Call LauncherDiscoveryListener.class finish methods in reverse order

Author: marcphilipp

junit-platform-launcher/src/main/java/org/junit/platform/launcher/listeners/discovery/CompositeLauncherDiscoveryListener.java

@@ -10,6 +10,8 @@
 
 package org.junit.platform.launcher.listeners.discovery;
 
+import static org.junit.platform.commons.util.CollectionUtils.forEachInReverseOrder;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -40,7 +42,7 @@ public void launcherDiscoveryStarted(LauncherDiscoveryRequest request) {
 
 	@Override
 	public void launcherDiscoveryFinished(LauncherDiscoveryRequest request) {
-		listeners.forEach(delegate -> delegate.launcherDiscoveryFinished(request));
+		forEachInReverseOrder(listeners, delegate -> delegate.launcherDiscoveryFinished(request));
 	}
 
 	@Override
@@ -50,7 +52,7 @@ public void engineDiscoveryStarted(UniqueId engineId) {
 
 	@Override
 	public void engineDiscoveryFinished(UniqueId engineId, EngineDiscoveryResult result) {
-		listeners.forEach(delegate -> delegate.engineDiscoveryFinished(engineId, result));
+		forEachInReverseOrder(listeners, delegate -> delegate.engineDiscoveryFinished(engineId, result));
 	}
 
 	@Override

platform-tests/src/test/java/org/junit/platform/launcher/listeners/discovery/CompositeLauncherDiscoveryListenerTests.java

@@ -0,0 +1,58 @@
+/*
+ * 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.listeners.discovery;
+
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectUniqueId;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.platform.engine.SelectorResolutionResult;
+import org.junit.platform.engine.UniqueId;
+import org.junit.platform.launcher.EngineDiscoveryResult;
+import org.junit.platform.launcher.LauncherDiscoveryListener;
+import org.junit.platform.launcher.LauncherDiscoveryRequest;
+import org.mockito.InOrder;
+
+class CompositeLauncherDiscoveryListenerTests {
+
+	@Test
+	void callsListenersInReverseOrderForFinishedEvents() {
+		var firstListener = mock(LauncherDiscoveryListener.class, "firstListener");
+		var secondListener = mock(LauncherDiscoveryListener.class, "secondListener");
+
+		var launcherDiscoveryRequest = mock(LauncherDiscoveryRequest.class);
+		var engineId = UniqueId.forEngine("engine");
+		var engineDiscoveryResult = EngineDiscoveryResult.successful();
+		var selector = selectUniqueId(engineId);
+		var selectorResolutionResult = SelectorResolutionResult.resolved();
+
+		var composite = new CompositeLauncherDiscoveryListener(List.of(firstListener, secondListener));
+		composite.launcherDiscoveryStarted(launcherDiscoveryRequest);
+		composite.engineDiscoveryStarted(engineId);
+		composite.selectorProcessed(engineId, selector, selectorResolutionResult);
+		composite.engineDiscoveryFinished(engineId, engineDiscoveryResult);
+		composite.launcherDiscoveryFinished(launcherDiscoveryRequest);
+
+		InOrder inOrder = inOrder(firstListener, secondListener);
+		inOrder.verify(firstListener).launcherDiscoveryStarted(launcherDiscoveryRequest);
+		inOrder.verify(secondListener).launcherDiscoveryStarted(launcherDiscoveryRequest);
+		inOrder.verify(firstListener).engineDiscoveryStarted(engineId);
+		inOrder.verify(secondListener).engineDiscoveryStarted(engineId);
+		inOrder.verify(secondListener).selectorProcessed(engineId, selector, selectorResolutionResult);
+		inOrder.verify(secondListener).engineDiscoveryFinished(engineId, engineDiscoveryResult);
+		inOrder.verify(firstListener).engineDiscoveryFinished(engineId, engineDiscoveryResult);
+		inOrder.verify(secondListener).launcherDiscoveryFinished(launcherDiscoveryRequest);
+		inOrder.verify(firstListener).launcherDiscoveryFinished(launcherDiscoveryRequest);
+	}
+}