verify_WithAbstractions.VerifyCodeFixV2(
 				source,
@@ -35,23 +35,25 @@ protected override XunitContext CreateXunitContext(Compilation compilation) =>
 
 	public class WithExecution
 	{
-		static string Template_WithoutUsing = @"
-using Xunit.Abstractions;
+		const string Template_WithoutUsing = /* lang=c#-test */ """
+			using Xunit.Abstractions;
 
-public class Foo {{ }}
-public class {0}: {1} {{ }}";
-		static string Template_WithUsing = @"
-using Xunit;
-using Xunit.Abstractions;
+			public class Foo {{ }}
+			public class {0}: {1} {{ }}
+			""";
+		const string Template_WithUsing = /* lang=c#-test */ """
+			using Xunit;
+			using Xunit.Abstractions;
 
-public class Foo {{ }}
-public class {0}: {1} {{ }}";
+			public class Foo {{ }}
+			public class {0}: {1} {{ }}
+			""";
 
 		[Theory]
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution))]
 		public async Task WithNoBaseClass_WithoutUsing_AddsBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithoutUsing, "[|MyClass|]", @interface);
+			var before = string.Format(Template_WithoutUsing, /* lang=c#-test */ "[|MyClass|]", @interface);
 			var after = string.Format(Template_WithoutUsing, "MyClass", $"Xunit.LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithExecution.VerifyCodeFixV2(
@@ -65,7 +67,7 @@ await Verify_WithExecution.VerifyCodeFixV2(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution))]
 		public async Task WithNoBaseClass_WithUsing_AddsBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithUsing, "[|MyClass|]", @interface);
+			var before = string.Format(Template_WithUsing, /* lang=c#-test */ "[|MyClass|]", @interface);
 			var after = string.Format(Template_WithUsing, "MyClass", $"LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithExecution.VerifyCodeFixV2(
@@ -79,7 +81,7 @@ await Verify_WithExecution.VerifyCodeFixV2(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution))]
 		public async Task WithBadBaseClass_WithoutUsing_ReplacesBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithoutUsing, "[|MyClass|]", $"Foo, {@interface}");
+			var before = string.Format(Template_WithoutUsing, /* lang=c#-test */ "[|MyClass|]", $"Foo, {@interface}");
 			var after = string.Format(Template_WithoutUsing, "MyClass", $"Xunit.LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithExecution.VerifyCodeFixV2(
@@ -93,7 +95,7 @@ await Verify_WithExecution.VerifyCodeFixV2(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithExecution))]
 		public async Task WithBadBaseClass_WithUsing_ReplacesBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithUsing, "[|MyClass|]", $"Foo, {@interface}");
+			var before = string.Format(Template_WithUsing, /* lang=c#-test */ "[|MyClass|]", $"Foo, {@interface}");
 			var after = string.Format(Template_WithUsing, "MyClass", $"LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithExecution.VerifyCodeFixV2(
@@ -112,23 +114,25 @@ protected override XunitContext CreateXunitContext(Compilation compilation) =>
 
 	public class WithRunnerUtility
 	{
-		static string Template_WithoutUsing = @"
-using Xunit.Abstractions;
+		const string Template_WithoutUsing = /* lang=c#-test */ """
+			using Xunit.Abstractions;
 
-public class Foo {{ }}
-public class {0}: {1} {{ }}";
-		static string Template_WithUsing = @"
-using Xunit.Abstractions;
-using Xunit.Sdk;
+			public class Foo {{ }}
+			public class {0}: {1} {{ }}
+			""";
+		const string Template_WithUsing = /* lang=c#-test */ """
+			using Xunit.Abstractions;
+			using Xunit.Sdk;
 
-public class Foo {{ }}
-public class {0}: {1} {{ }}";
+			public class Foo {{ }}
+			public class {0}: {1} {{ }}
+			""";
 
