Move getTestInstance() to ExtensionContext

Issue: #419

Author: sbrannen

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

@@ -111,6 +111,15 @@ public interface ExtensionContext {
 	 */
 	Optional<Class<?>> getTestClass();
 
+	/**
+	 * Get the test instance associated with the current test or container,
+	 * if available.
+	 *
+	 * @return an {@code Optional} containing the test instance; never
+	 * {@code null} but potentially empty
+	 */
+	Optional<Object> getTestInstance();
+
 	/**
 	 * Get the {@link Method} associated with the current test, if available.
 	 *

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

@@ -25,13 +25,6 @@
 @API(Experimental)
 public interface TestExtensionContext extends ExtensionContext {
 
-	/**
-	 * Get the test instance associated with this {@code TestExtensionContext}.
-	 *
-	 * @return the test instance; never {@code null}
-	 */
-	Object getTestInstance();
-
 	/**
 	 * Get the exception that was thrown during execution of the test associated
 	 * with this {@code TestExtensionContext}, if available.

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

@@ -43,6 +43,12 @@ public Optional<Class<?>> getTestClass() {
 		return Optional.of(getTestDescriptor().getTestClass());
 	}
 
+	@Override
+	public Optional<Object> getTestInstance() {
+		// TODO Determine how to access the test instance
+		return null;
+	}
+
 	@Override
 	public Optional<Method> getTestMethod() {
 		return Optional.empty();

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

@@ -282,7 +282,7 @@ private AfterEachMethodAdapter synthesizeAfterEachMethodAdapter(Method method) {
 	private void invokeMethodInTestExtensionContext(Method method, TestExtensionContext context,
 			ExtensionRegistry registry) {
 
-		Object instance = ReflectionUtils.getOuterInstance(context.getTestInstance(),
+		Object instance = ReflectionUtils.getOuterInstance(context.getTestInstance().get(),
 			method.getDeclaringClass()).orElseThrow(
 				() -> new JUnitException("Failed to find instance for method: " + method.toGenericString()));
 

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

@@ -42,8 +42,14 @@ public Optional<Class<?>> getTestClass() {
 		return Optional.empty();
 	}
 
+	@Override
+	public Optional<Object> getTestInstance() {
+		return Optional.empty();
+	}
+
 	@Override
 	public Optional<Method> getTestMethod() {
 		return Optional.empty();
 	}
+
 }

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

@@ -56,8 +56,8 @@ public Optional<Method> getTestMethod() {
 	}
 
 	@Override
-	public Object getTestInstance() {
-		return this.testInstance;
+	public Optional<Object> getTestInstance() {
+		return Optional.of(this.testInstance);
 	}
 
 	@Override

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

@@ -168,7 +168,7 @@ protected void invokeTestMethod(JupiterEngineExecutionContext context, DynamicTe
 		throwableCollector.execute(() -> {
 			try {
 				Method testMethod = getTestMethod();
-				Object instance = testExtensionContext.getTestInstance();
+				Object instance = testExtensionContext.getTestInstance().get();
 				executableInvoker.invoke(testMethod, instance, testExtensionContext, context.getExtensionRegistry());
 			}
 			catch (Throwable throwable) {

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

@@ -66,7 +66,7 @@ protected void invokeTestMethod(JupiterEngineExecutionContext context, DynamicTe
 		TestExtensionContext testExtensionContext = (TestExtensionContext) context.getExtensionContext();
 
 		context.getThrowableCollector().execute(() -> {
-			Object instance = testExtensionContext.getTestInstance();
+			Object instance = testExtensionContext.getTestInstance().get();
 			Object testFactoryMethodResult = executableInvoker.invoke(getTestMethod(), instance, testExtensionContext,
 				context.getExtensionRegistry());
 			TestSource source = getSource().orElseThrow(() -> new JUnitException("Test source must be present"));

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

@@ -43,6 +43,12 @@ public Optional<Class<?>> getTestClass() {
 		return Optional.of(getTestDescriptor().getTestClass());
 	}
 
