feat: Add string mutators for LastIndexOf and IndexOf. (#3054)

Added string mutators.
stryker-mutator · Oct 18, 2024 · 3f6e3ad · 3f6e3ad
1 parent 34fc801
commit 3f6e3ad
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Showing 3 changed files with 7 additions and 1 deletion.
diff --git a/docs/mutations.md b/docs/mutations.md
@@ -173,6 +173,8 @@ Do you have a suggestion for a (new) mutator? Feel free to create an [issue](htt
 | `ElementAt()`          | `'\0'`               |
 | `ElementAtOrDefault()` | `'\0'`               |
 | `EndsWith()`           | `StartsWith()`       |
+| `IndexOf()`            | `LastIndexOf()`      |
+| `LastIndexOf()`        | `IndexOf()`          |
 | `PadLeft()`            | `PadRight()`         |
 | `PadRight()`           | `PadLeft()`          |
 | `StartsWith()`         | `EndsWith()`         |

diff --git a/src/Stryker.Core/Stryker.Core.UnitTest/Mutators/StringMethodMutatorTests.cs b/src/Stryker.Core/Stryker.Core.UnitTest/Mutators/StringMethodMutatorTests.cs
@@ -59,6 +59,8 @@ void TestMethod() {
         "String Method Mutation (Replace ToLowerInvariant() with ToUpperInvariant())")]
     [DataRow("testString.PadLeft(10)", "PadRight", "String Method Mutation (Replace PadLeft() with PadRight())")]
     [DataRow("testString.PadRight(10)", "PadLeft", "String Method Mutation (Replace PadRight() with PadLeft())")]
+    [DataRow("testString.LastIndexOf(c)", "IndexOf", "String Method Mutation (Replace LastIndexOf() with IndexOf())")]
+    [DataRow("testString.IndexOf(c)", "LastIndexOf", "String Method Mutation (Replace IndexOf() with LastIndexOf())")]
     public void ShouldMutateStringMethods(string expression, string mutatedMethod, string expectedDisplayName)
     {
         var (semanticModel, expressionSyntax) = CreateSemanticModelFromExpression(expression);

diff --git a/src/Stryker.Core/Stryker.Core/Mutators/StringMethodMutator.cs b/src/Stryker.Core/Stryker.Core/Mutators/StringMethodMutator.cs
@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -63,6 +63,8 @@ private static string GetReplacement(string identifier) =>
             "ToLowerInvariant" => "ToUpperInvariant",
             "PadLeft" => "PadRight",
             "PadRight" => "PadLeft",
+            "IndexOf" => "LastIndexOf",
+            "LastIndexOf" => "IndexOf",
             _ => null
         };