 		[Theory]
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility))]
 		public async Task WithNoBaseClass_WithoutUsing_AddsBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithoutUsing, "[|MyClass|]", @interface);
+			var before = string.Format(Template_WithoutUsing, /* lang=c#-test */ "[|MyClass|]", @interface);
 			var after = string.Format(Template_WithoutUsing, "MyClass", $"Xunit.Sdk.LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
@@ -142,7 +146,7 @@ await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility))]
 		public async Task WithNoBaseClass_WithUsing_AddsBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithUsing, "[|MyClass|]", @interface);
+			var before = string.Format(Template_WithUsing, /* lang=c#-test */ "[|MyClass|]", @interface);
 			var after = string.Format(Template_WithUsing, "MyClass", $"LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
@@ -156,7 +160,7 @@ await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility))]
 		public async Task WithBadBaseClass_WithoutUsing_ReplacesBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithoutUsing, "[|MyClass|]", $"Foo, {@interface}");
+			var before = string.Format(Template_WithoutUsing, /* lang=c#-test */ "[|MyClass|]", $"Foo, {@interface}");
 			var after = string.Format(Template_WithoutUsing, "MyClass", $"Xunit.Sdk.LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
@@ -170,7 +174,7 @@ await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
 		[MemberData(nameof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility.Interfaces), MemberType = typeof(CrossAppDomainClassesMustBeLongLivedMarshalByRefObjectTests.WithRunnerUtility))]
 		public async Task WithBadBaseClass_WithUsing_ReplacesBaseClass(string @interface)
 		{
-			var before = string.Format(Template_WithUsing, "[|MyClass|]", $"Foo, {@interface}");
+			var before = string.Format(Template_WithUsing, /* lang=c#-test */ "[|MyClass|]", $"Foo, {@interface}");
 			var after = string.Format(Template_WithUsing, "MyClass", $"LongLivedMarshalByRefObject, {@interface}");
 
 			await Verify_WithRunnerUtility.VerifyCodeFixV2RunnerUtility(
diff --git a/src/xunit.analyzers.tests/Fixes/X3000/SerializableClassMustHaveParameterlessConstructorFixerTests.cs b/src/xunit.analyzers.tests/Fixes/X3000/SerializableClassMustHaveParameterlessConstructorFixerTests.cs
index 66970f81..39482163 100644
--- a/src/xunit.analyzers.tests/Fixes/X3000/SerializableClassMustHaveParameterlessConstructorFixerTests.cs
+++ b/src/xunit.analyzers.tests/Fixes/X3000/SerializableClassMustHaveParameterlessConstructorFixerTests.cs
@@ -8,26 +8,27 @@ public class SerializableClassMustHaveParameterlessConstructorFixerTests
 	[Fact]
 	public async Task WithPublicParameteredConstructor_AddsNewConstructor()
 	{
-		var beforeTemplate = @"
-public class [|MyTestCase|]: {0}.IXunitSerializable {{
-    public MyTestCase(int x) {{ }}
-
-    void {0}.IXunitSerializable.Deserialize({0}.IXunitSerializationInfo _) {{ }}
-    void {0}.IXunitSerializable.Serialize({0}.IXunitSerializationInfo _) {{ }}
-}}";
-
-		var afterTemplate = @"
-public class MyTestCase: {0}.IXunitSerializable {{
-    [System.Obsolete(""Called by the de-serializer; should only be called by deriving classes for de-serialization purposes"")]
-    public MyTestCase()
-    {{
-    }}
-
-    public MyTestCase(int x) {{ }}
-
-    void {0}.IXunitSerializable.Deserialize({0}.IXunitSerializationInfo _) {{ }}
-    void {0}.IXunitSerializable.Serialize({0}.IXunitSerializationInfo _) {{ }}
-}}";
+		var beforeTemplate = /* lang=c#-test */ """
+			public class [|MyTestCase|]: {0}.IXunitSerializable {{
+			    public MyTestCase(int x) {{ }}
+
+			    void {0}.IXunitSerializable.Deserialize({0}.IXunitSerializationInfo _) {{ }}
+			    void {0}.IXunitSerializable.Serialize({0}.IXunitSerializationInfo _) {{ }}
+			}}
+			""";
+		var afterTemplate = /* lang=c#-test */ """
+			public class MyTestCase: {0}.IXunitSerializable {{
+			    [System.Obsolete("Called by the de-serializer; should only be called by deriving classes for de-serialization purposes")]
+			    public MyTestCase()
+			    {{
+			    }}
+
+			    public MyTestCase(int x) {{ }}
+
+			    void {0}.IXunitSerializable.Deserialize({0}.IXunitSerializationInfo _) {{ }}
+			    void {0}.IXunitSerializable.Serialize({0}.IXunitSerializationInfo _) {{ }}
+			}}
+			""";
 
