Introduce getTest[Class|Method]() in TestInfo & ExtensionContext

This commit introduces Optional<Class<?>> getTestClass() and
Optional<Method> getTestMethod() methods in TestInfo and
ExtensionContext.

The existing `Class<?> getTestClass()` method in ExtensionContext has
simply been replaced, and the existing `Method getTestMethod()` method
in TestExtensionContext has been removed.

Issue: #153

documentation/src/test/java/example/timing/TimingExtension.java

@@ -31,12 +31,12 @@ public class TimingExtension implements BeforeTestMethodCallback, AfterTestMetho
 
 	@Override
 	public void beforeTestMethod(TestExtensionContext context) throws Exception {
-		getStore(context).put(context.getTestMethod(), System.currentTimeMillis());
+		getStore(context).put(context.getTestMethod().get(), System.currentTimeMillis());
 	}
 
 	@Override
 	public void afterTestMethod(TestExtensionContext context) throws Exception {
-		Method testMethod = context.getTestMethod();
+		Method testMethod = context.getTestMethod().get();
 		long start = (long) getStore(context).remove(testMethod);
 		long duration = System.currentTimeMillis() - start;
 

junit-tests/src/test/java/org/junit/gen5/engine/junit5/FullLogging.java

@@ -53,20 +53,22 @@ class Extension implements BeforeAllCallback, AfterAllCallback {
 
 		@Override
 		public void beforeAll(ContainerExtensionContext context) throws Exception {
-		// @formatter:off
-		Class<?>[] loggerClasses = findAnnotation(context.getTestClass(), FullLogging.class)
-				.orElseThrow(() -> new PreconditionViolationException("@FullLogging must be declared on class " +
-						context.getTestClass().getName()))
-				.value();
+			Class<?> testClass = context.getTestClass().get();
 
-		Arrays.stream(loggerClasses)
-				.map(Class::getName)
-				.forEach(loggerName -> {
-					Logger logger = Logger.getLogger(loggerName);
-					previouslyActiveLogLevels.put(loggerName, logger.getLevel());
-					logger.setLevel(Level.ALL);
-				});
-		// @formatter:on
+			// @formatter:off
+			Class<?>[] loggerClasses = findAnnotation(testClass, FullLogging.class)
+					.orElseThrow(() -> new PreconditionViolationException("@FullLogging must be declared on class " +
+							testClass.getName()))
+					.value();
+
+			Arrays.stream(loggerClasses)
+					.map(Class::getName)
+					.forEach(loggerName -> {
+						Logger logger = Logger.getLogger(loggerName);
+						previouslyActiveLogLevels.put(loggerName, logger.getLevel());
+						logger.setLevel(Level.ALL);
+					});
+			// @formatter:on
 		}
 
 		@Override

junit-tests/src/test/java/org/junit/gen5/engine/junit5/execution/ExtensionContextTests.java

@@ -38,6 +38,7 @@
  * Microtests for implementors of {@linkplain ExtensionContext}:
  * {@linkplain ClassBasedContainerExtensionContext} and
  * {@linkplain MethodBasedTestExtensionContext}
+ *
  * @since 5.0
  */
 public class ExtensionContextTests {
@@ -50,7 +51,7 @@ public void fromClassTestDescriptor() {
 		ClassBasedContainerExtensionContext outerExtensionContext = new ClassBasedContainerExtensionContext(null, null,
 			outerClassDescriptor);
 		Assertions.assertAll("outerContext", //
-			() -> assertEquals(OuterClass.class, outerExtensionContext.getTestClass()), //
+			() -> assertEquals(OuterClass.class, outerExtensionContext.getTestClass().get()), //
 			() -> assertEquals(outerClassDescriptor.getDisplayName(), outerExtensionContext.getDisplayName()), //
 			() -> assertEquals(Optional.empty(), outerExtensionContext.getParent()) //
 		);
@@ -87,7 +88,6 @@ public void tagsCanBeRetrievedInExtensionContext() {
 			() -> assertEquals(2, testExtensionContext.getTags().size()), //
 			() -> assertTrue(testExtensionContext.getTags().contains("outer-tag"), "outer-tag missing"), //
 			() -> assertTrue(testExtensionContext.getTags().contains("method-tag"), "method-tag missing"));
-
 	}
 
