Create interceptors before launcher

So they can influence the class loader used to load test engines etc.

Author: marcphilipp

junit-platform-engine/src/testFixtures/java/org/junit/platform/fakes/TestEngineSpy.java

@@ -21,19 +21,27 @@
  */
 public class TestEngineSpy implements TestEngine {
 
-	public static final String ID = TestEngineSpy.class.getSimpleName();
+	private final String id;
 
 	public ExecutionRequest requestForExecution;
 
+	public TestEngineSpy() {
+		this(TestEngineSpy.class.getSimpleName());
+	}
+
+	public TestEngineSpy(String id) {
+		this.id = id;
+	}
+
 	@Override
 	public String getId() {
-		return ID;
+		return id;
 	}
 
 	@Override
 	public TestDescriptor discover(EngineDiscoveryRequest discoveryRequest, UniqueId uniqueId) {
-		var engineUniqueId = UniqueId.forEngine(ID);
-		var engineDescriptor = new TestDescriptorStub(engineUniqueId, ID);
+		var engineUniqueId = UniqueId.forEngine(id);
+		var engineDescriptor = new TestDescriptorStub(engineUniqueId, id);
 		var testDescriptor = new TestDescriptorStub(engineUniqueId.append("test", "test"), "test");
 		engineDescriptor.addChild(testDescriptor);
 		return engineDescriptor;

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/CloseableInternalLauncher.java renamed to junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/CloseableLauncher.java

@@ -10,10 +10,12 @@
 
 package org.junit.platform.launcher.core;
 
+import org.junit.platform.launcher.Launcher;
+
 /**
  * @since 1.10
  */
-interface CloseableInternalLauncher extends InternalLauncher, AutoCloseable {
+interface CloseableLauncher extends Launcher, AutoCloseable {
 	@Override
 	void close();
 }

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DefaultLauncher.java

@@ -35,12 +35,11 @@
  * @see Launcher
  * @see LauncherFactory
  */
-class DefaultLauncher implements InternalLauncher {
+class DefaultLauncher implements Launcher {
 
-	private final ListenerRegistry<LauncherDiscoveryListener> launcherDiscoveryListenerRegistry = ListenerRegistry.forLauncherDiscoveryListeners();
-	private final ListenerRegistry<TestExecutionListener> testExecutionListenerRegistry = ListenerRegistry.forTestExecutionListeners();
+	private final LauncherListenerRegistry listenerRegistry = new LauncherListenerRegistry();
 	private final EngineExecutionOrchestrator executionOrchestrator = new EngineExecutionOrchestrator(
-		testExecutionListenerRegistry);
+		listenerRegistry.testExecutionListeners);;
 	private final EngineDiscoveryOrchestrator discoveryOrchestrator;
 
 	/**
@@ -59,17 +58,17 @@ class DefaultLauncher implements InternalLauncher {
 		Preconditions.containsNoNullElements(postDiscoveryFilters,
 			"PostDiscoveryFilter array must not contain null elements");
 		this.discoveryOrchestrator = new EngineDiscoveryOrchestrator(testEngines,
-			unmodifiableCollection(postDiscoveryFilters), launcherDiscoveryListenerRegistry);
+			unmodifiableCollection(postDiscoveryFilters), listenerRegistry.launcherDiscoveryListeners);
 	}
 
 	@Override
 	public void registerLauncherDiscoveryListeners(LauncherDiscoveryListener... listeners) {
-		this.launcherDiscoveryListenerRegistry.addAll(listeners);
+		this.listenerRegistry.launcherDiscoveryListeners.addAll(listeners);
 	}
 
 	@Override
 	public void registerTestExecutionListeners(TestExecutionListener... listeners) {
-		this.testExecutionListenerRegistry.addAll(listeners);
+		this.listenerRegistry.testExecutionListeners.addAll(listeners);
 	}
 
 	@Override
@@ -95,16 +94,6 @@ public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 		execute((InternalTestPlan) testPlan, listeners);
 	}
 
-	@Override
-	public ListenerRegistry<TestExecutionListener> getTestExecutionListenerRegistry() {
-		return testExecutionListenerRegistry;
-	}
-
-	@Override
-	public ListenerRegistry<LauncherDiscoveryListener> getLauncherDiscoveryListenerRegistry() {
-		return launcherDiscoveryListenerRegistry;
-	}
-
 	private LauncherDiscoveryResult discover(LauncherDiscoveryRequest discoveryRequest,
 			EngineDiscoveryOrchestrator.Phase phase) {
 		return discoveryOrchestrator.discover(discoveryRequest, phase);

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DefaultLauncherSession.java

@@ -11,6 +11,7 @@
 package org.junit.platform.launcher.core;
 
 import java.util.List;
+import java.util.function.Supplier;
 
 import org.junit.platform.commons.PreconditionViolationException;
 import org.junit.platform.launcher.Launcher;
@@ -27,12 +28,16 @@
  */
 class DefaultLauncherSession implements LauncherSession {
 
-	private final DelegatingLauncher launcher;
+	private final DelegatingCloseableLauncher<CloseableLauncher> launcher;
 	private final LauncherSessionListener listener;
 