 		var v2Before = string.Format(beforeTemplate, "Xunit.Abstractions");
 		var v2After = string.Format(afterTemplate, "Xunit.Abstractions");
@@ -43,26 +44,27 @@ public MyTestCase(int x) {{ }}
 	[Fact]
 	public async Task WithNonPublicParameterlessConstructor_ChangesVisibility_WithoutUsing()
 	{
-		var beforeTemplate = @"
-using {0};
+		var beforeTemplate = /* lang=c#-test */ """
+			using {0};
 
-public class [|MyTestCase|]: IXunitSerializable {{
-    protected MyTestCase() {{ throw new System.DivideByZeroException(); }}
+			public class [|MyTestCase|]: IXunitSerializable {{
+			    protected MyTestCase() {{ throw new System.DivideByZeroException(); }}
 
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
+		var afterTemplate = /* lang=c#-test */ """
+			using {0};
 
-		var afterTemplate = @"
-using {0};
+			public class MyTestCase: IXunitSerializable {{
+			    [System.Obsolete("Called by the de-serializer; should only be called by deriving classes for de-serialization purposes")]
+			    public MyTestCase() {{ throw new System.DivideByZeroException(); }}
 
-public class MyTestCase: IXunitSerializable {{
-    [System.Obsolete(""Called by the de-serializer; should only be called by deriving classes for de-serialization purposes"")]
-    public MyTestCase() {{ throw new System.DivideByZeroException(); }}
-
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
 
 		var v2Before = string.Format(beforeTemplate, "Xunit.Abstractions");
 		var v2After = string.Format(afterTemplate, "Xunit.Abstractions");
@@ -78,28 +80,29 @@ void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
 	[Fact]
 	public async Task WithNonPublicParameterlessConstructor_ChangesVisibility_WithUsing()
 	{
-		var beforeTemplate = @"
-using System;
-using {0};
-
-public class [|MyTestCase|]: IXunitSerializable {{
-    protected MyTestCase() {{ throw new DivideByZeroException(); }}
-
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
-
-		var afterTemplate = @"
-using System;
-using {0};
-
-public class MyTestCase: IXunitSerializable {{
-    [Obsolete(""Called by the de-serializer; should only be called by deriving classes for de-serialization purposes"")]
-    public MyTestCase() {{ throw new DivideByZeroException(); }}
-
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
+		var beforeTemplate = /* lang=c#-test */ """
+			using System;
+			using {0};
+
+			public class [|MyTestCase|]: IXunitSerializable {{
+			    protected MyTestCase() {{ throw new DivideByZeroException(); }}
+
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
+		var afterTemplate = /* lang=c#-test */ """
+			using System;
+			using {0};
+
+			public class MyTestCase: IXunitSerializable {{
+			    [Obsolete("Called by the de-serializer; should only be called by deriving classes for de-serialization purposes")]
+			    public MyTestCase() {{ throw new DivideByZeroException(); }}
+
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
 
 		var v2Before = string.Format(beforeTemplate, "Xunit.Abstractions");
 		var v2After = string.Format(afterTemplate, "Xunit.Abstractions");
@@ -115,29 +118,30 @@ void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
 	[Fact]
 	public async Task PreservesExistingObsoleteAttribute()
 	{
-		var beforeTemplate = @"
-using {0};
-using obo = System.ObsoleteAttribute;
-
-public class [|MyTestCase|]: IXunitSerializable {{
-    [obo(""This is my custom obsolete message"")]
-    protected MyTestCase() {{ throw new System.DivideByZeroException(); }}
-
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
-
-		var afterTemplate = @"
-using {0};
-using obo = System.ObsoleteAttribute;
-
-public class MyTestCase: IXunitSerializable {{
-    [obo(""This is my custom obsolete message"")]
-    public MyTestCase() {{ throw new System.DivideByZeroException(); }}
-
-    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
-    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
-}}";
+		var beforeTemplate = /* lang=c#-test */ """
+			using {0};
+			using obo = System.ObsoleteAttribute;
+
+			public class [|MyTestCase|]: IXunitSerializable {{
+			    [obo("This is my custom obsolete message")]
+			    protected MyTestCase() {{ throw new System.DivideByZeroException(); }}
+
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
+		var afterTemplate = /* lang=c#-test */ """
+			using {0};
+			using obo = System.ObsoleteAttribute;
+
+			public class MyTestCase: IXunitSerializable {{
+			    [obo("This is my custom obsolete message")]
+			    public MyTestCase() {{ throw new System.DivideByZeroException(); }}
+
+			    void IXunitSerializable.Deserialize(IXunitSerializationInfo _) {{ }}
+			    void IXunitSerializable.Serialize(IXunitSerializationInfo _) {{ }}
+			}}
+			""";
 
