TestEngine-specific context using type parameter

junit-engine-api/src/main/java/org/junit/gen5/engine/Child.java

@@ -1,8 +1,17 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine;
 
-public interface Child {
+public interface Child<C extends Context> {
 
-	Context execute(Context context) throws Throwable;
+	C execute(C context) throws Throwable;
 
 }

junit-engine-api/src/main/java/org/junit/gen5/engine/Context.java

@@ -1,29 +1,14 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine;
 
-import java.util.HashMap;
-import java.util.Map;
-
-public class Context {
-
-	private final Map<String, Object> map;
-
-	public Context() {
-		this(new HashMap<>());
-	}
-
-	private Context(Map<String, Object> map) {
-		this.map = map;
-	}
-
-	public Context with(String key, Object value) {
-		Map<String, Object> newMap = new HashMap<>(map);
-		newMap.put(key, value);
-		return new Context(newMap);
-	}
-
-	public <T> T get(String key, Class<T> clazz) {
-		return clazz.cast(map.get(key));
-	}
-
+public interface Context {
 }

junit-engine-api/src/main/java/org/junit/gen5/engine/Parent.java

@@ -1,10 +1,19 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine;
 
-public interface Parent {
+public interface Parent<C extends Context> {
 
-	Context beforeAll(Context context);
+	C beforeAll(C context);
 
-	Context afterAll(Context context);
+	C afterAll(C context);
 
 }

junit-engine-api/src/main/java/org/junit/gen5/engine/TreeBasedTestEngine.java

@@ -1,7 +1,16 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine;
 
-public abstract class TreeBasedTestEngine implements TestEngine {
+public abstract class TreeBasedTestEngine<C extends Context> implements TestEngine {
 
 	@Override
 	public abstract TestDescriptor discoverTests(TestPlanSpecification specification);
@@ -10,37 +19,38 @@ public abstract class TreeBasedTestEngine implements TestEngine {
 	public final void execute(ExecutionRequest request) {
 		try {
 			TestDescriptor rootTestDescriptor = request.getRootTestDescriptor();
-			executeAll(rootTestDescriptor, request.getEngineExecutionListener(), new Context());
+			executeAll(rootTestDescriptor, request.getEngineExecutionListener(), createContext());
 		}
 		catch (Exception e) {
 			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
 	}
 
-	private <T> void executeAll(TestDescriptor parentDescriptor, EngineExecutionListener listener,
-			Context parentContext) throws Exception {
-		Context context = parentContext;
+	protected abstract C createContext();
+
+	private <T> void executeAll(TestDescriptor parentDescriptor, EngineExecutionListener listener, C parentContext)
+			throws Exception {
+		C context = parentContext;
 		if (parentDescriptor instanceof Parent) {
-			context = ((Parent) parentDescriptor).beforeAll(context);
+			context = ((Parent<C>) parentDescriptor).beforeAll(context);
 		}
 		for (TestDescriptor childDescriptor : parentDescriptor.getChildren()) {
 			if (childDescriptor instanceof Child) {
-				Child child = (Child) childDescriptor;
+				Child<C> child = (Child<C>) childDescriptor;
 				try {
 					listener.testStarted(childDescriptor);
-					context = child.execute(context);
+					C childContext = child.execute(context);
 					listener.testSucceeded(childDescriptor);
 				}
 				catch (Throwable t) {
 					listener.testFailed(childDescriptor, t);
-					context = context.with("Throwable", t);
 				}
 			}
 			executeAll(childDescriptor, listener, context);
 		}
 		if (parentDescriptor instanceof Parent) {
-			context = ((Parent) parentDescriptor).afterAll(context);
+			context = ((Parent<C>) parentDescriptor).afterAll(context);
 		}
 	}
 

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5ClassDescriptor.java

@@ -1,12 +1,20 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine.junit5;
 
 import org.junit.gen5.commons.util.ReflectionUtils;
 import org.junit.gen5.engine.AbstractTestDescriptor;
-import org.junit.gen5.engine.Context;
 import org.junit.gen5.engine.Parent;
 
