使用Mockito进行JVM单元测试以测试Retrofit2和RxJava的网络请求

Question

Android Studio 2.3 RC 1 

我正在使用MVP体系结构并希望运行JVM单元测试。

在我的模型中，我使用Retrofit2和RxJava从API获取电影。我想测试这个函数getPopularMovies(...)但是，这个函数会调用web服务器。但是，在测试中，我想以某种方式模拟这种方式，只是测试onSuccess()和onFailure()方法。

我的模型类看起来像这个片段只是为了保持短：

public class MovieListModelImp implements MovieListModelContract { 

    @Override 
    public void getPopularMovies(PopularMovieResultsListener popularMovieResultsListener) { 
     mSubscription = mMovieAPIService.getPopular(Constants.MOVIES_API_KEY) 
       .subscribeOn(Schedulers.io()) 
       .observeOn(AndroidSchedulers.mainThread()) 
       .subscribe(new Subscriber<Results>() { 
      @Override 
      public void onCompleted() { 
       Timber.d("onCompleted"); 
      } 

      @Override 
      public void onError(Throwable e) { 
       Timber.e(e, "onError"); 
       popularMovieResultsListener.onFailure(e.getMessage()); 
      } 

      @Override 
      public void onNext(Results results) { 
       Timber.d("onNext %d", results.getResults().size()); 
       popularMovieResultsListener.onSuccess(results); 
      } 
     }); 
    } 
} 

和接口：

public interface MovieListModelContract { 
    interface PopularMovieResultsListener { 
     void onFailure(String errorMessage); 
     void onSuccess(Results popularMovies); 
    } 
    void getPopularMovies(PopularMovieResultsListener popularMovieResultsListener); 
} 

我的问题我试图解决的是怎么用的Mockito测试getPopularMovies没有实际调用网络服务？我只是想测试： popularMoviesResultsListener.onFailure(e.getMessage())将被要求未能获得电影 和 popularMovieResultsListener.onSuccess(results);会成功时，电影收到

我有一个这样的测试，但我不知道这是否是正确的被称为：

@Test 
public void shouldDisplaySuccessWhenNetworkSucceeds() { 
    /* Results is the movie results class that is returned */ 
    Results results = new Results(); 

    /* Mock the listener */ 
    MovieListModelContract.PopularMovieResultsListener mockPopularMoviesResultsListener = 
      Mockito.mock(MovieListModelContract.PopularMovieResultsListener.class); 

    /* Real instance of the model */ 
    MovieListModelImp movieListModelImp = new MovieListModelImp(); 

    /* Call getPopularMovies with mock listener - However, this will still make a real network request */ 
    movieListModelImp.getPopularMovies(mockPopularMoviesResultsListener); 

    /* Verify - but I think I have got this all wrong */ 
    verify(mockPopularMoviesResultsListener, times(1)).onSuccess(results); 
} 

所以我的问题是我怎么能嘲笑调用一个网络请求并测试了预期的onSuccess（）和onFailure处（）是否正常工作？

Answer 1

我已成功地完成在这里我的答案。我不确定这是否是最好的方式，希望其他人能够发表评论。

对于设置：

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

    movieListModelContract = new MovieListModelImp(mockMovieAPIService); 

    RxJavaHooks.setOnIOScheduler(new Func1<Scheduler, Scheduler>() { 
     @Override 
     public Scheduler call(Scheduler scheduler) { 
      return Schedulers.immediate(); 
     } 
    }); 

    /* Override RxAndroid schedulers */ 
    final RxAndroidPlugins rxAndroidPlugins = RxAndroidPlugins.getInstance(); 
    rxAndroidPlugins.registerSchedulersHook(new RxAndroidSchedulersHook() { 
     @Override 
     public Scheduler getMainThreadScheduler() { 
      return Schedulers.immediate(); 
     } 
    }); 
} 

而且推倒

@After 
    public void tearDown() throws Exception { 
     RxJavaHooks.reset(); 
     RxAndroidPlugins.getInstance().reset(); 
    } 

我的服务API

@GET("movie/popular") 
Observable<Results> getPopular(@Query("api_key") String apikey); 

嘲笑

@Mock MovieAPIService mockMovieAPIService; 
@Mock Observable<Results> mockCall; 
@Mock ResponseBody responseBody; 
@Mock MovieListModelContract.PopularMovieResultsListener mockPopularMoviesResultsListener; 
private MovieListModelContract movieListModelContract; 
@Captor ArgumentCaptor<Callback<List<Results>>> argumentCaptor; 

我的测试

@Test 
    public void shouldDisplaySuccessMessageOnSuccess() { 
     final Results results = new Results(); 
     when(mockMovieAPIService.getPopular(anyString())).thenReturn(Observable.just(results)); 

     movieListModelContract.getPopularMovies(mockPopularMoviesResultsListener); 

     verify(mockPopularMoviesResultsListener, never()).onFailure(anyString()); 
     verify(mockPopularMoviesResultsListener, times(1)).onSuccess(results); 
    } 

我给出了一个成功案例的例子，它可以作为例子工作。但是，因为一切似乎都很好。我只是想知道有没有更好的方法去做，或者我做了什么错误？

非常感谢提前

Answer 2

这个想法是用户TestSubscriber在单元测试中断言。

返回从改造，而不是可观测空白

（请注意，我已删除的监听PopularMovieResultsListener与您使用RxJava随着RxJava您可以订阅返回的观察到的，使用onNext()，onComplete()， onError()代替。）

public class MovieListModelImp implements MovieListModelContract { 

    @Override 
    public Observable<Results> getPopularMovies() { 
     /** Return the Observable from Retrofit. */ 
     return mMovieAPIService.getPopular(Constants.MOVIES_API_KEY); 
} 

使用在单元测试中TestSubscriber断言

@Mock 
MovieAPIService mMovieAPIService 

@Test 
public void shouldDisplaySuccessWhenNetworkSucceeds() { 

    /* Results is the movie results class that is returned */ 
    Results expectedResults = new Results(); 


    MovieListModelImp movieListModelImp = new MovieListModelImp(); 
    //Mock mMovieAPIService which is the actual network call 
    when(mMovieAPIService.getPopular(any(String.class)).thenReturn(Observable.just(results)); 

    Observable<Results> actualResultsObservable = movieListModelImp.getPopularMovies(); 
    TestObserver<Results> testObserver = actualResultsObservable.test(); 
    testObserver.assertSubscribed(); 

    testObserver.assertResult(expectedResults); 

    //verify 
    verify(mMovieAPIService, times(1)).getPopular(any(String.class)); 

}