 		var v2Before = string.Format(beforeTemplate, "Xunit.Abstractions");
 		var v2After = string.Format(afterTemplate, "Xunit.Abstractions");
diff --git a/src/xunit.analyzers.tests/Suppressors/ConsiderCallingConfigureAwaitSuppressorTests.cs b/src/xunit.analyzers.tests/Suppressors/ConsiderCallingConfigureAwaitSuppressorTests.cs
index 4b246269..4c6d0a69 100644
--- a/src/xunit.analyzers.tests/Suppressors/ConsiderCallingConfigureAwaitSuppressorTests.cs
+++ b/src/xunit.analyzers.tests/Suppressors/ConsiderCallingConfigureAwaitSuppressorTests.cs
@@ -1,7 +1,6 @@
 #if NETCOREAPP
 
 using System.Threading.Tasks;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Testing;
 using Xunit;
@@ -13,14 +12,15 @@ public sealed class ConsiderCallingConfigureAwaitSuppressorTests
 	[Fact]
 	public async Task NonTestMethod_DoesNotSuppress()
 	{
-		var code = @"
-using System.Threading.Tasks;
+		var code = /* lang=c#-test */ """
+			using System.Threading.Tasks;
 
-public class NonTestClass {
-    public async Task NonTestMethod() {
-        await {|CA2007:Task.Delay(1)|};
-    }
-}";
+			public class NonTestClass {
+			    public async Task NonTestMethod() {
+			        await {|CA2007:Task.Delay(1)|};
+			    }
+			}
+			""";
 
 		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA2007());
 	}
@@ -32,22 +32,18 @@ public async Task NonTestMethod() {
 	[InlineData("TheoryAttribute")]
 	public async Task StandardTestMethod_Suppresses(string attribute)
 	{
-		var code = @$"
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {{
-    [{attribute}]
-    public async Task TestMethod() {{
-        await Task.Delay(1);
-    }}
-}}";
-
-		// Roslyn 3.11 still surfaces the diagnostic that has been suppressed
-		var expected =
-			new DiagnosticResult("CA2007", DiagnosticSeverity.Warning)
-				.WithSpan(8, 15, 8, 28)
-				.WithIsSuppressed(true);
+		var code = string.Format(/* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {{
+			    [{0}]
+			    public async Task TestMethod() {{
+			        await {{|#0:Task.Delay(1)|}};
+			    }}
+			}}
+			""", attribute);
+		var expected = DiagnosticResult.CompilerWarning("CA2007").WithLocation(0).WithIsSuppressed(true);
 
 		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA2007(), expected);
 	}
@@ -55,18 +51,19 @@ public async Task TestMethod() {{
 	[Fact]
 	public async Task CustomFactTestMethod_DoesNotSuppress()
 	{
-		var code = @"
-using System.Threading.Tasks;
-using Xunit;
+		var code = /* lang=c#-test */ """
+			using System.Threading.Tasks;
+			using Xunit;
 
-internal class CustomFactAttribute : FactAttribute { }
+			internal class CustomFactAttribute : FactAttribute { }
 
-public class TestClass {
-    [CustomFact]
-    public async Task TestMethod() {
-        await {|CA2007:Task.Delay(1)|};
-    }
-}";
+			public class TestClass {
+			    [CustomFact]
+			    public async Task TestMethod() {
+			        await {|CA2007:Task.Delay(1)|};
+			    }
+			}
+			""";
 
