Async Method Junit Test

When making junit test, it's hard to test async method.
I introduce the way to test async method by changing async to sync task executor.

@Service
@Slf4j
public class TestServiceImpl implements TestService {

    @Autowired
    private RestTemplate restTemplate;

    @Override
    @Async
    public void getString() {

        log.info("start");
        restTemplate.getForEntity("http://www.test.com", String.class);
    }
}

We will test this async method as above.

@RunWith(SpringRunner.class)
@SpringBootTest
@Slf4j
public class TestServiceTest {

    @Configuration
    @Import(AsyncTestApplication.class)
    static class ContextConfiguration {
        @Bean
        @Primary
        public Executor executor() {
            return new SyncTaskExecutor();
        }
    }

    @Autowired
    private TestService testService;

    @MockBean
    private RestTemplate restTemplate;

    @Test
    public void testGetString() {

        //given
        given(restTemplate.getForEntity(anyString(), eq(String.class))).willReturn(new ResponseEntity(HttpStatus.OK));

        //when
        testService.getString();

        //then
        verify(restTemplate, times(1)).getForEntity(anyString(), eq(String.class));
    }
}

By using Configuration annotation, you can set the junit test config.
I will change the asyncExecutor to syncTaskExecutor,so that we could check the internal logic of async method.

2018-03-01 15:54:47.729  INFO 6836 --- [           main] o.b.test.service.impl.TestServiceImpl    : start

You can find your test case passed.


You can download whole project from below git url.

https://gitlab.com/shashaka/async-junit-test-project