Make MediaType sealed and adjust Eclipse setup

gradle/plugins/common/src/main/kotlin/junitbuild.eclipse-conventions.gradle.kts

@@ -0,0 +1,52 @@
+import junitbuild.eclipse.EclipseConventionsExtension
+import org.gradle.plugins.ide.eclipse.model.Classpath
+import org.gradle.plugins.ide.eclipse.model.Library
+import org.gradle.plugins.ide.eclipse.model.ProjectDependency
+import org.gradle.plugins.ide.eclipse.model.SourceFolder
+
+plugins {
+	eclipse
+}
+
+val extension = extensions.create<EclipseConventionsExtension>("eclipseConventions").apply {
+	hideModularity.convention(true)
+}
+
+eclipse {
+	jdt {
+		sourceCompatibility = JavaVersion.VERSION_21
+		targetCompatibility = JavaVersion.VERSION_21
+		file {
+			// Set properties for org.eclipse.jdt.core.prefs
+			withProperties {
+				// Configure Eclipse projects with -release compiler flag.
+				setProperty("org.eclipse.jdt.core.compiler.release", "enabled")
+				// Configure Eclipse projects with -parameters compiler flag.
+				setProperty("org.eclipse.jdt.core.compiler.codegen.methodParameters", "generate")
+			}
+		}
+	}
+	classpath.file.whenMerged {
+		this as Classpath
+		// Remove classpath entries for non-existent libraries added by various
+		// plugins, such as "junit-jupiter-api/build/classes/kotlin/testFixtures".
+		entries.removeIf { it is Library && !file(it.path).exists() }
+		// Remove classpath entries for the code generator model used by the
+		// Java Template Engine (JTE) which is used to generate the JRE enum and
+		// dependent tests.
+		entries.removeIf { it is ProjectDependency && it.path.equals("/code-generator-model") }
+		// Remove classpath entries for anything used by the Gradle Wrapper.
+		entries.removeIf { it is Library && it.path.contains("gradle/wrapper") }
+		if (extension.hideModularity.get()) {
+			entries.filterIsInstance<SourceFolder>().forEach {
+				it.excludes.add("**/module-info.java")
+			}
+			entries.filterIsInstance<ProjectDependency>().forEach {
+				it.entryAttributes.remove("module")
+			}
+			entries.filterIsInstance<Library>().forEach {
+				it.entryAttributes.remove("module")
+			}
+		}
+	}
+}

gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts

@@ -1,16 +1,12 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import junitbuild.extensions.isSnapshot
-import org.gradle.plugins.ide.eclipse.model.Classpath
-import org.gradle.plugins.ide.eclipse.model.Library
-import org.gradle.plugins.ide.eclipse.model.ProjectDependency
-import org.gradle.plugins.ide.eclipse.model.SourceFolder
 
 plugins {
 	`java-library`
-	eclipse
 	id("junitbuild.base-conventions")
 	id("junitbuild.build-parameters")
 	id("junitbuild.checkstyle-conventions")
+	id("junitbuild.eclipse-conventions")
 	id("junitbuild.jacoco-java-conventions")
 }
 
@@ -21,43 +17,6 @@ val buildRevision: Any by rootProject.extra
 
 val extension = extensions.create<JavaLibraryExtension>("javaLibrary")
 
-eclipse {
-	jdt {
-		sourceCompatibility = JavaVersion.VERSION_21
-		targetCompatibility = JavaVersion.VERSION_21
-		file {
-			// Set properties for org.eclipse.jdt.core.prefs
-			withProperties {
-				// Configure Eclipse projects with -release compiler flag.
-				setProperty("org.eclipse.jdt.core.compiler.release", "enabled")
-				// Configure Eclipse projects with -parameters compiler flag.
-				setProperty("org.eclipse.jdt.core.compiler.codegen.methodParameters", "generate")
-			}
-		}
-	}
-	classpath.file.whenMerged {
-		this as Classpath
-		// Remove classpath entries for non-existent libraries added by various
-		// plugins, such as "junit-jupiter-api/build/classes/kotlin/testFixtures".
-		entries.removeIf { it is Library && !file(it.path).exists() }
-		// Remove classpath entries for the code generator model used by the
-		// Java Template Engine (JTE) which is used to generate the JRE enum and
-		// dependent tests.
-		entries.removeIf { it is ProjectDependency && it.path.equals("/code-generator-model") }
-		// Remove classpath entries for anything used by the Gradle Wrapper.
-		entries.removeIf { it is Library && it.path.contains("gradle/wrapper") }
-		entries.filterIsInstance<SourceFolder>().forEach {
-			it.excludes.add("**/module-info.java")
-		}
-		entries.filterIsInstance<ProjectDependency>().forEach {
-			it.entryAttributes.remove("module")
-		}
-		entries.filterIsInstance<Library>().forEach {
-			it.entryAttributes.remove("module")
-		}
-	}
-}
-
 java {
 	modularity.inferModulePath = true
 }

gradle/plugins/common/src/main/kotlin/junitbuild/eclipse/EclipseConventionsExtension.kt

