How to test Spring @EventListener method?

Question

I have some event publishing:

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


        

Answer 1

The option I took was to create a TestConfiguration and a listener within the test itself like this:

@Slf4j
@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = {RegistrationConfiguration.class, RegistrationTestConfiguration.class})
class RegistrationServiceIntegrationTest {

    @Autowired
    private DynamoDBMapper dynamoDBMapper;
    @Autowired
    private AmazonDynamoDBAsync amazonDynamoDB;
    @Autowired
    private RegistrationRepository repository;
    @Autowired
    private ApplicationEventPublisher eventPublisher;

    private String personaId;

    private RegistrationService testObj = null;

    @BeforeEach void setup() {
        RegistrationServiceDBHelper.initializeTable(dynamoDBMapper, amazonDynamoDB, repository);
        personaId = UUID.randomUUID().toString();
        testObj = new RegistrationService(repository, eventPublisher);
    }


    @TestConfiguration
    static class RegistrationTestConfiguration {
        @Bean
        RegistrationServiceEventListener eventListener() {
            return new RegistrationServiceEventListener();
        }
    }


    @Component
    public static class RegistrationServiceEventListener {
        @TransactionalEventListener
        public void onPlayerRegisteredEvent(PlayerRegisteredEvent event) {
            log.info("Received new user event {}", event.personaId());
            assertThat(event.personaId()).isNotBlank();
        }
    }


    @DisplayName("given a persona id that is not registered")
    @Nested class WhenNoPlayerIsRegistered {

        @DisplayName("when a player is registered"
                + " then an event is raised")
        @Test void raisePlayerRegisteredEvent() {
            // When
            testObj.registerPlayer(personaId);
        }
    }
}