VirtualLazyTreeViewerTest: avoid silent failures and force active shell

Several tests in VirtualLazyTreeViewerTest silently fail because the
tree data is not set and the test then simply returns as succeeding.
This change does the following:
* Force shell activation to avoid the silent test failures
* Make that the variable identifying data to be set volatile to be
consistent across threads
* Make the tests fail explicitly rather than silently

Contributes to
#1583

Author: HeikoKlare

tests/org.eclipse.jface.tests/src/org/eclipse/jface/tests/viewers/VirtualLazyTreeViewerTest.java

@@ -18,23 +18,19 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeFalse;
 
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Tree;
 import org.junit.Ignore;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.TestName;
 
 public class VirtualLazyTreeViewerTest extends TreeViewerTest {
 
-	@Rule
-	public TestName testName = new TestName();
-
-	protected int setDataCalls = 0;
+	protected volatile int setDataCalls = 0;
 
 	@Override
 	protected StructuredViewer createViewer(Composite parent) {
@@ -48,6 +44,7 @@ protected StructuredViewer createViewer(Composite parent) {
 	@Override
 	public void setUp() {
 		super.setUp();
+		fShell.forceActive();
 		// process events because the content provider uses an asyncExec to set the item
 		// count of the tree
 		processEvents();
@@ -117,7 +114,6 @@ public void testInsertSiblingWithFilterNotFiltered() {
 	@Ignore("no need to test since virtual trees do not support sorting")
 	@Override
 	public void testInsertSiblingWithSorter() {
-		// no need to test since virtual trees do not support sorting
 	}
 
 	@Ignore("no need to test since virtual trees do not support filtering")
@@ -140,131 +136,76 @@ public void testSorter() {
 	public void testChildIsNotDuplicatedWhenCompareEquals() {
 	}
 
-	// Temporary overrides for bug 347491:
+	// Temporary overrides for bug 347491
 	@Test
 	@Override
 	public void testRefreshWithAddedChildren() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testRefreshWithAddedChildren();
 	}
 
 	@Test
 	@Override
 	public void testDeleteSibling() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testDeleteSibling();
 	}
 
-	@Test
-	@Override
-	public void testExpandToLevel() {
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
-		super.testExpandToLevel();
-	}
-
 	@Test
 	@Override
 	public void testInsertSibling() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testInsertSibling();
 	}
 
 	@Test
 	@Override
 	public void testInsertSiblings() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testInsertSiblings();
 	}
 
 	@Test
 	@Override
 	public void testSetInput() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testSetInput();
 	}
 
 	@Test
 	@Override
 	public void testSomeChildrenChanged() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testSomeChildrenChanged();
 	}
 
 	@Test
 	@Override
 	public void testWorldChanged() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testWorldChanged();
 	}
 
 	@Test
 	@Override
 	public void testContains() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testContains();
 	}
 
 	@Test
 	@Override
 	public void testAutoExpandOnSingleChildThroughEvent() {
-		if (disableTestsBug347491) {
-			return;
-		}
-		if (setDataCalls == 0) {
-			System.err.println("SWT.SetData is not received. Cancelled test " + testName.getMethodName());
-			return;
-		}
+		assumeFalse("test disabled because of bug 347491", disableTestsBug347491);
+		assertTrue("data must have been set", setDataCalls > 0);
 		super.testAutoExpandOnSingleChildThroughEvent();
 	}