@@ -0,0 +1,7 @@
+package junitbuild.eclipse
+
+import org.gradle.api.provider.Property
+
+abstract class EclipseConventionsExtension {
+    abstract val hideModularity: Property<Boolean>
+}

junit-jupiter-api/junit-jupiter-api.gradle.kts

@@ -28,6 +28,10 @@ javadocConventions {
 	addExtraModuleReferences(projects.junitPlatformEngine, projects.junitPlatformLauncher, projects.junitJupiterParams)
 }
 
+eclipseConventions {
+	hideModularity = false
+}
+
 tasks {
 	compileJava {
 		options.compilerArgs.add("-Xlint:-module") // due to qualified exports

junit-jupiter-api/src/main/java/org/junit/jupiter/api/MediaType.java

@@ -34,8 +34,9 @@
  * @see TestReporter#publishFile(String, MediaType, org.junit.jupiter.api.function.ThrowingConsumer)
  * @see org.junit.jupiter.api.extension.ExtensionContext#publishFile(String, MediaType, org.junit.jupiter.api.function.ThrowingConsumer)
  */
+@SuppressWarnings("removal")
 @API(status = MAINTAINED, since = "5.14")
-public class MediaType {
+public sealed class MediaType permits org.junit.jupiter.api.extension.MediaType {
 
 	private static final Pattern PATTERN;
 
@@ -125,13 +126,6 @@ protected MediaType(String type, String subtype, @Nullable Charset charset) {
 	}
 
 	protected MediaType(String value) {
-		// Mimic sealed types, permitting only this class and api.extension.MediaType.
-		if (getClass() != MediaType.class
-				&& !getClass().getName().equals("org.junit.jupiter.api.extension.MediaType")) {
-			throw new IllegalStateException(
-				"Type '%s' is not permitted to extend MediaType".formatted(getClass().getName()));
-		}
-
 		String strippedValue = Preconditions.notBlank(value, "value must not be null or blank").strip();
 		Matcher matcher = PATTERN.matcher(strippedValue);
 		Preconditions.condition(matcher.matches(), () -> "Invalid media type: '" + strippedValue + "'");

junit-jupiter-api/src/testFixtures/java/org/junit/jupiter/api/fixtures/TrackLogRecords.java

@@ -15,7 +15,6 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
-import org.jspecify.annotations.NullMarked;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -42,7 +41,6 @@
  * @see LoggerFactory
  * @see LogRecordListener
  */
-@NullMarked
 @Target({ ElementType.TYPE, ElementType.PARAMETER })
 @Retention(RetentionPolicy.RUNTIME)
 @ExtendWith(TrackLogRecords.Extension.class)

junit-platform-commons/junit-platform-commons.gradle.kts

@@ -25,6 +25,10 @@ javadocConventions {
 	addExtraModuleReferences(projects.junitPlatformEngine)
 }
 
+eclipseConventions {
+	hideModularity = false
+}
+
 tasks.compileJava {
 	options.compilerArgs.add("-Xlint:-module") // due to qualified exports
 	val moduleName = javaModuleName

jupiter-tests/src/test/java/org/junit/jupiter/api/MediaTypeTests.java

@@ -12,14 +12,11 @@
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.junit.jupiter.api.EqualsAndHashCodeAssertions.assertEqualsAndHashCode;
 import static org.junit.platform.commons.test.PreconditionAssertions.assertPreconditionViolationFor;
 import static org.junit.platform.commons.test.PreconditionAssertions.assertPreconditionViolationNotNullFor;
 import static org.junit.platform.commons.test.PreconditionAssertions.assertPreconditionViolationNotNullOrBlankFor;
 
-import java.nio.charset.Charset;
-
 import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.NullAndEmptySource;
@@ -33,31 +30,6 @@
  */
 class MediaTypeTests {
 
-	@Test
-	void pseudoSealedType() {
-
-		class CustomMediaType extends MediaType {
-
-			CustomMediaType(String value) {
-				super(value);
-			}
-
-			CustomMediaType(String type, String subtype, @Nullable Charset charset) {
-				super(type, subtype, charset);
-			}
-		}
-
-		String message = "Type '%s' is not permitted to extend MediaType".formatted(CustomMediaType.class.getName());
-
-		assertThatIllegalStateException()//
-				.isThrownBy(() -> new CustomMediaType("text/plain"))//
-				.withMessage(message);
-
-		assertThatIllegalStateException()//
-				.isThrownBy(() -> new CustomMediaType("text", "plain", UTF_8))//
-				.withMessage(message);
-	}
-
 	@Test
 	void equals() {
 		var mediaType1 = MediaType.TEXT_PLAIN;