@Test
public void shouldPeriodicallyProcessQueue() throws Exception {
NotificationQueueElement queueElement = mock(NotificationQueueElement.class);
Notification notification = mock(Notification.class);
when(queueElement.getNotification()).thenReturn(notification);
when(manager.getFromQueue())
.thenReturn(queueElement)
.thenReturn(null)
.thenReturn(queueElement)
.thenReturn(null)
.thenReturn(queueElement)
.thenReturn(null);
doNothing().when(service).deliver(any(Notification.class));
service.start();
Thread.sleep(1500); // sleep 1.5 second to process queue
service.stop();
verify(service, times(3))
.deliver(notification); // 3 times - 1 on start, 1 after delay, 1 on stop
}
