Remove testInstance parameter from TestInstancePostProcessor

Issue: #910

Author: sbrannen

junit-jupiter-api/src/main/java/org/junit/jupiter/api/extension/TestInstancePostProcessor.java

@@ -30,11 +30,12 @@
 public interface TestInstancePostProcessor extends Extension {
 
 	/**
-	 * Callback for post-processing the supplied test instance.
+	 * Callback for post-processing the test instance in the supplied
+	 * {@link ExtensionContext}.
 	 *
-	 * @param testInstance the instance to post-process; never {@code null}
 	 * @param context the current extension context; never {@code null}
+	 * @see ExtensionContext#getTestInstance()
 	 */
-	void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception;
+	void postProcessTestInstance(ExtensionContext context) throws Exception;
 
 }

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/ClassTestDescriptor.java

@@ -193,7 +193,7 @@ private Object instantiateAndPostProcessTestInstance(JupiterEngineExecutionConte
 
 		Object instance = instantiateTestClass(context, registry, extensionContext);
 		testInstanceConsumer.accept(instance);
-		invokeTestInstancePostProcessors(instance, registry, extensionContext);
+		invokeTestInstancePostProcessors(registry, extensionContext);
 		return instance;
 	}
 
@@ -204,11 +204,9 @@ protected Object instantiateTestClass(JupiterEngineExecutionContext parentExecut
 		return executableInvoker.invoke(constructor, extensionContext, registry);
 	}
 
-	private void invokeTestInstancePostProcessors(Object instance, ExtensionRegistry registry,
-			ExtensionContext context) {
-
+	private void invokeTestInstancePostProcessors(ExtensionRegistry registry, ExtensionContext context) {
 		registry.stream(TestInstancePostProcessor.class).forEach(
-			extension -> executeAndMaskThrowable(() -> extension.postProcessTestInstance(instance, context)));
+			extension -> executeAndMaskThrowable(() -> extension.postProcessTestInstance(context)));
 	}
 
 	private void invokeBeforeAllCallbacks(JupiterEngineExecutionContext context) {

junit-jupiter-engine/src/test/java/org/junit/jupiter/api/extension/KitchenSinkExtension.java

@@ -85,7 +85,7 @@ public void afterAll(ExtensionContext context) throws Exception {
 	// --- Dependency Injection ------------------------------------------------
 
 	@Override
-	public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+	public void postProcessTestInstance(ExtensionContext context) throws Exception {
 	}
 
 	@Override
@@ -118,7 +118,6 @@ public boolean supportsTestTemplate(ExtensionContext context) {
 
 	@Override
 	public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
-
 		return null;
 	}
 

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/TestInstanceLifecycleTests.java

@@ -877,9 +877,8 @@ public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext con
 		}
 
 		@Override
-		public void postProcessTestInstance(Object testInstance, ExtensionContext context) {
-			assertNotNull(testInstance);
-			context.getTestInstance().ifPresent(instance -> assertSame(testInstance, instance));
+		public void postProcessTestInstance(ExtensionContext context) {
+			Object testInstance = context.getTestInstance().orElse(null);
 			instanceMap.put(postProcessTestInstanceKey(context.getTestClass().get()), testInstance);
 		}
 

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/TestTemplateInvocationTests.java

@@ -508,9 +508,11 @@ public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContex
 
 	private static class SingleInvocationContextProviderWithDisabledInvocations
 			extends SingleInvocationContextProvider {
+
 		@Override
 		public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
 			return Stream.of(new TestTemplateInvocationContext() {
+
 				@Override
 				public List<Extension> getAdditionalExtensions() {
 					return singletonList(new AlwaysDisabledExecutionCondition());
@@ -645,7 +647,8 @@ public String getDisplayName(int invocationIndex) {
 
 				@Override
 				public List<Extension> getAdditionalExtensions() {
-					return singletonList((TestInstancePostProcessor) (testInstance, context) -> {
+					return singletonList((TestInstancePostProcessor) (context) -> {
+						Object testInstance = context.getTestInstance().orElse(null);
 						Field field = testInstance.getClass().getDeclaredField("parameterInstanceVariable");
 						field.setAccessible(true);
 						field.set(testInstance, argument);

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

@@ -159,7 +159,8 @@ void test() {
 	private static class FooInstancePostProcessor implements TestInstancePostProcessor {
 
 		@Override
-		public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+		public void postProcessTestInstance(ExtensionContext context) throws Exception {
+			Object testInstance = context.getTestInstance().orElse(null);
 			if (testInstance instanceof Named) {
 				((Named) testInstance).setName("foo");
 			}
@@ -170,7 +171,8 @@ public void postProcessTestInstance(Object testInstance, ExtensionContext contex
 	private static class BarInstancePostProcessor implements TestInstancePostProcessor {
 
 		@Override
-		public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+		public void postProcessTestInstance(ExtensionContext context) throws Exception {
+			Object testInstance = context.getTestInstance().orElse(null);
 			if (testInstance instanceof Named) {
 				((Named) testInstance).setName("bar");
 			}