 		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA2007());
 	}
@@ -74,19 +71,20 @@ public async Task TestMethod() {
 	[Fact]
 	public async Task CodeInsideFunctions_DoesNotSuppress()
 	{
-		var code = @"
-using System;
-using System.Threading.Tasks;
-using Xunit;
-
-public class TestClass {
-    [Fact]
-    public void TestMethod() {
-        async Task InnerMethod1() { await {|CA2007:Task.Delay(1)|}; }
-        async Task InnerMethod2() => await {|CA2007:Task.Delay(1)|};
-        Func<Task> Lambda = async () => await {|CA2007:Task.Delay(1)|};
-    }
-}";
+		var code = /* lang=c#-test */ """
+			using System;
+			using System.Threading.Tasks;
+			using Xunit;
+
+			public class TestClass {
+			    [Fact]
+			    public void TestMethod() {
+			        async Task InnerMethod1() { await {|CA2007:Task.Delay(1)|}; }
+			        async Task InnerMethod2() => await {|CA2007:Task.Delay(1)|};
+			        Func<Task> Lambda = async () => await {|CA2007:Task.Delay(1)|};
+			    }
+			}
+			""";
 
 		await Verify.VerifySuppressor(LanguageVersion.CSharp7, code, CodeAnalysisNetAnalyzers.CA2007());
 	}
diff --git a/src/xunit.analyzers.tests/Suppressors/MakeTypesInternalSuppressorTests.cs b/src/xunit.analyzers.tests/Suppressors/MakeTypesInternalSuppressorTests.cs
index 92514ea4..7bf207d5 100644
--- a/src/xunit.analyzers.tests/Suppressors/MakeTypesInternalSuppressorTests.cs
+++ b/src/xunit.analyzers.tests/Suppressors/MakeTypesInternalSuppressorTests.cs
@@ -12,17 +12,13 @@ public sealed class MakeTypesInternalSuppressorTests
 	[Fact]
 	public async Task NonTestClass_DoesNotSuppress()
 	{
-		var code = @"
-public class NonTestClass {
-    public void NonTestMethod() { }
-}";
+		var code = /* lang=c#-test */ """
+			public class {|CA1515:NonTestClass|} {
+			    public void NonTestMethod() { }
+			}
+			""";
 
-		var expected =
-			new DiagnosticResult("CA1515", DiagnosticSeverity.Warning)
-				.WithSpan(2, 14, 2, 26)
-				.WithIsSuppressed(false);
-
-		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA1515(), expected);
+		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA1515());
 	}
 
 	[Theory]
@@ -34,21 +30,17 @@ public void NonTestMethod() { }
 	[InlineData("CustomFactAttribute")]
 	public async Task TestClass_Suppresses(string attribute)
 	{
-		var code = @$"
-using Xunit;
-
-internal class CustomFactAttribute : FactAttribute {{ }}
+		var code = string.Format(/* lang=c#-test */ """
+			using Xunit;
 
-public class TestClass {{
-    [{attribute}]
-    public void TestMethod() {{ }}
-}}";
+			internal class CustomFactAttribute : FactAttribute {{ }}
 
-		// Roslyn 3.11 still surfaces the diagnostic that has been suppressed
-		var expected =
-			new DiagnosticResult("CA1515", DiagnosticSeverity.Warning)
-				.WithSpan(6, 14, 6, 23)
-				.WithIsSuppressed(true);
+			public class {{|#0:TestClass|}} {{
+			    [{0}]
+			    public void TestMethod() {{ }}
+			}}
+			""", attribute);
+		var expected = new DiagnosticResult("CA1515", DiagnosticSeverity.Warning).WithLocation(0).WithIsSuppressed(true);
 
