[FIXED] How to test Spring @EventListener method?

Issue

I have some event publishing:

@Autowired private final ApplicationEventPublisher publisher;
...
publisher.publishEvent(new MyApplicationEvent(mySource));

I have this event listener:

class MyApplicationEventHandler {

    @Autowired SomeDependency someDependency;

    @EventListener public void processEvent(final MyApplicationEvent event) {
        // handle event...
    }
}

I need to test it using EasyMock. Is there a simple way to publish something in test and assert that my event listener did something?

EDIT:

I tried to create mock test like this:

// testing class
SomeDependency someDependency = mock(SomeDependency.class);

MyApplicationEventHandler tested = new MyApplicationEventHandler(someDependency);

@Autowired private final ApplicationEventPublisher publisher;

@Test
public void test() {
    someDependency.doSomething(anyObject(SomeClass.class));
    replay();
    publisher.publishEvent(new MyApplicationEvent(createMySource()));
}

It didn't work.

java.lang.AssertionError: 
  Expectation failure on verify:
    SomeDependency.doSomething(<any>): expected: 1, actual: 0

Solution

First, As you're using Spring Boot, the testing of these becomes pretty straightforward. This test will spin up the boot context and inject a real instance of ApplicationEventPublisher, but create a mocked instance of SomeDependency. The test publishes the desired event, and verifies that your mock was invoked as you expected.

@RunWith(SpringRunner.class)
@SpringBootTest
public class EventPublisherTest {

   @Autowired 
   private final ApplicationEventPublisher publisher;

   @MockBean
   private SomeDependency someDependency;

   @Test
   public void test() {
      publisher.publishEvent(new MyApplicationEvent(createMySource()));

      // verify that your method in you 
      verify(someDependency, times(1)).someMethod();
   }
}

Answered By - lane.maxwell
Answer Checked By - Marie Seifert (JavaFixing Admin)