Load interceptors before session listeners

Author: marcphilipp

junit-platform-launcher/src/main/java/org/junit/platform/launcher/LauncherInterceptor.java

@@ -11,6 +11,9 @@
 package org.junit.platform.launcher;
 
 import static org.apiguardian.api.API.Status.EXPERIMENTAL;
+import static org.apiguardian.api.API.Status.INTERNAL;
+
+import java.util.List;
 
 import org.apiguardian.api.API;
 
@@ -28,6 +31,18 @@
 @API(status = EXPERIMENTAL, since = "1.10")
 public interface LauncherInterceptor {
 
+	LauncherInterceptor NOOP = new LauncherInterceptor() {
+		@Override
+		public <T> T intercept(Invocation<T> invocation) {
+			return invocation.proceed();
+		}
+
+		@Override
+		public void close() {
+			// do nothing
+		}
+	};
+
 	/**
 	 * Intercept the supplied invocation.
 	 *
@@ -54,4 +69,29 @@ public interface LauncherInterceptor {
 	interface Invocation<T> {
 		T proceed();
 	}
+
+	@API(status = INTERNAL, since = "1.10")
+	static LauncherInterceptor composite(List<LauncherInterceptor> interceptors) {
+		if (interceptors.isEmpty()) {
+			return NOOP;
+		}
+		return interceptors.stream() //
+				.skip(1) //
+				.reduce(interceptors.get(0), (a, b) -> new LauncherInterceptor() {
+					@Override
+					public void close() {
+						try {
+							a.close();
+						}
+						finally {
+							b.close();
+						}
+					}
+
+					@Override
+					public <T> T intercept(Invocation<T> invocation) {
+						return a.intercept(() -> b.intercept(invocation));
+					}
+				});
+	}
 }

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

@@ -28,17 +28,23 @@
  */
 class DefaultLauncherSession implements LauncherSession {
 
-	private final DelegatingCloseableLauncher<CloseableLauncher> launcher;
+	private final LauncherInterceptor interceptor;
 	private final LauncherSessionListener listener;
-
-	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;
+	private final DelegatingLauncher launcher;
+
+	DefaultLauncherSession(List<LauncherInterceptor> interceptors, Supplier<LauncherSessionListener> listenerSupplier,
+			Supplier<Launcher> launcherSupplier) {
+		interceptor = LauncherInterceptor.composite(interceptors);
+		Launcher launcher;
+		if (interceptor == LauncherInterceptor.NOOP) {
+			this.listener = listenerSupplier.get();
+			launcher = launcherSupplier.get();
+		}
+		else {
+			this.listener = interceptor.intercept(listenerSupplier::get);
+			launcher = new InterceptingLauncher(interceptor.intercept(launcherSupplier::get), interceptor);
+		}
+		this.launcher = new DelegatingLauncher(launcher);
 		listener.launcherSessionOpened(this);
 	}
 
@@ -53,13 +59,14 @@ LauncherSessionListener getListener() {
 
 	@Override
 	public void close() {
-		if (!launcher.isClosed()) {
-			launcher.close();
+		if (launcher.delegate != ClosedLauncher.INSTANCE) {
+			launcher.delegate = ClosedLauncher.INSTANCE;
 			listener.launcherSessionClosed(this);
+			interceptor.close();
 		}
 	}
 
-	private static class ClosedLauncher implements CloseableLauncher {
+	private static class ClosedLauncher implements Launcher {
 
 		static final ClosedLauncher INSTANCE = new ClosedLauncher();
 
@@ -90,10 +97,5 @@ public void execute(LauncherDiscoveryRequest launcherDiscoveryRequest, TestExecu
 		public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 			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/DefaultLauncherSession.java

@@ -19,11 +19,11 @@
 /**
  * @since 1.10
  */
-class DelegatingLauncher<T extends Launcher> implements Launcher {
+class DelegatingLauncher implements Launcher {
 
-	protected T delegate;
+	protected Launcher delegate;
 
-	DelegatingLauncher(T delegate) {
+	DelegatingLauncher(Launcher delegate) {
 		this.delegate = delegate;
 	}
 