-	DefaultLauncherSession(InternalLauncher launcher, LauncherSessionListener listener,
-			List<LauncherInterceptor> interceptors) {
-		this.launcher = new DelegatingLauncher(InterceptingInternalLauncher.decorate(launcher, interceptors));
+	DefaultLauncherSession(Supplier<Launcher> launcherSupplier, List<LauncherInterceptor> interceptors,
+			LauncherSessionListener listener) {
+		CloseableLauncher closeableLauncher = InterceptingClosableLauncher.decorate(launcherSupplier, interceptors);
+		this.launcher = new DelegatingCloseableLauncher<>(closeableLauncher, delegate -> {
+			delegate.close();
+			return ClosedLauncher.INSTANCE;
+		});
 		this.listener = listener;
 		listener.launcherSessionOpened(this);
 	}
@@ -48,31 +53,13 @@ LauncherSessionListener getListener() {
 
 	@Override
 	public void close() {
-		if (launcher.isClosed()) {
+		if (!launcher.isClosed()) {
 			launcher.close();
 			listener.launcherSessionClosed(this);
 		}
 	}
 
-	private static class DelegatingLauncher extends DelegatingInternalLauncher<CloseableInternalLauncher>
-			implements CloseableInternalLauncher {
-
-		DelegatingLauncher(CloseableInternalLauncher delegate) {
-			super(delegate);
-		}
-
-		boolean isClosed() {
-			return delegate != ClosedLauncher.INSTANCE;
-		}
-
-		@Override
-		public void close() {
-			delegate.close();
-			delegate = ClosedLauncher.INSTANCE;
-		}
-	}
-
-	private static class ClosedLauncher implements CloseableInternalLauncher {
+	private static class ClosedLauncher implements CloseableLauncher {
 
 		static final ClosedLauncher INSTANCE = new ClosedLauncher();
 
@@ -104,16 +91,6 @@ public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 			throw new PreconditionViolationException("Launcher session has already been closed");
 		}
 
-		@Override
-		public ListenerRegistry<TestExecutionListener> getTestExecutionListenerRegistry() {
-			throw new PreconditionViolationException("Launcher session has already been closed");
-		}
-
-		@Override
-		public ListenerRegistry<LauncherDiscoveryListener> getLauncherDiscoveryListenerRegistry() {
-			throw new PreconditionViolationException("Launcher session has already been closed");
-		}
-
 		@Override
 		public void close() {
 			// do nothing

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DelegatingCloseableInternalLauncher.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2015-2022 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 v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * https://www.eclipse.org/legal/epl-v20.html
+ */
+
+package org.junit.platform.launcher.core;
+
+import java.util.function.Function;
+
+import org.junit.platform.launcher.Launcher;
+
+/**
+ * @since 1.10
+ */
+class DelegatingCloseableLauncher<T extends Launcher> extends DelegatingLauncher<T> implements CloseableLauncher {
+
+	private final Function<? super T, ? extends T> onClose;
+	private boolean closed;
+
+	public DelegatingCloseableLauncher(T delegate, Function<? super T, ? extends T> onClose) {
+		super(delegate);
+		this.onClose = onClose;
+	}
+
+	@Override
+	public final void close() {
+		if (!closed) {
+			this.closed = true;
+			delegate = this.onClose.apply(this.delegate);
+		}
+	}
+
+	public boolean isClosed() {
+		return closed;
+	}
+}

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DelegatingCloseableLauncher.java

@@ -10,6 +10,7 @@
 
 package org.junit.platform.launcher.core;
 
+import org.junit.platform.launcher.Launcher;
 import org.junit.platform.launcher.LauncherDiscoveryListener;
 import org.junit.platform.launcher.LauncherDiscoveryRequest;
 import org.junit.platform.launcher.TestExecutionListener;
@@ -18,11 +19,11 @@
 /**
  * @since 1.10
  */
-class DelegatingInternalLauncher<T extends InternalLauncher> implements InternalLauncher {
+class DelegatingLauncher<T extends Launcher> implements Launcher {
 
 	protected T delegate;
 
-	DelegatingInternalLauncher(T delegate) {
+	DelegatingLauncher(T delegate) {
 		this.delegate = delegate;
 	}
 
@@ -51,13 +52,4 @@ public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 		delegate.execute(testPlan, listeners);
 	}
 
-	@Override
-	public ListenerRegistry<TestExecutionListener> getTestExecutionListenerRegistry() {
-		return delegate.getTestExecutionListenerRegistry();
-	}
-
-	@Override
-	public ListenerRegistry<LauncherDiscoveryListener> getLauncherDiscoveryListenerRegistry() {
-		return delegate.getLauncherDiscoveryListenerRegistry();
-	}
 }

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DelegatingInternalLauncher.java renamed to junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DelegatingLauncher.java

@@ -10,9 +10,13 @@
 
 package org.junit.platform.launcher.core;
 
+import static java.util.function.Function.identity;
+
 import java.util.List;
 import java.util.Optional;
+import java.util.function.Supplier;
 