 	@Test
@@ -100,7 +100,7 @@ public void fromMethodTestDescriptor() {
 		MethodBasedTestExtensionContext testExtensionContext = new MethodBasedTestExtensionContext(
 			classExtensionContext, null, methodTestDescriptor, new OuterClass());
 		Assertions.assertAll("methodContext", //
-			() -> assertEquals(OuterClass.class, testExtensionContext.getTestClass()), //
+			() -> assertEquals(OuterClass.class, testExtensionContext.getTestClass().get()), //
 			() -> assertEquals(methodTestDescriptor.getDisplayName(), testExtensionContext.getDisplayName()), //
 			() -> assertEquals(classExtensionContext, testExtensionContext.getParent().get()), //
 			() -> assertEquals(OuterClass.class, testExtensionContext.getTestInstance().getClass()) //
@@ -188,12 +188,10 @@ static class OuterClass {
 
 		@Tag("nested-tag")
 		class NestedClass {
-
 		}
 
 		@Tag("method-tag")
 		void aMethod() {
-
 		}
 	}
 

junit5-api/src/main/java/org/junit/gen5/api/TestInfo.java

@@ -12,6 +12,8 @@
 
 import static org.junit.gen5.commons.meta.API.Usage.Experimental;
 
+import java.lang.reflect.Method;
+import java.util.Optional;
 import java.util.Set;
 
 import org.junit.gen5.commons.meta.API;
@@ -56,4 +58,15 @@ public interface TestInfo {
 	 * or "inherited" from an outer context.
 	 */
 	Set<String> getTags();
+
+	/**
+	 * Get the {@link Class} associated with the current test, if available.
+	 */
+	Optional<Class<?>> getTestClass();
+
+	/**
+	 * Get the {@link Method} associated with the current test, if available.
+	 */
+	Optional<Method> getTestMethod();
+
 }

junit5-api/src/main/java/org/junit/gen5/api/extension/ExtensionContext.java

@@ -13,6 +13,7 @@
 import static org.junit.gen5.commons.meta.API.Usage.Experimental;
 
 import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Map;
@@ -36,7 +37,7 @@
 public interface ExtensionContext {
 
 	/**
-	 * Get the parent extension context if there is one.
+	 * Get the parent extension context, if available.
 	 */
 	Optional<ExtensionContext> getParent();
 
@@ -71,9 +72,15 @@ public interface ExtensionContext {
 	Set<String> getTags();
 
 	/**
-	 * Get the {@link Class} associated with the current test or container.
+	 * Get the {@link Class} associated with the current test or container,
+	 * if available.
 	 */
-	Class<?> getTestClass();
+	Optional<Class<?>> getTestClass();
+
+	/**
+	 * Get the {@link Method} associated with the current test, if available.
+	 */
+	Optional<Method> getTestMethod();
 
 	/**
 	 * Get the {@link AnnotatedElement} corresponding to the current extension

junit5-api/src/main/java/org/junit/gen5/api/extension/TestExtensionContext.java

@@ -12,8 +12,6 @@
 
 import static org.junit.gen5.commons.meta.API.Usage.Experimental;
 
-import java.lang.reflect.Method;
-
 import org.junit.gen5.commons.meta.API;
 
 /**
@@ -27,5 +25,4 @@ public interface TestExtensionContext extends ExtensionContext {
 
 	Object getTestInstance();
 
-	Method getTestMethod();
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/ClassBasedContainerExtensionContext.java

@@ -13,6 +13,8 @@
 import static org.junit.gen5.commons.meta.API.Usage.Internal;
 
 import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+import java.util.Optional;
 
 import org.junit.gen5.api.extension.ContainerExtensionContext;
 import org.junit.gen5.api.extension.ExtensionContext;
@@ -48,12 +50,17 @@ public String getDisplayName() {
 
 	@Override
 	public AnnotatedElement getElement() {
-		return getTestClass();
+		return getTestClass().get();
 	}
 
