android - 使用 mockito 和事件监听器进行单元测试 MVP

Question

Android Studio 2.1.2

我想测试是否确实调用了 LoginModelImp 中的回调 onUsernameError、onPasswordError 和 onSuccess。我不确定如何测试事件监听器。但是，测试失败，因为这些函数从未被调用过。我正在用 mockito mock 他们并试图验证他们。

到目前为止，这是我的代码。

演示者界面

public interface LoginPresenterContract<LoginFragmentViewContract> {
    void validateCredentials();

    void attachView(LoginFragmentViewContract view);
    void detachView();
}

Presenter 实现

public class LoginPresenterImp implements LoginPresenterContract<LoginFragmentViewContract>, LoginModelContract.OnLoginCompletedListener {

    private LoginModelContract mLoginModelContract;
    private LoginFragmentViewContract mLoginFragmentView;

    public LoginPresenterImp(LoginModelContract loginModelContract) {
        mLoginModelContract = loginModelContract;
    }

    /*
     * LoginPresenterContact - implementation
     */
    @Override
    public void attachView(LoginFragmentViewContract view) {
        mLoginFragmentView = view;
    }

    @Override
    public void detachView() {
        mLoginFragmentView = null;
    }

    @Override
    public void validateCredentials() {
        if(mLoginModelContract != null) {
            mLoginModelContract.login(
                    mLoginFragmentView.getUsername(),
                    mLoginFragmentView.getPassword(),
                    LoginPresenterImp.this);
        }
    }

    /*
     * LoginModelContract.OnLoginCompletedListener - implementation
     */
    @Override
    public void onUsernameError() {
        if(mLoginFragmentView != null) {
            mLoginFragmentView.onLoginFailed("Incorrect username");
        }
    }

    @Override
    public void onPasswordError() {
        if(mLoginFragmentView != null) {
            mLoginFragmentView.onLoginFailed("Incorrect password");
        }
    }

    @Override
    public void onSuccess() {
        if(mLoginFragmentView != null) {
            mLoginFragmentView.onLoginSuccess();
        }
    }
}

模型界面

public interface LoginModelContract {
    interface OnLoginCompletedListener {
        void onUsernameError();
        void onPasswordError();
        void onSuccess();
    }
    void login(String username, String password, OnLoginCompletedListener onLoginCompletedListener);
}

模型实现

public class LoginModelImp implements LoginModelContract {
    /* Testing Valid username and passwords */
    private static String validUsername = "steve";
    private static String validPassword = "1234";

    @Override
    public void login(final String username,
                      final String password,
                      final OnLoginCompletedListener onLoginCompletedListener) {

        boolean hasSuccess = true;
        if(TextUtils.isEmpty(username) || !username.equals(validUsername)) {
        /* TEST onUsernameError() */
            onLoginCompletedListener.onUsernameError();
            hasSuccess = false;
        }

        if(TextUtils.isEmpty(password) || !password.equals(validPassword)) {
        /* TEST onPasswordError() */
            onLoginCompletedListener.onPasswordError();
            hasSuccess = false;
        }

        if(hasSuccess) {
        /* TEST onSuccess() */
            onLoginCompletedListener.onSuccess();
        }
    }
}

使用 Mockito 进行 JUnit4 测试

public class LoginPresenterImpTest {
    private LoginFragmentViewContract mMockViewContract;
    private LoginModelContract mMockModelContract;
    private LoginModelContract.OnLoginCompletedListener mMockOnLoginCompletedListener;
    private LoginPresenterContract<LoginFragmentViewContract> mLoginPresenterContract;

    @Before
    public void setUp() throws Exception {
        mMockViewContract = Mockito.mock(LoginFragmentViewContract.class);
        mMockModelContract = Mockito.mock(LoginModelContract.class);
        mMockOnLoginCompletedListener = Mockito.mock(LoginModelContract.OnLoginCompletedListener.class);
        mLoginPresenterContract = new LoginPresenterImp(mMockModelContract);
        mLoginPresenterContract.attachView(mMockViewContract);
    }

    @Test
    public void shouldSuccessWithValidCredentials() {
        when(mMockViewContract.getUsername()).thenReturn("steve");
        when(mMockViewContract.getPassword()).thenReturn("1234");

        mLoginPresenterContract.validateCredentials();

        verify(mMockViewContract, times(1)).getUsername();
        verify(mMockViewContract, times(1)).getPassword();

        verify(mMockOnLoginCompletedListener, times(1)).onSuccess();

        verify(mMockOnLoginCompletedListener, never()).onPasswordError();
        verify(mMockOnLoginCompletedListener, never()).onUsernameError();
    }
}

有什么方法可以测试这个实现吗？

非常感谢您的任何建议，

Answer 1

测试类 LoginPresenterImpTest 是关于 LoginPresenterImp 类的测试，它应该只使用它的实际实现和它的合作者的模拟。 LoginModelContract.OnLoginCompletedListener 类是 LoginModelImp 的协作者，因此在 LoginPresenterImp 的精心设计的纯单元测试中，就像您的一样，它是它从未被调用是完全正常的。我建议的解决方案是单独测试 LoginModelImp:

public class LoginModelImpTest {

    private LoginModelContract.OnLoginCompletedListener mMockOnLoginCompletedListener;
    private LoginModelImp loginModelImp;

    @Before
    public void setUp() throws Exception {
        mMockOnLoginCompletedListener = Mockito.mock(LoginModelContract.OnLoginCompletedListener.class);
        loginModelImp = new LoginModelImp();
    }

    @Test
    public void shouldSuccessWithValidCredentials() {

        loginModelImp.login("steve", "1234", mMockOnLoginCompletedListener);;

        verify(mMockOnLoginCompletedListener, times(1)).onSuccess();

        verify(mMockOnLoginCompletedListener, never()).onPasswordError();
        verify(mMockOnLoginCompletedListener, never()).onUsernameError();
    }
}

或者，您必须在 LoginPresenterImpTest 中使用 LoginModelImp 的实际实现并监视您的监听器(即演示器本身)或配置模拟以进行他们调用听众。这是一个示例，但我不会使用这个示例:

public class LoginPresenterImpTest {
    private LoginFragmentViewContract mMockViewContract;
    private LoginModelContract mModelContract;
    private LoginModelContract.OnLoginCompletedListener mMockOnLoginCompletedListener;
    private LoginPresenterContract<LoginFragmentViewContract> mLoginPresenterContract;

    @Before
    public void setUp() throws Exception {
        mMockViewContract = Mockito.mock(LoginFragmentViewContract.class);
        mModelContract = new LoginModelImp();
        LoginPresenterImp spyPresenterImp = Mockito.spy(new LoginPresenterImp(mModelContract));
        mLoginPresenterContract = spyPresenterImp;
        mMockOnLoginCompletedListener = spyPresenterImp;
        mLoginPresenterContract.attachView(mMockViewContract);
    }

    @Test
    public void shouldSuccessWithValidCredentials() {
        when(mMockViewContract.getUsername()).thenReturn("steve");
        when(mMockViewContract.getPassword()).thenReturn("1234");

        mLoginPresenterContract.validateCredentials();

        verify(mMockViewContract, times(1)).getUsername();
        verify(mMockViewContract, times(1)).getPassword();

        verify(mMockOnLoginCompletedListener, times(1)).onSuccess();

        verify(mMockOnLoginCompletedListener, never()).onPasswordError();
        verify(mMockOnLoginCompletedListener, never()).onUsernameError();
    }
}