+import org.junit.platform.launcher.Launcher;
 import org.junit.platform.launcher.LauncherDiscoveryRequest;
 import org.junit.platform.launcher.LauncherInterceptor;
 import org.junit.platform.launcher.TestExecutionListener;
@@ -21,15 +25,15 @@
 /**
  * @since 1.10
  */
-class InterceptingInternalLauncher extends DelegatingCloseableInternalLauncher<InternalLauncher> {
+class InterceptingClosableLauncher extends DelegatingCloseableLauncher<Launcher> {
 
-	static CloseableInternalLauncher decorate(InternalLauncher launcher, List<LauncherInterceptor> interceptors) {
-		return composite(interceptors) //
-				.map(combinedInterceptor -> (CloseableInternalLauncher) new InterceptingInternalLauncher(launcher,
-					combinedInterceptor)) //
-				.orElse(new DelegatingCloseableInternalLauncher<>(launcher, () -> {
-					// do nothing
-				}));
+	static CloseableLauncher decorate(Supplier<Launcher> launcherSupplier, List<LauncherInterceptor> interceptors) {
+		Optional<LauncherInterceptor> combinedInterceptor = composite(interceptors);
+		Launcher launcher = combinedInterceptor.map(it -> it.intercept(launcherSupplier::get)).orElseGet(
+			launcherSupplier);
+		return combinedInterceptor //
+				.map(it -> (CloseableLauncher) new InterceptingClosableLauncher(launcher, it)) //
+				.orElse(new DelegatingCloseableLauncher<>(launcher, identity()));
 	}
 
 	private static Optional<LauncherInterceptor> composite(List<LauncherInterceptor> interceptors) {
@@ -58,8 +62,11 @@ public <T> T intercept(Invocation<T> invocation) {
 
 	private final LauncherInterceptor interceptor;
 
-	private InterceptingInternalLauncher(InternalLauncher delegate, LauncherInterceptor interceptor) {
-		super(delegate, interceptor::close);
+	private InterceptingClosableLauncher(Launcher delegate, LauncherInterceptor interceptor) {
+		super(delegate, it -> {
+			interceptor.close();
+			return it;
+		});
 		this.interceptor = interceptor;
 	}
 

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/InterceptingInternalLauncher.java renamed to junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/InterceptingClosableLauncher.java

@@ -98,9 +98,10 @@ public static LauncherSession openSession() throws PreconditionViolationExceptio
 	 */
 	@API(status = EXPERIMENTAL, since = "1.8")
 	public static LauncherSession openSession(LauncherConfig config) throws PreconditionViolationException {
+		Preconditions.notNull(config, "LauncherConfig must not be null");
 		LauncherConfigurationParameters configurationParameters = LauncherConfigurationParameters.builder().build();
-		return new DefaultLauncherSession(createDefaultLauncher(config, configurationParameters),
-			createLauncherSessionListener(config), collectLauncherInterceptors(configurationParameters));
+		return new DefaultLauncherSession(() -> createDefaultLauncher(config, configurationParameters),
+			collectLauncherInterceptors(configurationParameters), createLauncherSessionListener(config));
 	}
 
 	/**
@@ -127,15 +128,14 @@ public static Launcher create() throws PreconditionViolationException {
 	 */
 	@API(status = EXPERIMENTAL, since = "1.3")
 	public static Launcher create(LauncherConfig config) throws PreconditionViolationException {
+		Preconditions.notNull(config, "LauncherConfig must not be null");
 		LauncherConfigurationParameters configurationParameters = LauncherConfigurationParameters.builder().build();
-		return new SessionPerRequestLauncher(createDefaultLauncher(config, configurationParameters),
+		return new SessionPerRequestLauncher(() -> createDefaultLauncher(config, configurationParameters),
 			createLauncherSessionListener(config), () -> collectLauncherInterceptors(configurationParameters));
 	}
 
 	private static DefaultLauncher createDefaultLauncher(LauncherConfig config,
 			LauncherConfigurationParameters configurationParameters) {
-		Preconditions.notNull(config, "LauncherConfig must not be null");
-
 		Set<TestEngine> engines = collectTestEngines(config);
 		List<PostDiscoveryFilter> filters = collectPostDiscoveryFilters(config);
 

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/LauncherFactory.java

@@ -10,16 +10,10 @@
 
 package org.junit.platform.launcher.core;
 
-import org.junit.platform.launcher.Launcher;
 import org.junit.platform.launcher.LauncherDiscoveryListener;
 import org.junit.platform.launcher.TestExecutionListener;
 
-/**
- * @since 1.8
- */
-interface InternalLauncher extends Launcher {
-
-	ListenerRegistry<TestExecutionListener> getTestExecutionListenerRegistry();
-
-	ListenerRegistry<LauncherDiscoveryListener> getLauncherDiscoveryListenerRegistry();
+class LauncherListenerRegistry {
+	final ListenerRegistry<LauncherDiscoveryListener> launcherDiscoveryListeners = ListenerRegistry.forLauncherDiscoveryListeners();
+	final ListenerRegistry<TestExecutionListener> testExecutionListeners = ListenerRegistry.forTestExecutionListeners();
 }