Simplify/Clean-up code of o.e.pde.junit.runtime

ui/org.eclipse.pde.junit.runtime/META-INF/MANIFEST.MF

@@ -6,7 +6,6 @@ Bundle-Version: 3.7.200.qualifier
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
 Require-Bundle: org.eclipse.jdt.junit.runtime;bundle-version="[3.5.0,4.0.0)",
- org.junit;bundle-version="3.8.2",
  org.eclipse.core.runtime;bundle-version="[3.29.0,4.0.0)",
  org.eclipse.ui;bundle-version="[3.2.0,4.0.0)";resolution:=optional
 Export-Package: org.eclipse.pde.internal.junit.runtime;x-internal:=true

ui/org.eclipse.pde.junit.runtime/readme.txt

@@ -0,0 +1,18 @@
+ This PDE JUnit runtime is added to test-runtimes launched from an Eclipse workspace and allows JUnit tests to be run with an OSGi runtime.
+ It supports the following use cases:
+	1. Headless tests (no UI, no workbench)
+		Runs NonUIThreadTestApplication with no testable object
+	2. e4 UI tests (e4 UI, no workbench)
+		Runs NonUIThreadTestApplication with a testable object from e4 service
+	3. UI tests run in the non UI thread (UI, workbench)
+		Runs NonUIThreadTestApplication with a testable object from e4 service or PlatformUI
+	4. UI tests run in the UI thread (UI, workbench)
+		Runs UITestApplication with a testable object from e4 service or PlatformUI
+	5. Headless tests with no application (no UI, no workbench, no application)
+		Runs directly with no application
+
+If no pde.junit.runtime is available in the Target-Platform the one from the running Eclipse is added to the test-runtime.
+Of course users can target older Eclipse versions (which for example require older Java-versions), 
+which is why the requirements of this Plug-in should be as low as possible to make it resolve even in older runtimes.
+
+If changes are made, one should ensure that the requirement's lower-bounds specified in the MANIFEST.MF are still valid.

ui/org.eclipse.pde.junit.runtime/src/org/eclipse/pde/internal/junit/runtime/MultiBundleClassLoader.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- *  Copyright (c) 2018 IBM Corporation and others.
+ *  Copyright (c) 2018, 2023 IBM Corporation and others.
  *
  *  This program and the accompanying materials
  *  are made available under the terms of the Eclipse Public License 2.0
@@ -36,8 +36,9 @@ protected Class<?> findClass(String name) throws ClassNotFoundException {
 		for (Bundle temp : bundleList) {
 			try {
 				Class<?> c = temp.loadClass(name);
-				if (c != null)
+				if (c != null) {
 					return c;
+				}
 			} catch (ClassNotFoundException e) {
 			}
 		}
@@ -46,9 +47,8 @@ protected Class<?> findClass(String name) throws ClassNotFoundException {
 
 	@Override
 	protected URL findResource(String name) {
-		URL url = null;
 		for (Bundle temp : bundleList) {
-			url = temp.getResource(name);
+			URL url = temp.getResource(name);
 			if (url != null) {
 				try {
 					return FileLocator.resolve(url);
@@ -57,7 +57,7 @@ protected URL findResource(String name) {
 				}
 			}
 		}
-		return url;
+		return null;
 	}
 
 	@Override

ui/org.eclipse.pde.junit.runtime/src/org/eclipse/pde/internal/junit/runtime/NonUIThreadTestApplication.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2015 EclipseSource Corporation and others.
+ * Copyright (c) 2009, 2023 EclipseSource Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -13,14 +13,19 @@
  *******************************************************************************/
 package org.eclipse.pde.internal.junit.runtime;
 
+import java.util.Objects;
+
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IProduct;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.equinox.app.IApplication;
 import org.eclipse.equinox.app.IApplicationContext;
-import org.junit.Assert;
+import org.eclipse.ui.testing.TestableObject;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.FrameworkUtil;
+import org.osgi.framework.ServiceReference;
 
 /**
  * A Workbench that runs a test suite specified in the
@@ -32,14 +37,14 @@ public class NonUIThreadTestApplication implements IApplication {
 
 	protected IApplication fApplication;
 	protected Object fTestHarness;
+	protected boolean requirePlatformUI = false;
 
 	@Override
 	public Object start(IApplicationContext context) throws Exception {
 		String[] args = (String[]) context.getArguments().get(IApplicationContext.APPLICATION_ARGS);
 
