为什么在为redux操作运行test时调用了__mock__文件夹？

Question

我在redux操作中调用react-navigation NavigationService。测试我需要模拟导航功能的操作。

/app/utils/NavigationService.js

import { NavigationActions } from 'react-navigation';

let navigator;

function setTopLevelNavigator(navigatorRef) {
  navigator = navigatorRef;
}

function navigate(routeName, params) {
  navigator.dispatch(NavigationActions.navigate({
    type: NavigationActions.NAVIGATE,
    routeName,
    params,
  }));
}

// add other navigation functions that you need and export them

export default {
  navigate,
  setTopLevelNavigator,
};

我创建了一个紧邻NavigationService.js文件的__mock__文件夹。

app/utils/__mocks__/NavigationService.js更新

const navigate = jest.fn();
const setTopLevelNavigator = jest.fn();

export default {
    navigate,
    setTopLevelNavigator,
};

为什么在测试运行时jest自动模拟navigate函数？ https://jestjs.io/docs/en/manual-mocks

__tests__/actions/AuthActions.test.js更新

jest.mock('../../app/utils/NavigationService'); //at the top directly behind other imports

it('should call firebase on signIn', () => {
    const user = {
      email: '[email protected]',
      password: 'sign',
    };

    const expected = [
      { type: types.LOGIN_USER },
      { payload: 1, type: types.DB_VERSION },
      { payload: 'prod', type: types.USER_TYPE },
      { payload: { name: 'data' }, type: types.WEEKPLAN_FETCH_SUCCESS },
      { payload: { name: 'data' }, type: types.RECIPELIBRARY_FETCH_SUCCESS },
      {
        payload: { user: { name: 'user' }, userVersionAndType: { dbVersion: 1, userType: 'prod' } },
        type: types.LOGIN_USER_SUCCESS,
      },
    ];

    return store.dispatch(actions.loginUser(user)).then(() => {
      expect(store.getActions()).toEqual(expected);
    });
  });

app/actions/AuthActions.js

export const loginUser = ({ email, password }) => (dispatch) => {
  dispatch({ type: LOGIN_USER });
  return firebase
    .auth()
    .signInWithEmailAndPassword(email, password)
    .catch((signInError) => {
      dispatch({ type: CREATE_USER, payload: signInError.message });
      return firebase
        .auth()
        .createUserWithEmailAndPassword(email, password)
        .then(async (user) => {
          const userVersionAndType = await dispatch(initUser());
          await dispatch(initWeekplan(userVersionAndType));
          await dispatch(initRecipeLibrary(userVersionAndType));
          return user;
        });
    })
    .then(async (user) => {
      saveCredentials(email, password);
      const userVersionAndType = await dispatch(getUserVersionAndType());
      await dispatch(weekplanFetch(userVersionAndType));
      await dispatch(recipeLibraryFetch(userVersionAndType));
      dispatch(loginUserSuccess({ user, userVersionAndType }));
      NavigationService.navigate('Home');
    })
    .catch(error => dispatch(loginUserFail(error.message)));
};

Answer 1

你创造了一个manual mock for a user module。

激活特定测试文件的用户模块的手动模拟需要调用jest.mock。

对于这个特殊情况，将此行添加到__tests__/actions/AuthActions.test.js的顶部，mock将用于该测试文件中的所有测试：

jest.mock('../../app/utils/NavigationService');  // use the manual mock in this test file

---

请注意，必须通过调用fs为特定测试文件激活用户模块和节点核心模块（如path，util，jest.mock等）的手动模拟，并且此行为与Node模块的手动模拟不同它们会自动应用于所有测试。