 	@Override
-	public Class<?> getTestClass() {
-		return ((ClassTestDescriptor) getTestDescriptor()).getTestClass();
+	public Optional<Class<?>> getTestClass() {
+		return Optional.of(((ClassTestDescriptor) getTestDescriptor()).getTestClass());
+	}
+
+	@Override
+	public Optional<Method> getTestMethod() {
+		return Optional.empty();
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/MethodBasedTestExtensionContext.java

@@ -14,6 +14,7 @@
 
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
+import java.util.Optional;
 
 import org.junit.gen5.api.extension.ExtensionContext;
 import org.junit.gen5.api.extension.TestExtensionContext;
@@ -35,8 +36,8 @@ public MethodBasedTestExtensionContext(ExtensionContext parent, EngineExecutionL
 	}
 
 	@Override
-	public Method getTestMethod() {
-		return ((MethodTestDescriptor) getTestDescriptor()).getTestMethod();
+	public Optional<Method> getTestMethod() {
+		return Optional.of(((MethodTestDescriptor) getTestDescriptor()).getTestMethod());
 	}
 
 	@Override
@@ -45,8 +46,8 @@ public Object getTestInstance() {
 	}
 
 	@Override
-	public Class<?> getTestClass() {
-		return ((MethodTestDescriptor) getTestDescriptor()).getTestClass();
+	public Optional<Class<?>> getTestClass() {
+		return Optional.of(((MethodTestDescriptor) getTestDescriptor()).getTestClass());
 	}
 
 	@Override
@@ -66,7 +67,7 @@ public String getDisplayName() {
 
 	@Override
 	public AnnotatedElement getElement() {
-		return getTestMethod();
+		return getTestMethod().get();
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/MethodTestDescriptor.java

@@ -180,7 +180,7 @@ private void invokeTestMethod(ExtensionRegistry ExtensionRegistry, TestExtension
 
 		throwableCollector.execute(() -> {
 			MethodInvocationContext methodInvocationContext = methodInvocationContext(
-				testExtensionContext.getTestInstance(), testExtensionContext.getTestMethod());
+				testExtensionContext.getTestInstance(), testExtensionContext.getTestMethod().get());
 			try {
 				new MethodInvoker(testExtensionContext, ExtensionRegistry).invoke(methodInvocationContext);
 			}

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/extension/TestInfoParameterResolver.java

@@ -10,7 +10,9 @@
 
 package org.junit.gen5.engine.junit5.extension;
 
+import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
+import java.util.Optional;
 import java.util.Set;
 
 import org.junit.gen5.api.TestInfo;
@@ -36,22 +38,25 @@ public boolean supports(Parameter parameter, MethodInvocationContext methodInvoc
 
 	@Override
 	public TestInfo resolve(Parameter parameter, MethodInvocationContext methodInvocationContext,
-			final ExtensionContext extensionContext) {
+			ExtensionContext extensionContext) {
 
-		return new DefaultTestInfo(extensionContext.getName(), extensionContext.getDisplayName(),
-			extensionContext.getTags());
+		return new DefaultTestInfo(extensionContext);
 	}
 
 	private static class DefaultTestInfo implements TestInfo {
 
 		private final String name;
 		private final String displayName;
+		private final Optional<Class<?>> testClass;
+		private final Optional<Method> testMethod;
 		private final Set<String> tags;
 
-		DefaultTestInfo(String name, String displayName, Set<String> tags) {
-			this.name = name;
-			this.displayName = displayName;
-			this.tags = tags;
+		DefaultTestInfo(ExtensionContext extensionContext) {
+			this.name = extensionContext.getName();
+			this.displayName = extensionContext.getDisplayName();
+			this.testClass = extensionContext.getTestClass();
+			this.testMethod = extensionContext.getTestMethod();
+			this.tags = extensionContext.getTags();
 		}
 
 		@Override
@@ -69,6 +74,16 @@ public Set<String> getTags() {
 			return tags;
 		}
 
+		@Override
+		public Optional<Class<?>> getTestClass() {
+			return this.testClass;
+		}
+
+		@Override
+		public Optional<Method> getTestMethod() {
+			return this.testMethod;
+		}
+
 		@Override
 		public String toString() {
 			// @formatter:off