使用Mockito進行JVM單元測試以測試Retrofit2和RxJava的網絡請求

Question

Android Studio 2.3 RC 1 

我正在使用MVP體系結構並希望運行JVM單元測試。

在我的模型中，我使用Retrofit2和RxJava從API獲取電影。我想測試這個函數getPopularMovies(...)但是，這個函數會調用web服務器。但是，在測試中，我想以某種方式模擬這種方式，只是測試onSuccess()和onFailure()方法。

我的模型類看起來像這個片段只是爲了保持短：

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); 
} 

我的問題我試圖解決的是怎麼用的Mockito測試getPopularMovies沒有實際調用網絡服務？我只是想測試： popularMoviesResultsListener.onFailure(e.getMessage())將被要求未能獲得電影 和 popularMovieResultsListener.onSuccess(results);會成功時，電影收到

我有一個這樣的測試，但我不知道這是否是正確的被稱爲：

@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); 
} 

所以我的問題是我怎麼能嘲笑調用一個網絡請求並測試了預期的onSuccess（）和onFailure處（）是否正常工作？

Answer 1

我已成功地完成在這裏我的答案。我不確定這是否是最好的方式，希望其他人能夠發表評論。

對於設置：

@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(); 
    } 

我的服務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; 

我的測試

@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); 
    } 

我給出了一個成功案例的例子，它可以作爲例子工作。但是，因爲一切似乎都很好。我只是想知道有沒有更好的方法去做，或者我做了什麼錯誤？

非常感謝提前

Answer 2

這個想法是用戶TestSubscriber在單元測試中斷言。

返回從改造，而不是可觀測空白

（請注意，我已刪除的監聽PopularMovieResultsListener與您使用RxJava隨着RxJava您可以訂閱返回的觀察到的，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); 
} 

使用在單元測試中TestSubscriber斷言

@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)); 

}