Add support for JUnit 'vintage' attribute on classpath

JDT supports a new classpath attribute on the JUnit5 container that
disables the vintage engine. This is especially important if one wants
to write plain JUnit5 test as it is otherwise easy to mix up Junit4/5.

This now adds a testcase that shows that such mixed usage would fail
compilation.

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/.classpath

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="src" output="test" path="src_test">
+		<attributes>
+			<attribute name="test" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" path="src2"/>
+	<classpathentry kind="src" output="test" path="integration-tests">
+		<attributes>
+			<attribute name="test" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-11">
+		<attributes>
+			<attribute name="module" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/5">
+		<attributes>
+			<attribute name="vintage" value="false" />
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/META-INF/MANIFEST.MF

@@ -0,0 +1,9 @@
+Manifest-Version: 1.0
+Bundle-ManifestVersion: 2
+Bundle-Name: Test Plug-in
+Bundle-SymbolicName: bundle.test5
+Bundle-Version: 1.0.0
+Import-Package: javax.annotation,
+ org.osgi.framework
+Automatic-Module-Name: bundle.test5
+Bundle-RequiredExecutionEnvironment: JavaSE-11

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/build.properties

@@ -0,0 +1,4 @@
+source.. = src/,src2/
+output.. = bin/
+bin.includes = META-INF/,\
+               .

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/pom.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project>
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.eclipse.tycho.tycho-its.surefire</groupId>
+	<artifactId>bundle.test5</artifactId>
+	<packaging>eclipse-plugin</packaging>
+	<version>1.0.0</version>
+	<properties>
+		<target-platform>https:////download.eclipse.org/releases/2022-12/</target-platform>
+		<tycho-version>4.0.0-SNAPSHOT</tycho-version>
+	</properties>
+	<repositories>
+		<repository>
+			<id>platform</id>
+			<url>${target-platform}</url>
+			<layout>p2</layout>
+		</repository>
+	</repositories>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.eclipse.tycho</groupId>
+				<artifactId>tycho-maven-plugin</artifactId>
+				<version>${tycho-version}</version>
+				<extensions>true</extensions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>3.0.0-M5</version>
+				<dependencies>
+					<dependency>
+						<groupId>org.apache.maven.surefire</groupId>
+						<artifactId>surefire-junit47</artifactId>
+						<version>3.0.0-M5</version>
+					</dependency>
+				</dependencies>
+				<executions>
+					<execution>
+						<id>execute-tests</id>
+						<goals>
+							<goal>test</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/src/bundle/test/CountDown.java

@@ -0,0 +1,38 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Christoph Läubrich. - initial API and implementation
+ *******************************************************************************/
+package bundle.test;
+
+public class CountDown {
+
+	RefMe refFromOtherSourceFolder;
+
+	int count;
+
+	public CountDown(int initalValue) {
+		count = initalValue;
+	}
+
+	public void decrement(int x) {
+		if (x < 0) {
+			throw new IllegalArgumentException();
+		}
+		if (count-x < 0) {
+			throw new IllegalStateException();
+		}
+		count -= x;
+	}
+
+	public int get() {
+		return count;
+	}
+}

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/src/bundle/test/Counter.java

@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Christoph Läubrich. - initial API and implementation
+ *******************************************************************************/
+package bundle.test;
+
+public class Counter {
+
+	int count;
+
+	public void increment(int x) {
+		if (x < 0) {
+			throw new IllegalArgumentException();
+		}
+		count += x;
+	}
+
+	public int get() {
+		return count;
+	}
+}

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/src2/bundle/test/RefMe.java

@@ -0,0 +1,18 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Christoph Läubrich. - initial API and implementation
+ *******************************************************************************/
+
+package bundle.test;
+
+public class RefMe extends Counter{
+
+}

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/src_test/bundle/test/AdderTest.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Christoph Läubrich. - initial API and implementation
+ *******************************************************************************/
+package bundle.test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class AdderTest {
+
+    @org.junit.jupiter.api.Test
+	public void incrementTest() {
+		Counter counter = new Counter();
+		counter.increment(1);
+		counter.increment(3);
+		assertEquals(4, counter.get());
+    }
+
+    @org.junit.jupiter.api.Test
+	public void decrementTest() {
+		assertThrows(IllegalArgumentException.class, ()->{
+			Counter counter = new Counter();
+			counter.increment(-1);
+		});
+	}
+}

tycho-its/projects/surefire.combinedtests/bundle5.no.vintage.test/src_test/bundle/test/SubtractorTest.java