-public class JUnit5ClassDescriptor extends AbstractTestDescriptor implements Parent {
+public class JUnit5ClassDescriptor extends AbstractTestDescriptor implements Parent<JUnit5Context> {
 
 	private final Class<?> testClass;
 
@@ -31,12 +39,12 @@ public boolean isContainer() {
 	}
 
 	@Override
-	public Context beforeAll(Context context) {
-		return context.with("TestInstanceProvider", testInstanceProvider());
+	public JUnit5Context beforeAll(JUnit5Context context) {
+		return context.withTestInstanceProvider(testInstanceProvider());
 	}
 
 	@Override
-	public Context afterAll(Context context) {
+	public JUnit5Context afterAll(JUnit5Context context) {
 		return context;
 	}
 

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5Context.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.junit.gen5.engine.junit5;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.gen5.engine.Context;
+
+public class JUnit5Context implements Context {
+
+	private final Map<String, Object> map;
+
+	public JUnit5Context() {
+		this(new HashMap<>());
+	}
+
+	private JUnit5Context(Map<String, Object> map) {
+		this.map = map;
+	}
+
+	public JUnit5Context withTestInstanceProvider(TestInstanceProvider testInstanceProvider) {
+		return with(TestInstanceProvider.class.getName(), testInstanceProvider);
+	}
+
+	public TestInstanceProvider getTestInstanceProvider() {
+		return get(TestInstanceProvider.class.getName(), TestInstanceProvider.class);
+	}
+
+	private JUnit5Context with(String key, Object value) {
+		Map<String, Object> newMap = new HashMap<>(map);
+		newMap.put(key, value);
+		return new JUnit5Context(newMap);
+	}
+
+	private <T> T get(String key, Class<T> clazz) {
+		return clazz.cast(map.get(key));
+	}
+
+}

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5EngineDescriptor.java

@@ -1,3 +1,12 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine.junit5;
 

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5MethodDescriptor.java

@@ -1,3 +1,12 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine.junit5;
 
@@ -13,9 +22,8 @@
 import org.junit.gen5.commons.util.ReflectionUtils.MethodSortOrder;
 import org.junit.gen5.engine.AbstractTestDescriptor;
 import org.junit.gen5.engine.Child;
-import org.junit.gen5.engine.Context;
 
-public class JUnit5MethodDescriptor extends AbstractTestDescriptor implements Child {
+public class JUnit5MethodDescriptor extends AbstractTestDescriptor implements Child<JUnit5Context> {
 
 	private final Class<?> testClass;
 	private final Method method;
@@ -42,8 +50,8 @@ public boolean isContainer() {
 	}
 
 	@Override
-	public Context execute(Context context) throws Throwable {
-		TestInstanceProvider provider = context.get("TestInstanceProvider", TestInstanceProvider.class);
+	public JUnit5Context execute(JUnit5Context context) throws Throwable {
+		TestInstanceProvider provider = context.getTestInstanceProvider();
 		Object testInstance = provider.getTestInstance();
 		for (Method method : findAnnotatedMethods(testClass, BeforeEach.class, MethodSortOrder.HierarchyDown)) {
 			ReflectionUtils.invokeMethod(method, testInstance);

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5TestEngine.java

@@ -21,7 +21,7 @@
 import org.junit.gen5.engine.TestPlanSpecificationElementVisitor;
 import org.junit.gen5.engine.TreeBasedTestEngine;
 
-public class JUnit5TestEngine extends TreeBasedTestEngine {
+public class JUnit5TestEngine extends TreeBasedTestEngine<JUnit5Context> {
 
 	private static final String ENGINE_ID = "junit5";
 
@@ -51,4 +51,9 @@ public void visitClass(Class<?> testClass) {
 		});
 		return engineDescriptor;
 	}
+
+	@Override
+	protected JUnit5Context createContext() {
+		return new JUnit5Context();
+	}
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/TestInstanceProvider.java

@@ -1,3 +1,12 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v1.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
 
 package org.junit.gen5.engine.junit5;