android - 如何使用 Mockito 测试 Presenter 中的 void 方法？

Question

我有一个使用 MVP 模式构建的非常简单的应用程序。这是我的契约(Contract):

public interface CitiesContract {
    interface View {
        void addCitiesToList(List<City> cityList);
    }

    interface Presenter {
        void getCityList();
    }

    interface Model {
        List<City> getCityList();
    }
}

这是我的观点:

public class CitiesActivity extends AppCompatActivity implements CitiesContract.View {
    private List<City> cityList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cities);

        CitiesPresenter presenter = new CitiesPresenter(this);
        presenter.getCityList();
    }

    @Override
    public void addCitiesToList(List<City> cities) {
        cityList.addAll(cities);
    }
}

这是我的演示者:

public class CitiesPresenter implements CitiesContract.Presenter {
    private CitiesContract.View view;
    private CitiesModel model;

    public CitiesPresenter(CitiesContract.View view) {
        this.view = view;
        model = new CitiesModel();
    }

    @Override
    public void getCityList() {
        List<City> cityList = model.getCityList();
        view.addCitiesToList(cityList);
    }
}

这是我的模型:

public class CitiesModel implements CitiesContract.Model {
    @Override
    public List<City> getCityList() {
        List<City> cityList = new ArrayList<>();
        //Add 30 cities to the list
        return cityList;
    }
}

如何在 Presenter 中测试 getCityList() 方法？到目前为止，这是我尝试过的:

public class CitiesPresenterTest {
    private CitiesContract.Presenter citiesPresenter;
    @Mock
    private CitiesContract.View citiesView;

    public void setUp() {
        MockitoAnnotations.initMocks(this);
        citiesPresenter = new CitiesPresenter(citiesView);
    }

    @Test
    public void getCityListTest() {
        citiesPresenter.getCityList();
        //What to do next???
    }
}

Answer 1

好的，顺便说一句，这是个好问题。首先，您还需要模拟您的模型。第二:安排一些事情:例如 model.getCityList() 返回 null。之后，您可以使用 mockitos verify 运算符进行验证。示例:

when(model.getCityList()).thenReturn(null);
citiesPresenter.getCityList();
verify(view).addCitiesToList(null);

另一种情况可能与此类似，但列表为空:

List<City> citiesList = new ArrayList<>();

when(model.getCityList()).thenReturn(citiesList );
citiesPresenter.getCityList();
verify(view).addCitiesToList(citiesList);

另一个可以是这样，你可以自己构建一个假列表来测试它:

List<City> citiesList = new ArrayList<>();
list.add(City("name", "something else", "i don't know what atributes you have"));

when(model.getCityList()).thenReturn(citiesList );
citiesPresenter.getCityList();
verify(view).addCitiesToList(citiesList);

希望我有所帮助。

附加信息:当进行单元测试时，您的脑海中应该有 3 个基本步骤:首先，您安排:因此您创建自己的场景。例如，如果列表为空会怎样。第二:你行动:这一步是你测试你想要的方法的地方。第三:断言:这是您验证或断言您的期望与给定代码匹配的地方。