Fix test for save state cleanup on snapshot save / bug 297635 #460

The existing test TestBug297635 relies on reflection to test some
internal state change of the SavedState class that saves temporary
states until some save operation. The test was prone to fail because it
relied on internal state changes that depend an specific overall system
state (e.g., have an unsaved workspace state, so that no concurrent
automatic snapshot save is allowed to occur during test execution). It
used reflection to access an internal, highly volatile state.

The bug for which the test case serves as a regression test was due to
missing cleanup triggered by SavedState.forgetSavedTree(). Instead of
checking for internal state changes performed by the cleanup, the
rewritten test only checks for a call of the according method. To this
end, it temporarily inserts a spy on the SaveManager. Since a Workspace
and SaveManager are not easy to set up in an isolated way for testing
purposes, the test still relies on reflection, but only to inject a spy
on the SaveManager rather than to validate internal states.

Since the test is not required to be run as a session test anymore, it
is moved to the ordinary regression resource tests.

Fixes #460.

resources/tests/org.eclipse.core.tests.resources/META-INF/MANIFEST.MF

@@ -34,6 +34,7 @@ Require-Bundle: org.eclipse.core.resources,
  org.eclipse.core.filesystem,
  org.eclipse.core.runtime,
  org.eclipse.pde.junit.runtime;bundle-version="3.5.0"
+Import-Package: org.mockito
 Bundle-ActivationPolicy: lazy
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Eclipse-BundleShape: dir

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/regression/AllRegressionTests.java

@@ -25,8 +25,9 @@
 		Bug_029116.class, Bug_029671.class, Bug_029851.class, Bug_032076.class, Bug_044106.class, Bug_092108.class,
 		Bug_097608.class, Bug_098740.class, Bug_126104.class, Bug_127562.class, Bug_132510.class, Bug_134364.class,
 		Bug_147232.class, Bug_160251.class, Bug_165892.class, Bug_192631.class, Bug_226264.class, Bug_231301.class,
-		Bug_233939.class, Bug_265810.class, Bug_264182.class, Bug_288315.class, Bug_303517.class, Bug_329836.class,
-		Bug_331445.class, Bug_332543.class, Bug_378156.class, IFileTest.class, IFolderTest.class, IProjectTest.class,
+		Bug_233939.class, Bug_265810.class, Bug_264182.class, Bug_297635.class, Bug_288315.class, Bug_303517.class,
+		Bug_329836.class, Bug_331445.class, Bug_332543.class, Bug_378156.class,
+		IFileTest.class, IFolderTest.class, IProjectTest.class,
 		IResourceTest.class, IWorkspaceTest.class, LocalStoreRegressionTests.class, NLTest.class,
 		PR_1GEAB3C_Test.class,
 		PR_1GH2B0N_Test.class, PR_1GHOM0N_Test.class, Bug_530868.class, Bug_185247_recursiveLinks.class,

