Make completion proposal calculation test time-independent #906 #907

The test cases for completion proposals in CompletionTest depend on
specific timing behavior of a test proposal processor. On one hand, this
is prone to errors if proper timing is not given on the test
environment. On the other hand, the tests run unnecessarily long because
of waiting long enough.

This change replaces the fixed-time waiting of the
LongRunningBarContentAssistProcessor with an explicit trigger that
finalizes the content calculation as soon as some barrier is reached
within the tests.

Contributes to
#906 and
#907

Author: HeikoKlare

tests/org.eclipse.ui.genericeditor.tests/src/org/eclipse/ui/genericeditor/tests/CompletionTest.java

@@ -170,20 +170,22 @@ private void checkCompletionContent(final Table completionProposalList) {
 			protected boolean condition() {
 				return completionProposalList.getItemCount() == 2;
 			}
-		}.waitForCondition(completionProposalList.getDisplay(), 200));
+		}.waitForCondition(completionProposalList.getDisplay(), 5000));
 		final TableItem computingItem = completionProposalList.getItem(0);
 		assertTrue("Missing computing info entry", computingItem.getText().contains("Computing")); //$NON-NLS-1$ //$NON-NLS-2$
 		TableItem completionProposalItem = completionProposalList.getItem(1);
 		final ICompletionProposal selectedProposal = (ICompletionProposal)completionProposalItem.getData();
 		assertTrue("Incorrect proposal content", BarContentAssistProcessor.PROPOSAL.endsWith(selectedProposal .getDisplayString()));
 		completionProposalList.setSelection(completionProposalItem);
+		
+		LongRunningBarContentAssistProcessor.finishComputation();
 		// asynchronous
 		new DisplayHelper() {
 			@Override
 			protected boolean condition() {
 				return completionProposalList.getItem(0) != computingItem && completionProposalList.getItemCount() == 2;
 			}
-		}.waitForCondition(completionProposalList.getDisplay(), LongRunningBarContentAssistProcessor.DELAY + 200);
+		}.waitForCondition(completionProposalList.getDisplay(), 5000);
 		completionProposalItem = completionProposalList.getItem(0);
 		assertTrue("Proposal content seems incorrect", BarContentAssistProcessor.PROPOSAL.endsWith(((ICompletionProposal)completionProposalItem.getData()).getDisplayString()));
 		TableItem otherProposalItem = completionProposalList.getItem(1);
@@ -223,15 +225,15 @@ protected boolean condition() {
 		emulatePressLeftArrowKey();
 		DisplayHelper.sleep(editor.getSite().getShell().getDisplay(), 200); //give time to process events
 		long processingDuration = System.currentTimeMillis() - timestamp;
-		assertTrue("UI Thread frozen for " + processingDuration + "ms", processingDuration < LongRunningBarContentAssistProcessor.DELAY);
+		assertTrue("UI Thread frozen for " + processingDuration + "ms", processingDuration < LongRunningBarContentAssistProcessor.TIMEOUT_MSEC);
 	}
 
 	@Test
 	public void testMoveCaretBackUsesAllProcessors_bug522255() throws Exception {
 		testCompletion();
 		emulatePressLeftArrowKey();
 		final Set<Shell> beforeShells = Arrays.stream(editor.getSite().getShell().getDisplay().getShells()).filter(Shell::isVisible).collect(Collectors.toSet());
-		DisplayHelper.sleep(editor.getSite().getShell().getDisplay(), LongRunningBarContentAssistProcessor.DELAY + 500); // adding delay is a workaround for bug521484, use only 100ms without the bug
+		DisplayHelper.sleep(editor.getSite().getShell().getDisplay(), 200);
 		this.completionShell= findNewShell(beforeShells, editor.getSite().getShell().getDisplay(), true);
 		final Table completionProposalList = findCompletionSelectionControl(this.completionShell);
 		assertEquals("Missing proposals from a Processor", 2, completionProposalList.getItemCount()); // replace with line below when #5214894 is done

tests/org.eclipse.ui.genericeditor.tests/src/org/eclipse/ui/genericeditor/tests/contributions/LongRunningBarContentAssistProcessor.java

@@ -13,26 +13,38 @@
  *******************************************************************************/
 package org.eclipse.ui.genericeditor.tests.contributions;
 
+import static org.junit.Assert.assertFalse;
+
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 
 public class LongRunningBarContentAssistProcessor extends BarContentAssistProcessor {
 
 	public static final String PROPOSAL = "bars are also good for soft drink cocktails.";
-	public static final int DELAY = 2000;
-
+	public static final int TIMEOUT_MSEC = 10_000;
+	private static boolean shouldComputationFinish = false;
+	
 	public LongRunningBarContentAssistProcessor() {
 		super(PROPOSAL);
 	}
 
 	@Override
 	public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
 		try {
-			Thread.sleep(DELAY);
+			long startExecutionTime = System.currentTimeMillis();
+			while (!shouldComputationFinish && (System.currentTimeMillis() - startExecutionTime) < TIMEOUT_MSEC) {
+				Thread.sleep(20);
+			}
 		} catch (InterruptedException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
+			// Just finish on unexpected interrupt
 		}
+		shouldComputationFinish = false;
 		return super.computeCompletionProposals(viewer, offset);
 	}
+	
+	public static void finishComputation() {
+		assertFalse("Concurrent requests for finishing computation of long running content assist processor", shouldComputationFinish);
+		shouldComputationFinish = true;
+	}
+	
 }