Log resource deltas during MarkerTest.testMarkerDeltasMoveFile

MarkerTest.testMarkerDeltasMoveFile fails infrequently,
due to unexpected deltas received by the test resource change listener.
The expected cause is a race condition, likely a parallel job
notifying about the resource delta instead of the test main thread.

This change adds logging for resource deltas, including the thread
which notifies about the resource delta. This information hopefully
helps to identify the potential race condition.

See: #2569

Author: trancexpress

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/MarkerTest.java

@@ -55,13 +55,18 @@
 import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.IResourceChangeEvent;
+import org.eclipse.core.resources.IResourceChangeListener;
+import org.eclipse.core.resources.IResourceDelta;
+import org.eclipse.core.resources.IResourceDeltaVisitor;
 import org.eclipse.core.resources.IResourceVisitor;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.InstanceScope;
@@ -75,6 +80,8 @@
 @ExtendWith(WorkspaceResetExtension.class)
 public class MarkerTest {
 
+	private static final IResourceChangeListener LOG_RESOURCE_DELTA = MarkerTest::logDeltaEvent;
+
 	public static final String TRANSIENT_MARKER = "org.eclipse.core.tests.resources.transientmarker";
 	public static final String TEST_PROBLEM_MARKER = "org.eclipse.core.tests.resources.testproblem";
 
@@ -211,6 +218,7 @@ public void tearDown() throws Exception {
 		}
 		IEclipsePreferences prefs = InstanceScope.INSTANCE.getNode(ResourcesPlugin.PI_RESOURCES);
 		prefs.putBoolean(ResourcesPlugin.PREF_AUTO_REFRESH, originalRefreshSetting);
+		ResourcesPlugin.getWorkspace().removeResourceChangeListener(LOG_RESOURCE_DELTA);
 	}
 
 	/**
@@ -950,6 +958,7 @@ public void testMarkerDeltasMoveFolder(TestInfo testInfo) throws CoreException {
 	 */
 	@Test
 	public void testMarkerDeltasMoveFile(TestInfo testInfo) throws CoreException {
+		ResourcesPlugin.getWorkspace().addResourceChangeListener(LOG_RESOURCE_DELTA);
 		IWorkspaceRoot root = getWorkspace().getRoot();
 		final IProject project = root.getProject("MyProject");
 		IFolder folder = project.getFolder("folder");
@@ -1384,4 +1393,50 @@ public void testSetGetAttribute2() throws CoreException {
 		}
 	}
 
+	private static void logDeltaEvent(IResourceChangeEvent event) {
+		StringBuilder s = new StringBuilder();
+		s.append("Logging resource change event");
+		s.append(System.lineSeparator());
+		s.append("thread: ");
+		s.append(Thread.currentThread().getName());
+		s.append(System.lineSeparator());
+		s.append("type: ");
+		s.append(event.getType());
+		s.append(System.lineSeparator());
+		s.append("buildKind: ");
+		s.append(event.getBuildKind());
+		s.append(System.lineSeparator());
+		s.append("resource: ");
+		s.append(event.getResource());
+		s.append(System.lineSeparator());
+		s.append("source: ");
+		s.append(event.getSource());
+		IResourceDelta delta = event.getDelta();
+		if (delta != null) {
+			s.append(System.lineSeparator());
+			s.append("Delta:");
+			IResourceDeltaVisitor visitor = d -> {
+				s.append(System.lineSeparator());
+				s.append("\tkind: ");
+				s.append(d.getKind());
+				s.append(", resource: ");
+				s.append(d.getResource());
+				return true;
+			};
+			try {
+				delta.accept(visitor);
+			} catch (CoreException e) {
+				logError("Error occurred while visiting delta", e);
+			}
+			logInfo(s.toString());
+		}
+	}
+
+	private static void logError(String errorMessage, CoreException e) {
+		ResourcesPlugin.getPlugin().getLog().log(Status.error(errorMessage, e));
+	}
+
+	private static void logInfo(String message) {
+		ResourcesPlugin.getPlugin().getLog().log(Status.info(message));
+	}
 }