Android Mocking Dagger2为Espresso测试注入依赖项

Question

我有一个严重依赖注入(dagger2)应用程序.我想在没有测试导航整个应用程序的情况下运行espresso测试,并登录到应用程序.

我想从我的teleActivity开始,并模拟登录管理器.但是在任何@test函数中,我们已经调用了空指针,因为我们调用了onCreate.如果我在启动活动之前覆盖它(如下所示),则活动为空.

根据我的理解,切换下划线依赖关系的能力是我们使用Dagger2的一个重要原因,否则它只是一个非常过度设计的单例.如何覆盖,模拟或切换注射到测试匕首模块 - 所以我可以创建这个简单的浓咖啡测试.

注意我还在MVP设计模式中写了所有这些,如果这有所不同.

TeleActivity

@Inject
TelePresenter mTelePresenter;
@Inject
public LoginStateManager mLoginStateManager;

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ButterKnife.bind(this);
    DaggerInjectorTele.get().inject(this);
    mTelePresenter.setTeleDependencies(this);
    Intent intent = getIntent();

    String searchId = null;

    if (intent != null) {
        searchId = intent.getStringExtra(Constants.SEARCH_ID);
       }

    mTelePresenter.onCreateEvent(searchId,
            Helper.makeAuthorizationHeader(
            // CRASH Null pointer
            mLoginStateManager.getBaseLoginResponse().getAccessToken()));

}

浓咖啡

@LargeTest
@RunWith(AndroidJUnit4.class)
public class TeleTest {
    @Rule
    public ActivityTestRule<TeleActivity> mActivityTestRule = new ActivityTestRule(
            TeleActivity.class) {
        @Override
        protected void beforeActivityLaunched() {
            super.beforeActivityLaunched();
            TeleActivity teleActivity = (TeleActivity)getActivity();
             //teleActivity NULL!
            teleActivity.mLoginStateManager = mock(LoginStateManager.class);
            LoginResponse loginResponse = mock(LoginResponse.class);
            when(loginResponse.getAccessToken()).thenReturn("1234");
            // Nope here still null


when(teleActivity.mLoginStateManager.getBaseLoginResponse()).thenReturn(loginResponse);

        }
    };

匕首注射器

  public class DaggerInjectorTele {
    private static TelePresenterComponent telePresenterComponent =
            DaggerTelePresenterComponent.builder().build();

    public static TelePresenterComponent get() {
        return telePresenterComponent;
    }
}

TelePresenterComponent

@Singleton
@Component(modules = {TelePresenterModule.class,
        LoginStateManagerModule.class})
public interface TelePresenterComponent {
    void inject(TeleActivity activity);
}

TelePresenterModule

@Module
public class TelePresenterModule {

    @Provides
    @Singleton
    public TelePresenter getTelePresenter() {
        return new TelePresenter();
    }
}

LoginStateManagerModule

@Module
public class LoginStateManagerModule {

    @Provides
    @Singleton
    public LoginStateManager getLoginStateManager(){
        return new LoginStateManager();
    }
}

Answer 1

首先,您决定使用依赖注入(Dagger2)是一个非常好的决定,确实会使您的测试更容易编写.

您必须覆盖依赖注入配置(模块)并注入模拟.这是一个如何完成它的简单例子.

首先你需要一个模拟:

LoginStateManager lsmMock = mock(LoginStateManager.class);

现在覆盖DI配置以使用此模拟:

//Extend your TelePresenterModule, override provider method
public class TestTelePresenterModule extends TelePresenterModule{
    @Override
    public LoginStateManager getLoginStateManager() {
        //simply return the mock here
        return lsmMock;
    }
}

现在来测试一下:

@Test
//this is an espresso test
public void withAMock() {
    //build a new Dagger2 component using the test override
    TelePresenterComponent componentWithOverride = DaggerTelePresenterComponent.builder()
            //mind the Test in the class name, see a class above
            .telePresenterModule(new TestTelePresenterModule())
            .build();

    //now we initialize the dependency injector with this new config
    DaggerInjectorTele.set(componentWithOverride);

    mActivityRule.launchActivity(null);

    //verify that injected mock was interacted with
    verify(lsmMock).whatever();
}

示例来自:https://github.com/yuriykulikov/DIComparison/blob/master/app/src/androidTest/java/com/example/yuriy/dependencyinjectioncomparison/Dagger2Test.java