@@ -0,0 +1,40 @@
+/*******************************************************************************
+ * Copyright (c) 2021 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Christoph Läubrich  - initial API and implementation
+ *******************************************************************************/
+package bundle.test;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class SubtractorTest {
+
+	@Test
+	public void incrementTest() {
+		CountDown counter = new CountDown(10);
+		counter.decrement(1);
+		counter.decrement(3);
+		assertEquals(6, counter.get());
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void decrementTest() {
+		CountDown counter = new CountDown(10);
+		counter.decrement(-1);
+	}
+
+	@Test(expected = IllegalStateException.class)
+	public void decrementTest2() {
+		CountDown counter = new CountDown(1);
+		counter.decrement(5);
+	}
+}

tycho-its/src/test/java/org/eclipse/tycho/test/surefire/TestsInBundleTest.java

@@ -47,6 +47,15 @@ public void testCompile5() throws Exception {
 				new File(verifier.getBasedir(), "target/test-classes/bundle/test/AdderTest.class").exists());
 	}
 
+	@Test
+	public void testCompile5WithoutVintage() throws Exception {
+		Verifier verifier = getVerifier("surefire.combinedtests/bundle5.no.vintage.test");
+		assertThrows("Compilation must fail because the usage of junit 4 annotations", VerificationException.class,
+				() -> verifier.executeGoals(Arrays.asList("clean", "test-compile")));
+		verifier.verifyTextInLog("The import org.junit.Assert cannot be resolved");
+		verifier.verifyTextInLog("The import org.junit.Test cannot be resolved");
+	}
+
 	@Test
 	public void testTest() throws Exception {
 		Verifier verifier = getVerifier("surefire.combinedtests/bundle.test");

tycho-metadata-model/src/main/java/org/eclipse/tycho/model/classpath/ClasspathParser.java

@@ -220,11 +220,24 @@ public Collection<JUnitBundle> getArtifacts() {
             } else if (JUNIT4.equals(junit)) {
                 return JUNIT4_PLUGINS;
             } else if (JUNIT5.equals(junit)) {
-                return JUNIT5_PLUGINS;
+                if (isVintage()) {
+                    return JUNIT5_PLUGINS;
+                } else {
+                    return JUNIT5_WITHOUT_VINTAGE_PLUGINS;
+                }
             }
             return Collections.emptyList();
         }
 
+        @Override
+        public boolean isVintage() {
+            String vintage = getAttributes().get("vintage");
+            if (vintage != null && !vintage.isBlank()) {
+                return Boolean.parseBoolean(vintage);
+            }
+            return true;
+        }
+
     }
 
     private static class JDTContainerClasspathEntry implements ClasspathContainerEntry {

tycho-metadata-model/src/main/java/org/eclipse/tycho/model/classpath/JUnitClasspathContainerEntry.java

@@ -76,6 +76,12 @@ public interface JUnitClasspathContainerEntry extends ClasspathContainerEntry {
             JUNIT_PLATFORM_SUITE_API_PLUGIN, JUNIT_VINTAGE_ENGINE_PLUGIN, JUNIT_OPENTEST4J_PLUGIN,
             JUNIT_APIGUARDIAN_PLUGIN, JUNIT4_PLUGIN, HAMCREST_CORE_PLUGIN);
 
+    static final List<JUnitBundle> JUNIT5_WITHOUT_VINTAGE_PLUGINS = List.of(JUNIT_JUPITER_API_PLUGIN,
+            JUNIT_JUPITER_ENGINE_PLUGIN, JUNIT_JUPITER_MIGRATIONSUPPORT_PLUGIN, JUNIT_JUPITER_PARAMS_PLUGIN,
+            JUNIT_PLATFORM_COMMONS_PLUGIN, JUNIT_PLATFORM_ENGINE_PLUGIN, JUNIT_PLATFORM_LAUNCHER_PLUGIN,
+            JUNIT_PLATFORM_RUNNER_PLUGIN, JUNIT_PLATFORM_SUITE_API_PLUGIN, JUNIT_OPENTEST4J_PLUGIN,
+            JUNIT_APIGUARDIAN_PLUGIN, HAMCREST_CORE_PLUGIN);
+
     /**
      * 
      * @return the JUnit part of the path
@@ -93,4 +99,12 @@ default boolean isTest() {
         return true;
     }
 
+    /**
+     * Checks if for JUnit5 the vintage engine has to be included. This is only meaningful if
+     * {@link #getJUnitSegment()} is equal to {@link #JUNIT5}
+     * 
+     * @return <code>true</code> if vintage is enabled (the default)
+     */
+    boolean isVintage();
+
 }