Rewrite JobTest#testSetProgressGroup eclipse-platform#1026

The test method JobTest#testSetProgressGroup mixes up at least five test
cases into one method. This makes it hard to comprehend what actually is
tested and to identify the reasons for a failure. This change splits up
the five test cases into separate methods with names reflecting their
purpose and a reduced setup to what is necessary for the test case.
Since the original test method is randomly failing, this change will
make it easier to find the reasons.

Contributes to
eclipse-platform#1026

runtime/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/runtime/jobs/JobTest.java

@@ -1591,13 +1591,70 @@ public void testSetPriority() {
 		}
 	}
 
-	/**
-	 * Tests the API methods Job.setProgressGroup
-	 */
 	@Test
-	public void testSetProgressGroup() {
+	public void testSetProgressGroup_withNullGroup() {
+		assertThrows(RuntimeException.class,
+				() -> new TestJob("testSetProgressGroup_withNullGroup").setProgressGroup(null, 5));
+	}
+
+	@Test
+	public void testSetProgressGroup_withProperGroup() throws InterruptedException {
+		Job job = new TestJob("testSetProgressGroup_withProperGroup") {
+			@Override
+			public IStatus run(IProgressMonitor monitor) {
+				monitor.setCanceled(true);
+				return super.run(monitor);
+			}
+		};
+		IProgressMonitor group = Job.getJobManager().createProgressGroup();
+		group.beginTask("Group task name", 10);
+		job.setProgressGroup(group, 0);
+		job.schedule();
+		job.join();
+		assertThat("job progress has not been reported to group monitor", group.isCanceled());
+		group.done();
+	}
+
+	@Test
+	public void testSetProgressGroup_ignoreWhileWaiting() throws InterruptedException {
+		Job job = new TestJob("testSetProgressGroup_ignoreWhileWaiting") {
+			@Override
+			public IStatus run(IProgressMonitor monitor) {
+				monitor.setCanceled(true);
+				return super.run(monitor);
+			}
+		};
+		IProgressMonitor group = Job.getJobManager().createProgressGroup();
+		job.schedule(10000); // put job to waiting state
+		job.setProgressGroup(group, 0);
+		job.wakeUp();
+		job.join();
+		assertThat("job progress has unexpectedly been reported to group monitor", !group.isCanceled());
+	}
+
+	@Test
+	public void testSetProgressGroup_ignoreWhileRunning() throws InterruptedException {
+		TestBarrier2 barrier = new TestBarrier2();
+		Job job = new TestJob("testSetProgressGroup_ignoreWhileRunning") {
+			@Override
+			public IStatus run(IProgressMonitor monitor) {
+				barrier.upgradeTo(TestBarrier2.STATUS_RUNNING);
+				monitor.setCanceled(true);
+				return super.run(monitor);
+			}
+		};
+		IProgressMonitor group = Job.getJobManager().createProgressGroup();
+		job.schedule();
+		barrier.waitForStatus(TestBarrier2.STATUS_RUNNING);
+		job.setProgressGroup(group, 0);
+		job.join();
+		assertThat("job progress has unexpectedly been reported to group monitor", !group.isCanceled());
+	}
+
+	@Test
+	public void testSetProgressGroup_cancellationPropagatedToMonitor() {
 		final TestBarrier2 barrier = new TestBarrier2();
-		Job job = new Job("testSetProgressGroup") {
+		Job job = new Job("testSetProgressGroup_cancellationStillWorks") {
 			@Override
 			protected IStatus run(IProgressMonitor monitor) {
 				barrier.setStatus(TestBarrier2.STATUS_RUNNING);
@@ -1608,25 +1665,15 @@ protected IStatus run(IProgressMonitor monitor) {
 				return Status.OK_STATUS;
 			}
 		};
-		//null group
-		assertThrows(RuntimeException.class, () -> job.setProgressGroup(null, 5));
 		IProgressMonitor group = Job.getJobManager().createProgressGroup();
-		group.beginTask("Group task name", 10);
-		job.setProgressGroup(group, 5);
-
-		//ignore changes to group while waiting or running
-		job.schedule(100);
 		job.setProgressGroup(group, 0);
-		//wait until job starts and try to set the progress group
+		job.schedule();
 		barrier.waitForStatus(TestBarrier2.STATUS_RUNNING);
-		job.setProgressGroup(group, 0);
-
-		//ensure cancelation still works
 		job.cancel();
 		barrier.setStatus(TestBarrier2.STATUS_WAIT_FOR_DONE);
 		waitForState(job, Job.NONE);
-		assertEquals("1.0", IStatus.CANCEL, job.getResult().getSeverity());
-		group.done();
+		assertThat("job progress has not been reported to group monitor", group.isCanceled());
+		assertEquals("job was unexpectedly not canceled", IStatus.CANCEL, job.getResult().getSeverity());
 	}
 
 	@Test