+	@Override
+	public Optional<Object> getTestInstance() {
+		// TODO Determine how to access the test instance
+		return null;
+	}
+
 	@Override
 	public Optional<Method> getTestMethod() {
 		return Optional.of(getTestDescriptor().getTestMethod());

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

@@ -24,12 +24,17 @@
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.TestInstance.Lifecycle;
 import org.junit.platform.engine.test.event.ExecutionEventRecorder;
+import org.junit.platform.runner.JUnitPlatform;
+import org.junit.runner.RunWith;
 
 /**
  * Tests for {@link TestInstance @TestInstance} lifecycle support.
  *
  * @since 5.0
  */
+@RunWith(JUnitPlatform.class)
+public
+
 class TestInstanceLifecycleTests extends AbstractJupiterTestEngineTests {
 
 	private static int instanceCount;

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/descriptor/TestFactoryTestDescriptorTests.java

@@ -76,7 +76,7 @@ void streamsFromTestFactoriesShouldBeClosedWhenTheyThrow() {
 
 	private void prepareMockForTestInstanceWithCustomStream(Stream<?> stream) {
 		Stream<?> mockStream = stream.onClose(() -> isClosed = true);
-		when(testExtensionContext.getTestInstance()).thenReturn(new CustomStreamTestCase(mockStream));
+		when(testExtensionContext.getTestInstance()).thenReturn(Optional.of(new CustomStreamTestCase(mockStream)));
 	}
 
 	private static class CustomStreamTestCase {

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/execution/ExtensionContextTests.java

@@ -114,7 +114,7 @@ void fromMethodTestDescriptor() {
 			() -> assertThat(testExtensionContext.getTestClass()).contains(OuterClass.class), //
 			() -> assertThat(testExtensionContext.getDisplayName()).isEqualTo(methodTestDescriptor.getDisplayName()), //
 			() -> assertThat(testExtensionContext.getParent()).contains(classExtensionContext), //
-			() -> assertThat(testExtensionContext.getTestInstance()).isExactlyInstanceOf(OuterClass.class) //
+			() -> assertThat(testExtensionContext.getTestInstance().get()).isExactlyInstanceOf(OuterClass.class) //
 		);
 	}
 
@@ -187,8 +187,9 @@ private ClassTestDescriptor nestedClassDescriptor() {
 	private ClassTestDescriptor outerClassDescriptor(TestDescriptor child) {
 		ClassTestDescriptor classTestDescriptor = new ClassTestDescriptor(UniqueId.root("class", "OuterClass"),
 			OuterClass.class);
-		if (child != null)
+		if (child != null) {
 			classTestDescriptor.addChild(child);
+		}
 		return classTestDescriptor;
 	}
 

junit-jupiter-migrationsupport/src/main/java/org/junit/jupiter/migrationsupport/rules/AbstractTestRuleSupport.java

@@ -72,11 +72,12 @@ public void afterEach(TestExtensionContext context) throws Exception {
 	private void invokeAppropriateMethodOnRuleAnnotatedMembers(TestExtensionContext context,
 			Consumer<GenericBeforeAndAfterAdvice> methodCaller) {
 
-		List<T> members = findRuleAnnotatedMembers(context.getTestInstance());
+		Object testInstance = context.getTestInstance().get();
+		List<T> members = findRuleAnnotatedMembers(testInstance);
 
 		// @formatter:off
 		members.stream()
-				.map(member -> TestRuleAnnotatedMemberFactory.from(context.getTestInstance(), member))
+				.map(member -> TestRuleAnnotatedMemberFactory.from(testInstance, member))
 				.map(this.adapterGenerator)
 				.forEach(methodCaller::accept);
 		// @formatter:on

junit-jupiter-params/src/test/java/org/junit/jupiter/params/ParameterizedTestExtensionTests.java

@@ -129,6 +129,11 @@ public Optional<Class<?>> getTestClass() {
 				return null;
 			}
 
+			@Override
+			public java.util.Optional<Object> getTestInstance() {
+				return Optional.empty();
+			}
+
 			@Override
 			public void publishReportEntry(Map<String, String> map) {
 			}