Mockito.verifyCompletion for spies in an asynchronous environment.

I’m writing a component test (not a unit test) against some code which is doing some asynchronous processing. In the test, I want to wait until a function is called, before checking that the state it creates is created correctly. Currently it is possible to wait until a spy is called, but it is not possible to wait until that call completes.

This is not a bug. I already have a workaround, so it’s a low-priority feature wish:

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT
        classes = {TestConfiguration.class})
public class TestPublish {
  //...
  @SpyBean PublisherService spy;

  @Test
  public void shouldRetryBeatPublishIfFirstAttemptFails() throws InterruptedException {
    //...
    Mockito.verify(spy, Mockito.timeout(10_000).atLeast(3)).checkForPublish(eq(expected));

    //Check that state created is correct.
  }
}

One possible api would be to add a Mockito.verifyCompletion Another possible api would be to add a Mockito.timeoutToCompletion

Anyways: I’ve been quite happy with being able to do timeout at all, and spies are basically heaven sent, so thank you.

Best Regards, Myrle

Edit by Mockito dev: put Java code in a snippet for syntax highlighting

[AlexeiZenin]

Definitely would be useful to have this part of the Mockito library as a timeoutTillCompletion() style method with verify(). Please review this again and look at HadarLevi’s push above.

[lhannest]

Bump for this issue. I’ve found the same workaround, with a utility method:

public static org.mockito.stubbing.Stubber countDown(CountDownLatch latch) {
    return org.mockito.Mockito.doAnswer(i -> {
        try {
            return i.callRealMethod();
        } finally {
            latch.countDown();
        }
    });
}

CountDownLatch latch = new CountDownLatch(1);

countDown(latch).when(mock).methodCall();

latch.await();

But a one-line Mockito.verifyCompletion with timeout parameters would be much more attractive.