如何从不使用Mockito模拟对象来测试异步方法？

Question

I want to test the code below with Mockito

@Override
public void getSessionList(final int carId, final ResultCallback<List<Session>> callback) {
    jobExecutor.execute(new Runnable() {
        @Override
        public void run() {
            List<SessionEntity> sessions = IDataStore.getSessionList(carId);
            final List<Session> sessionList = new ArrayList<>();
            if (sessions != null) {
                for (SessionEntity entity : sessions) {
                    sessionList.add(mapper.transform(entity));
                }
                uiThread.post(new Runnable() {
                    @Override
                    public void run() {
                        if (callback != null) {
                            callback.onResult(sessionList);
                        }
                    }
                });
            } 
        }
    });
}

I tried to do something like this, but my verify methods will be executed early than runnable. Thread.sleep() works well for the first two verify, but how to test the result from callback.onResult which will be executed in the main thread?

private Repository repository // not mocked
@Mock
private IDataStore dataStore;
@Mock
private DataToDomainMapper dataToDomainMapper;
@Mock
private ResultCallback resultCallback;

@Test
public void testGetSessionListCallbackSuccess(){
    List<SessionEntity> sessionEntities = Arrays.asList(sessionEntity, sessionEntity, sessionEntity);

    given(dataStore.getSessionList(anyInt())).willReturn(sessionEntities);
    given(dataToDomainMapper.transform(any(SessionEntity.class))).willReturn(session);

    repository.getSessionList(1, resultCallback);

    verify(dataStore).getSessionList(anyInt());
    verify(dataToDomainMapper, times(3)).transform(any(SessionEntity.class));
    verify(resultCallback).onResult(any(List.class));
}

Answer 1

Check out tool for testing async methods called Awaitility . Very handy tool, saved me a lot of time on testing async methods.

Answer 2

我相信您可以将匿名Runnable移至内部（或嵌套）类并在两部分进行拆分测试：检查jobExecutor是否开始使用相应的类实例执行；以及检查内部/嵌套类的run（）方法是否按预期工作