Polish TestClassLoader usage

Author: sbrannen

junit-jupiter-engine/src/test/java/org/junit/jupiter/api/AssertThrowsAssertionsTests.java

@@ -241,9 +241,9 @@ void assertThrowsWithExecutableThatThrowsInstanceOfStaticNestedClassAsUnexpected
 	@Test
 	@SuppressWarnings("unchecked")
 	void assertThrowsWithExecutableThatThrowsSameExceptionTypeFromDifferentClassLoader() throws Exception {
-		try (TestClassLoader enigmaClassLoader = TestClassLoader.forClasses(EnigmaThrowable.class)) {
+		try (var testClassLoader = TestClassLoader.forClasses(EnigmaThrowable.class)) {
 			// Load expected exception type from different class loader
-			Class<? extends Throwable> enigmaThrowableClass = (Class<? extends Throwable>) enigmaClassLoader.loadClass(
+			Class<? extends Throwable> enigmaThrowableClass = (Class<? extends Throwable>) testClassLoader.loadClass(
 				EnigmaThrowable.class.getName());
 
 			try {

junit-jupiter-engine/src/test/java/org/junit/jupiter/api/AssertThrowsExactlyAssertionsTests.java

@@ -281,9 +281,9 @@ void assertThrowsWithExecutableThatThrowsInstanceOfStaticNestedClassAsUnexpected
 	@Test
 	@SuppressWarnings("unchecked")
 	void assertThrowsWithExecutableThatThrowsSameExceptionTypeFromDifferentClassLoader() throws Exception {
-		try (TestClassLoader enigmaClassLoader = TestClassLoader.forClasses(EnigmaThrowable.class)) {
+		try (var testClassLoader = TestClassLoader.forClasses(EnigmaThrowable.class)) {
 			// Load expected exception type from different class loader
-			Class<? extends Throwable> enigmaThrowableClass = (Class<? extends Throwable>) enigmaClassLoader.loadClass(
+			Class<? extends Throwable> enigmaThrowableClass = (Class<? extends Throwable>) testClassLoader.loadClass(
 				EnigmaThrowable.class.getName());
 
 			try {

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/extension/TestInstanceFactoryTests.java

@@ -692,13 +692,12 @@ private static class ProxyTestInstanceFactory implements TestInstanceFactory {
 		public Object createTestInstance(TestInstanceFactoryContext factoryContext, ExtensionContext extensionContext) {
 			Class<?> testClass = factoryContext.getTestClass();
 			String className = testClass.getName();
-			String prefix = TestInstanceFactoryTests.class.getName();
 
 			instantiated(getClass(), testClass);
 
-			try (TestClassLoader proxyClassLoader = TestClassLoader.forClassNamePrefix(prefix)) {
+			try (var testClassLoader = TestClassLoader.forClasses(testClass)) {
 				// Load test class from different class loader
-				Class<?> clazz = proxyClassLoader.loadClass(className);
+				Class<?> clazz = testClassLoader.loadClass(className);
 				return ReflectionUtils.newInstance(clazz);
 			}
 			catch (Exception ex) {

junit-jupiter-params/src/test/java/org/junit/jupiter/params/converter/DefaultArgumentConverterTests.java

@@ -211,17 +211,17 @@ void convertsStringToClass() {
 	@Test
 	void convertsStringToClassWithCustomTypeFromDifferentClassLoader() throws Exception {
 		String customTypeName = Enigma.class.getName();
-		try (TestClassLoader customTypeClassLoader = TestClassLoader.forClasses(Enigma.class)) {
-			var customType = customTypeClassLoader.loadClass(customTypeName);
-			assertThat(customType.getClassLoader()).isInstanceOf(TestClassLoader.class);
+		try (var testClassLoader = TestClassLoader.forClasses(Enigma.class)) {
+			var customType = testClassLoader.loadClass(customTypeName);
+			assertThat(customType.getClassLoader()).isSameAs(testClassLoader);
 
 			var declaringExecutable = ReflectionUtils.findMethod(customType, "foo").get();
-			assertThat(declaringExecutable.getDeclaringClass().getClassLoader()).isInstanceOf(TestClassLoader.class);
+			assertThat(declaringExecutable.getDeclaringClass().getClassLoader()).isSameAs(testClassLoader);
 
 			var clazz = (Class<?>) convert(customTypeName, Class.class, parameterContext(declaringExecutable));
 			assertThat(clazz).isNotEqualTo(Enigma.class);
 			assertThat(clazz).isEqualTo(customType);
-			assertThat(clazz.getClassLoader()).isInstanceOf(TestClassLoader.class);
+			assertThat(clazz.getClassLoader()).isSameAs(testClassLoader);
 		}
 	}
 

platform-tests/src/test/java/org/junit/platform/commons/util/ReflectionUtilsTests.java

@@ -1034,24 +1034,24 @@ void findMethodByParameterNamesWithWithCustomTypeFromDifferentClassLoader() thro
 		var customTypeName = CustomType.class.getName();
 		var nestedTypeName = CustomType.NestedType.class.getName();
 
-		try (TestClassLoader customTypeClassLoader = TestClassLoader.forClassNamePrefix(customTypeName)) {
-			var customType = customTypeClassLoader.loadClass(customTypeName);
-			assertThat(customType.getClassLoader()).isEqualTo(customTypeClassLoader);
+		try (var testClassLoader = TestClassLoader.forClassNamePrefix(customTypeName)) {
+			var customType = testClassLoader.loadClass(customTypeName);
+			assertThat(customType.getClassLoader()).isSameAs(testClassLoader);
 
 			var optional = findMethod(customType, methodName, nestedTypeName);
 			assertThat(optional).get().satisfies(method -> {
 				assertThat(method.getName()).isEqualTo(methodName);
 
 				var declaringClass = method.getDeclaringClass();
-				assertThat(declaringClass.getClassLoader()).isEqualTo(customTypeClassLoader);
+				assertThat(declaringClass.getClassLoader()).isSameAs(testClassLoader);
 				assertThat(declaringClass.getName()).isEqualTo(customTypeName);
 				assertThat(declaringClass).isNotEqualTo(CustomType.class);
 
 				var parameterTypes = method.getParameterTypes();
 				assertThat(parameterTypes).extracting(Class::getName).containsExactly(nestedTypeName);
 				Class<?> parameterType = parameterTypes[0];
 				assertThat(parameterType).isNotEqualTo(CustomType.NestedType.class);
-				assertThat(parameterType.getClassLoader()).isEqualTo(customTypeClassLoader);
+				assertThat(parameterType.getClassLoader()).isSameAs(testClassLoader);
 			});
 		}
 	}