在Android中的MVP演示者中对RxJava进行单元测试

Question

我是TDD的新手。也是MVP和Rxjava的新手。我只是潜入它，这是值得的。但我坚持在测试部分。我理解单元测试的基础。这对我来说有点困难。但我坚持到这里，那么如何测试主持人呢？

这是Presenter类 -

public class NewsPresenter {

private final RxjavaService service;
private final MainView view;
private CompositeSubscription subscriptions;

public NewsPresenter(RxjavaService service, MainView view) {
    this.service = service;
    this.view = view;
    subscriptions = new CompositeSubscription();
}

public void getNewsList(String urlQ){
    view.showWait();

    Subscription subscription = service.getNews(urlQ ,new RxjavaService.GetNewsCallback() {
        @Override
        public void onSuccess(Articles articles) {
            view.removeWait();
            view.getNewsListSuccess(articles);
        }

        @Override
        public void onError(NetworkError networkError) {
            view.removeWait();
            view.onFailure(networkError.getAppErrorMessage());
            Log.i("huh",networkError.getMessage());
        }
    });

    subscriptions.add(subscription);
}

public void onStop(){
    subscriptions.unsubscribe();
}

}

这是视图界面 -

public interface MainView {

void showWait();

void removeWait();

void onFailure(String appErrorMessage);

void getNewsListSuccess(Articles articles);

}

这是RxJavaService类 -

public class RxjavaService {

private final NewsRestService newsRestService;

public RxjavaService(NewsRestService newsRestService) {
    this.newsRestService = newsRestService;
}


public interface GetNewsCallback {
    void onSuccess(Articles articles);

    void onError(NetworkError networkError);
}


public Subscription getNews(String q, final GetNewsCallback getNewsCallback) {
    Log.i("stuck","service called");
    return newsRestService.getNewsBySearch(q,"8dca7dea475e41e49518b2c61131e118",100)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .onErrorResumeNext(new Func1<Throwable, Observable<? extends Articles>>() {
                @Override
                public Observable<? extends Articles> call(Throwable throwable) {
                    return Observable.error(throwable);
                }
            })
            .subscribe(new Subscriber<Articles>() {
                @Override
                public void onCompleted() {
                    Log.i("stuck","complete");
                }

                @Override
                public void onError(Throwable e) {
                    getNewsCallback.onError(new NetworkError(e));
                    Log.i("stuck",e.getMessage());
                }

                @Override
                public void onNext(Articles articles) {
                    getNewsCallback.onSuccess(articles);
                    Log.i("stuck","Onnext");
                }
            });
}

}

这是我被困的测试课 -

@RunWith(MockitoJUnitRunner.class)

public class NewsListTest {

private NewsPresenter newsPresenter;

@Mock
private RxjavaService rxjavaService;
@Mock
private MainView mainView;

@Before
public void setUp() throws Exception {
    MockitoAnnotations.initMocks(this);

    newsPresenter = new NewsPresenter(rxjavaService,mainView);
}

@After
public void tearDown() throws Exception {
    mainView = null;
    newsPresenter.onStop();
}

@Test
public void Testing_The_Result() {

}

}

Answer 1

首先是

1. 如果你进入TDD，你永远不会陷入你描述的情况。在TDD中，您启动，测试失败，然后再编写实现。所以你的问题更多的是测试TDD。
2. 我建议切换到RxJava2，因为RxJava1将于3月31日到达End of Life。
3. 我很奇怪RxJavaService将API从发布/订阅更改为回调。为什么不坚持使用rx API一直到演示者？

使用模拟的RxJavaService进行测试

如果您希望使用测试中的设置完成测试，则看起来像这样：

@Test
public void Testing_The_Result() {
    final RxjavaService.GetNewsCallback[] callback = new RxjavaService.GetNewsCallback[1];
    Mockito.when(rxjavaService.getNews(ArgumentMatchers.anyString(), ArgumentMatchers.any(RxjavaService.GetNewsCallback.class))).thenAnswer(new Answer<Subscription>() {
        public Subscription answer(InvocationOnMock invocationOnMock) {
            callback[0] = invocationOnMock.getArgument(1);
            return mock(Subscription.class);
        }
    });
    newsPresenter.getNewsList("some url");
    Articles articles = new Articles();

    callback[0].onSuccess(articles);

    verify(mainView).removeWait();
    verify(mainView).getNewsListSuccess(articles);
}

你可以通过不使用Mockito模拟RxJavaService来摆脱丑陋的代码，而是滚动你自己的手写模拟，它会存储回调并将其提供给测试。

但是，我建议采用不同的方法。

使用真实的RxJavaService进行测试并模拟NewsRestService

如果我们只嘲笑NewsRestService，我会说它更有意义并提供更好的测试：

@RunWith(MockitoJUnitRunner.class)
public class NewsList2Test {

    private NewsPresenter newsPresenter;

    @Mock
    private MainView mainView;
    @Mock
    private NewsRestService newsRestService;

    @Before
    public void setUp() {
        newsPresenter = new NewsPresenter(new RxjavaService(newsRestService), mainView);
    }

    @Test
    public void show_success_in_view_when_there_are_articles() {
        when(newsRestService.getNewsBySearch(eq("some url"), anyString(), anyInt()))
                .thenReturn(Observable.just(new Articles()));

        newsPresenter.getNewsList("some url");

        verify(mainView).removeWait();
        verify(mainView).getNewsListSuccess(any(Articles.class));
    }

}