 		String appId = getApplicationToRun(args);
-		IApplication app = getApplication(appId);
-		Assert.assertNotNull(app);
+		IApplication app = Objects.requireNonNull(getApplication(appId));
 
 		if (!DEFAULT_HEADLESSAPP.equals(appId)) {
 			// this means we are running a different application, which potentially can be UI application;
@@ -48,11 +53,6 @@ public Object start(IApplicationContext context) throws Exception {
 			// (see bug 340906 for details)
 			installPlatformUITestHarness();
 		}
-
-		return runApp(app, context);
-	}
-
-	protected Object runApp(IApplication app, IApplicationContext context) throws Exception {
 		fApplication = app;
 		return fApplication.start(context);
 	}
@@ -66,27 +66,53 @@ protected Object runApp(IApplication app, IApplicationContext context) throws Ex
 	 *
 	 * @throws Exception
 	 */
-	private void installPlatformUITestHarness() throws Exception {
-		Object testableObject = PDEJUnitRuntimePlugin.getDefault().getTestableObject();
+	private void installPlatformUITestHarness() throws ReflectiveOperationException {
+		Object testableObject = getRegisteredTestableObject();
 		if (testableObject == null) {
-			try {
+			try { // If the service doesn't return a testable object ask PlatformUI directly
 				Class<?> platformUIClass = Class.forName("org.eclipse.ui.PlatformUI", true, getClass().getClassLoader()); //$NON-NLS-1$
 				testableObject = platformUIClass.getMethod("getTestableObject").invoke(null); //$NON-NLS-1$
-			} catch (ClassNotFoundException e) {
-				// PlatformUI is not available
+			} catch (ClassNotFoundException e) { // PlatformUI is not available
+				if (requirePlatformUI) {
+					throw e;
+				}
 			}
 		}
 		if (testableObject != null) {
 			fTestHarness = new PlatformUITestHarness(testableObject, true);
 		}
 	}
 
+	/**
+	 * Returns a {@link TestableObject} provided by a TestableObject service or {@code null} if no implementation can be found.
+	 * The TestableObject is used to hook tests into the application lifecycle.
+	 * <p>
+	 * It is recommended the testable object is obtained via service instead Workbench#getWorkbenchTestable() to avoid
+	 * the tests having a dependency on the Workbench.
+	 * </p>
+	 * @return TestableObject provided via service or {@code null}
+	 */
+	private static Object getRegisteredTestableObject() {
+		BundleContext context = FrameworkUtil.getBundle(NonUIThreadTestApplication.class).getBundleContext();
+		ServiceReference<?> reference = context.getServiceReference("org.eclipse.ui.testing.TestableObject"); //$NON-NLS-1$
+		if (reference != null) {
+			try {
+				return context.getService(reference);
+			} finally {
+				context.ungetService(reference);
+			}
+		}
+		return null;
+	}
+
 	@Override
 	public void stop() {
-		if (fApplication != null)
+		if (fApplication != null) {
 			fApplication.stop();
-		if (fTestHarness != null)
+		}
+		if (fTestHarness != null) {
 			fTestHarness = null;
+		}
 	}
 
 	/*
@@ -98,8 +124,7 @@ private IApplication getApplication(String appId) throws CoreException {
 		// If no application is specified, the 3.0 default workbench application
 		// is returned.
 		IExtension extension = Platform.getExtensionRegistry().getExtension(Platform.PI_RUNTIME, Platform.PT_APPLICATIONS, appId);
-
-		Assert.assertNotNull(extension);
+		Objects.requireNonNull(extension);
 
 		// If the extension does not have the correct grammar, return null.
 		// Otherwise, return the application object.
@@ -108,8 +133,9 @@ private IApplication getApplication(String appId) throws CoreException {
 			IConfigurationElement[] runs = elements[0].getChildren("run"); //$NON-NLS-1$
 			if (runs.length > 0) {
 				Object runnable = runs[0].createExecutableExtension("class"); //$NON-NLS-1$
-				if (runnable instanceof IApplication)
+				if (runnable instanceof IApplication) {
 					return (IApplication) runnable;
+				}
 			}
 		}
 		return null;
@@ -125,14 +151,12 @@ private IApplication getApplication(String appId) throws CoreException {
 	 *
 	 */
 	private String getApplicationToRun(String[] args) {
-		for (int i = 0; i < args.length; i++) {
-			if (args[i].equals("-testApplication") && i < args.length - 1) //$NON-NLS-1$
-				return args[i + 1];
+		String testApp = RemotePluginTestRunner.getArgumentValue(args, "-testApplication"); //$NON-NLS-1$
+		if (testApp != null) {
+			return testApp;
 		}
 		IProduct product = Platform.getProduct();
-		if (product != null)
-			return product.getApplication();
-		return getDefaultApplicationId();
+		return product != null ? product.getApplication() : getDefaultApplicationId();
 	}
 
 	protected String getDefaultApplicationId() {

ui/org.eclipse.pde.junit.runtime/src/org/eclipse/pde/internal/junit/runtime/PlatformUITestHarness.java

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2011, 2015 Gunnar Wagenknecht and others.
+ * Copyright (c) 2011, 2023 Gunnar Wagenknecht and others.
  * All rights reserved.
  *
  * This program and the accompanying materials are made available under the terms of the
@@ -47,7 +47,7 @@ public void runTests() {
 			if (fRunTestsInSeparateThread) {
 				// wrap into separate thread and run from there
 				final Thread testRunnerThread = new Thread(testsRunner, "Plug-in Tests Runner"); //$NON-NLS-1$
-				fTestableObject.runTest(() -> testRunnerThread.start());
+				fTestableObject.runTest(testRunnerThread::start);
 
 				// wait for tests to finish
 				// note, this has do be done outside #runTest method to not lock the UI