 		await Verify.VerifySuppressor(code, CodeAnalysisNetAnalyzers.CA1515(), expected);
 	}
diff --git a/src/xunit.analyzers.tests/Utility/CodeAnalyzerHelper.cs b/src/xunit.analyzers.tests/Utility/CodeAnalyzerHelper.cs
index a2a6328c..de066b80 100644
--- a/src/xunit.analyzers.tests/Utility/CodeAnalyzerHelper.cs
+++ b/src/xunit.analyzers.tests/Utility/CodeAnalyzerHelper.cs
@@ -39,8 +39,8 @@ static CodeAnalyzerHelper()
 				new PackageIdentity("System.Collections.Immutable", "1.6.0"),
 				new PackageIdentity("System.Threading.Tasks.Extensions", "4.5.4"),
 				new PackageIdentity("xunit.abstractions", "2.0.3"),
-				new PackageIdentity("xunit.assert", "2.8.2-pre.19"),
-				new PackageIdentity("xunit.core", "2.8.2-pre.19")
+				new PackageIdentity("xunit.assert", "2.9.1-pre.5"),
+				new PackageIdentity("xunit.core", "2.9.1-pre.5")
 			)
 		);
 
@@ -51,7 +51,7 @@ static CodeAnalyzerHelper()
 				new PackageIdentity("System.Collections.Immutable", "1.6.0"),
 				new PackageIdentity("System.Threading.Tasks.Extensions", "4.5.4"),
 				new PackageIdentity("xunit.abstractions", "2.0.3"),
-				new PackageIdentity("xunit.runner.utility", "2.8.2-pre.19")
+				new PackageIdentity("xunit.runner.utility", "2.9.1-pre.5")
 			)
 		);
 
diff --git a/src/xunit.analyzers.tests/xunit.analyzers.tests.csproj b/src/xunit.analyzers.tests/xunit.analyzers.tests.csproj
index 888f4179..ac19a533 100644
--- a/src/xunit.analyzers.tests/xunit.analyzers.tests.csproj
+++ b/src/xunit.analyzers.tests/xunit.analyzers.tests.csproj
@@ -12,8 +12,8 @@
     <PackageDownload Include="System.Collections.Immutable" Version="[1.6.0]" Condition=" '$(TargetFramework)' == 'net472' " />
     <PackageDownload Include="System.Text.Json" Version="[8.0.0]" />
     <PackageDownload Include="System.Threading.Tasks.Extensions" Version="[4.5.4]" />
-    <PackageDownload Include="xunit.assert" Version="[2.8.2-pre.19]" />
-    <PackageDownload Include="xunit.runner.utility" Version="[2.8.2-pre.19]" />
+    <PackageDownload Include="xunit.assert" Version="[2.9.1-pre.5]" />
+    <PackageDownload Include="xunit.runner.utility" Version="[2.9.1-pre.5]" />
     <PackageDownload Include="xunit.v3.assert" Version="[0.2.0-pre.4]" />
     <PackageDownload Include="xunit.v3.common" Version="[0.2.0-pre.4]" />
     <PackageDownload Include="xunit.v3.extensibility.core" Version="[0.2.0-pre.4]" />
diff --git a/src/xunit.analyzers/X1000/PublicMethodShouldBeMarkedAsTest.cs b/src/xunit.analyzers/X1000/PublicMethodShouldBeMarkedAsTest.cs
index c5baa6f9..b021d756 100644
--- a/src/xunit.analyzers/X1000/PublicMethodShouldBeMarkedAsTest.cs
+++ b/src/xunit.analyzers/X1000/PublicMethodShouldBeMarkedAsTest.cs
@@ -84,7 +84,7 @@ public override void AnalyzeCompilation(
 					var shouldIgnore = false;
 					while (!shouldIgnore || method.IsOverride)
 					{
-						if (methodsToIgnore.Any(m => SymbolEqualityComparer.Default.Equals(method, m)))
+						if (methodsToIgnore.Any(m => SymbolEqualityComparer.Default.Equals(method, m)) || !method.ReceiverType.IsTestClass(xunitContext, strict: true))
 							shouldIgnore = true;
 
 						if (!method.IsOverride)
diff --git a/tools/builder/common b/tools/builder/common
index 90dba1f5..1faa6934 160000
--- a/tools/builder/common
+++ b/tools/builder/common
@@ -1 +1 @@
-Subproject commit 90dba1f5638a4f00d4978a73e23edde5b85061d9
+Subproject commit 1faa6934a6c163aa377b1bcc96ff65cbc3a9eac4