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/regression/Bug_297635.java

@@ -0,0 +1,154 @@
+/*******************************************************************************
+ *  Copyright (c) 2010, 2015 IBM Corporation and others.
+ *
+ *  This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License 2.0
+ *  which accompanies this distribution, and is available at
+ *  https://www.eclipse.org/legal/epl-2.0/
+ *
+ *  SPDX-License-Identifier: EPL-2.0
+ *
+ *  Contributors:
+ *     IBM Corporation - initial API and implementation
+ *     Alexander Kurtakov <akurtako@redhat.com> - Bug 459343
+ *******************************************************************************/
+package org.eclipse.core.tests.resources.regression;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import java.lang.reflect.Field;
+import java.util.function.Consumer;
+import org.eclipse.core.internal.resources.SaveManager;
+import org.eclipse.core.resources.ISaveContext;
+import org.eclipse.core.resources.ISaveParticipant;
+import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.tests.harness.BundleTestingHelper;
+import org.eclipse.core.tests.resources.ResourceTest;
+import org.eclipse.core.tests.resources.content.ContentTypeTest;
+import org.osgi.framework.Bundle;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.BundleException;
+
+/**
+ * Tests regression of bug 297635
+ */
+public class Bug_297635 extends ResourceTest {
+
+	@Override
+	protected void setUp() throws Exception {
+		super.setUp();
+		BundleWithSaveParticipant.install();
+		saveFull();
+	}
+
+	@Override
+	protected void tearDown() throws Exception {
+		BundleWithSaveParticipant.uninstall();
+		super.tearDown();
+	}
+
+	public void testCleanSaveStateBySaveParticipantOnSnapshotSave() throws Exception {
+		executeWithSaveManagerSpy(saveManagerSpy -> {
+			try {
+				saveSnapshot(saveManagerSpy);
+			} catch (CoreException e) {
+			}
+			verify(saveManagerSpy).forgetSavedTree(BundleWithSaveParticipant.getBundleName());
+		});
+	}
+
+	private void saveFull() throws CoreException {
+		getWorkspace().save(true, getMonitor());
+	}
+
+	private void saveSnapshot(SaveManager saveManager) throws CoreException {
+		saveManager.save(ISaveContext.SNAPSHOT, true, null, getMonitor());
+	}
+
+	private void executeWithSaveManagerSpy(Consumer<SaveManager> executeOnSpySaveManager) throws Exception {
+		IWorkspace workspace = getWorkspace();
+		String saveManagerFieldName = "saveManager";
+		SaveManager originalSaveManager = (SaveManager) getField(workspace, saveManagerFieldName);
+		SaveManager spySaveManager = spy(originalSaveManager);
+		try {
+			setField(workspace, saveManagerFieldName, spySaveManager);
+			executeOnSpySaveManager.accept(spySaveManager);
+		} finally {
+			setField(workspace, saveManagerFieldName, originalSaveManager);
+		}
+	}
+
+	private static Object getField(Object object, String fieldName) throws Exception {
+		Field field = object.getClass().getDeclaredField(fieldName);
+		field.setAccessible(true);
+		return field.get(object);
+	}
+
+	private static void setField(Object object, String fieldName, Object value) throws Exception {
+		Field field = object.getClass().getDeclaredField(fieldName);
+		field.setAccessible(true);
+		field.set(object, value);
+	}
+
+	private static final class BundleWithSaveParticipant {
+		private static String TEST_BUNDLE_LOCATION = "content/bundle01";
+
+		private static Bundle bundle;
+
+		private static ISaveParticipant saveParticipant = new ISaveParticipant() {
+			@Override
+			public void doneSaving(ISaveContext context) {
+				// nothing to do
+			}
+
+			@Override
+			public void prepareToSave(ISaveContext context) {
+				context.needDelta();
+				context.needSaveNumber();
+			}
+
+			@Override
+			public void rollback(ISaveContext context) {
+				// nothing to do
+			}
+
+			@Override
+			public void saving(ISaveContext context) {
+				// nothing to do
+			}
+		};
+
+		public static String getBundleName() {
+			if (bundle == null) {
+				throw new IllegalStateException("Bundle has not been installed");
+			}
+			return bundle.getSymbolicName();
+		}
+
+		public static void uninstall() throws BundleException {
+			if (bundle != null) {
+				bundle.uninstall();
+			}
+		}
+
+		public static void install() throws Exception {
+			bundle = BundleTestingHelper.installBundle("", getContext(),
+					ContentTypeTest.TEST_FILES_ROOT + TEST_BUNDLE_LOCATION);
+			BundleTestingHelper.resolveBundles(getContext(), new Bundle[] { bundle });
+			bundle.start(Bundle.START_TRANSIENT);
+			registerSaveParticipant(bundle);
+		}
+
+		private static BundleContext getContext() {
+			return Platform.getBundle(PI_RESOURCES_TESTS).getBundleContext();
+		}
+
+		private static void registerSaveParticipant(Bundle saveParticipantsBundle) throws CoreException {
+			getWorkspace().addSaveParticipant(saveParticipantsBundle.getSymbolicName(), saveParticipant);
+		}
+
+	}
+}

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/session/AllSessionTests.java

@@ -25,7 +25,7 @@
 		TestBug12575.class, WorkspaceDescriptionTest.class, TestBug30015.class,
 		TestMasterTableCleanup.class,
 		ProjectPreferenceSessionTest.class, TestBug113943.class, TestCreateLinkedResourceInHiddenProject.class,
-		Bug_266907.class, TestBug297635.class, TestBug323833.class,
+		Bug_266907.class, TestBug323833.class,
 		org.eclipse.core.tests.resources.regression.TestMultipleBuildersOfSameType.class,
 		org.eclipse.core.tests.resources.usecase.SnapshotTest.class, ProjectDescriptionDynamicTest.class,
 		TestBug202384.class, TestBug369177.class, TestBug316182.class, TestBug294854.class, TestBug426263.class,