Fix flaky PluginBasedLaunchTest by waiting for jobs and UI

The PluginBasedLaunchTest.testWriteBundleEntry_singleTargetPlugin_noVersionEntry failure appears to be a real issue caused by asynchronous updates to the plugin registry or target platform not completing before the test assertion.

This change adds a waitForJobsAndUI helper method to AbstractLaunchTest.java and invokes it within the getModel method. This ensures that the test waits for background jobs and processes the UI event loop, allowing the target platform to be fully loaded before asserting the model's presence.

Author: vogella

ui/org.eclipse.pde.ui.tests/src/org/eclipse/pde/ui/tests/launcher/AbstractLaunchTest.java

@@ -32,6 +32,7 @@
 
 import org.assertj.core.api.Assertions;
 import org.assertj.core.presentation.StandardRepresentation;
+import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.debug.core.DebugPlugin;
 import org.eclipse.debug.core.ILaunchConfiguration;
@@ -42,6 +43,7 @@
 import org.eclipse.pde.core.plugin.PluginRegistry;
 import org.eclipse.pde.ui.tests.util.ProjectUtils;
 import org.eclipse.pde.ui.tests.util.TargetPlatformUtil;
+import org.eclipse.swt.widgets.Display;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Rule;
@@ -82,6 +84,8 @@ public static IPluginModelBase findTargetModel(String id, String version) {
 	private static IPluginModelBase getModel(String id, String versionStr,
 			Function<ModelEntry, IPluginModelBase[]> modelsGetter, String type) {
 
+		waitForJobsAndUI(10000);
+
 		ModelEntry entry = PluginRegistry.findEntry(id);
 		assertNotNull("entry '" + id + "' should be present in PluginRegistry", entry);
 		IPluginModelBase[] models = modelsGetter.apply(entry);
@@ -98,6 +102,35 @@ private static IPluginModelBase getModel(String id, String versionStr,
 						() -> new NoSuchElementException("No " + type + " model " + id + "-" + version + " found"));
 	}
 
+	private static void waitForJobsAndUI(long timeoutMillis) {
+		long start = System.currentTimeMillis();
+
+		while (System.currentTimeMillis() - start < timeoutMillis) {
+			// Process UI events
+			while (Display.getDefault().readAndDispatch()) {
+				// Keep processing
+			}
+
+			// Check if all jobs are done
+			if (Job.getJobManager().isIdle()) {
+				// Process any final UI events
+				while (Display.getDefault().readAndDispatch()) {
+					// Keep processing
+				}
+				return;
+			}
+
+			try {
+				Thread.sleep(50);
+			} catch (InterruptedException e) {
+				Thread.currentThread().interrupt();
+				return;
+			}
+		}
+
+		// throw new AssertionError("Timeout waiting for jobs to complete");
+	}
+
 	static BundleLocationDescriptor workspaceBundle(String id, String version) {
 		Objects.requireNonNull(version);
 		return () -> findWorkspaceModel(id, version);