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

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2015-2023 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 org.junit.platform.launcher.Launcher;
+import org.junit.platform.launcher.LauncherDiscoveryRequest;
+import org.junit.platform.launcher.LauncherInterceptor;
+import org.junit.platform.launcher.TestExecutionListener;
+import org.junit.platform.launcher.TestPlan;
+
+/**
+ * @since 1.10
+ */
+class InterceptingLauncher extends DelegatingLauncher {
+
+	private final LauncherInterceptor interceptor;
+
+	InterceptingLauncher(Launcher delegate, LauncherInterceptor interceptor) {
+		super(delegate);
+		this.interceptor = interceptor;
+	}
+
+	@Override
+	public TestPlan discover(LauncherDiscoveryRequest launcherDiscoveryRequest) {
+		return interceptor.intercept(() -> super.discover(launcherDiscoveryRequest));
+	}
+
+	@Override
+	public void execute(LauncherDiscoveryRequest launcherDiscoveryRequest, TestExecutionListener... listeners) {
+		interceptor.intercept(() -> {
+			super.execute(launcherDiscoveryRequest, listeners);
+			return null;
+		});
+	}
+
+	@Override
+	public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
+		interceptor.intercept(() -> {
+			super.execute(testPlan, listeners);
+			return null;
+		});
+	}
+}

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

@@ -100,8 +100,8 @@ public static LauncherSession openSession() throws PreconditionViolationExceptio
 	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),
-			collectLauncherInterceptors(configurationParameters), createLauncherSessionListener(config));
+		return new DefaultLauncherSession(collectLauncherInterceptors(configurationParameters),
+			() -> createLauncherSessionListener(config), () -> createDefaultLauncher(config, configurationParameters));
 	}
 
 	/**
@@ -131,7 +131,7 @@ public static Launcher create(LauncherConfig config) throws PreconditionViolatio
 		Preconditions.notNull(config, "LauncherConfig must not be null");
 		LauncherConfigurationParameters configurationParameters = LauncherConfigurationParameters.builder().build();
 		return new SessionPerRequestLauncher(() -> createDefaultLauncher(config, configurationParameters),
-			createLauncherSessionListener(config), () -> collectLauncherInterceptors(configurationParameters));
+			() -> createLauncherSessionListener(config), () -> collectLauncherInterceptors(configurationParameters));
 	}
 
 	private static DefaultLauncher createDefaultLauncher(LauncherConfig config,

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

@@ -29,13 +29,14 @@ class SessionPerRequestLauncher implements Launcher {
 
 	private final LauncherListenerRegistry listenerRegistry = new LauncherListenerRegistry();
 	private final Supplier<Launcher> launcherSupplier;
-	private final LauncherSessionListener sessionListener;
+	private final Supplier<LauncherSessionListener> sessionListenerSupplier;
 	private final Supplier<List<LauncherInterceptor>> interceptorFactory;
 
-	SessionPerRequestLauncher(Supplier<Launcher> launcherSupplier, LauncherSessionListener sessionListener,
+	SessionPerRequestLauncher(Supplier<Launcher> launcherSupplier,
+			Supplier<LauncherSessionListener> sessionListenerSupplier,
 			Supplier<List<LauncherInterceptor>> interceptorFactory) {
 		this.launcherSupplier = launcherSupplier;
-		this.sessionListener = sessionListener;
+		this.sessionListenerSupplier = sessionListenerSupplier;
 		this.interceptorFactory = interceptorFactory;
 	}
 
@@ -71,8 +72,8 @@ public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 	}
 
 	private LauncherSession createSession() {
-		LauncherSession session = new DefaultLauncherSession(launcherSupplier, interceptorFactory.get(),
-			sessionListener);
+		LauncherSession session = new DefaultLauncherSession(interceptorFactory.get(), sessionListenerSupplier,
+			launcherSupplier);
 		Launcher launcher = session.getLauncher();
 		listenerRegistry.launcherDiscoveryListeners.getListeners().forEach(
 			launcher::registerLauncherDiscoveryListeners);