开玩笑，如何在对象解构中模拟导入的回调？

Question

我按以下方式进行了测试，但它困扰着我如何需要导入具有函数的对象，而不仅仅是导入函数。

这行得通

//service.test.js
const get = require('../../modules/bankUser/model/getRegisteredUser');

    get.getRegisteredUser = jest.fn()
      .mockImplementationOnce(async () => mock)
      .mockImplementationOnce(async () => mockUpdated);

//service.js
const get = require('../model/getRegisteredUser');

const testedFunction () => {
  const depositReciver = await get.getRegisteredUser(depositName, depositCpf);
}

这个剂量

//service.test.js
const get = require('../../modules/bankUser/model/getRegisteredUser');

    get.getRegisteredUser = jest.fn()
      .mockImplementationOnce(async () => mock)
      .mockImplementationOnce(async () => mockUpdated);

//service.js
const { getRegisteredUser } = require('../model/getRegisteredUser');

const testedFunction () => {
  const depositReciver = await getRegisteredUser(depositName, depositCpf);
}

我正在尝试这个 (way)：

//service.test.js
const get = require('../../modules/bankUser/model/getRegisteredUser');

    jest.mock('../../modules/bankUser/model/getRegisteredUser');
    get.mockImplementationOnce(() => ({ getRegisteredUser: () => mockObject }));

jest 返回这个：

TypeError: get.mockImplementationOnce is not a function

我也试过这样导入

//service.test.js
const { getRegisteredUser } = require('../../modules/bankUser/model/getRegisteredUser');

    jest.mock('../../modules/bankUser/model/getRegisteredUser');
    getRegisteredUser.mockImplementationOnce(() => ({ getRegisteredUser: () => mockObject }));

编辑

//getRegisteredUser.js
const { getConnection } = require('../../../global/connection');

const getRegisteredUser = async (userName, cpf) => {
  const db = await getConnection('Data-Base');
  const res = await db.collection('Collection')
    .findOne({ userName, cpf });
  return res;
};

module.exports = { getRegisteredUser };

Answer 1

您指向的示例 [https://jestjs.io/docs/es6-class-mocks#replacing-the-mock-using-mockimplementation-or-mockimplementationonce][1] 与默认导出有关，但我认为您在代码中使用了命名导出。

有多种方法可以做到这一点

一种方式

const get = require('../../modules/bankUser/model/getRegisteredUser');

jest.mock('../../modules/bankUser/model/getRegisteredUser');
get.getRegisteredUser.mockImplementationOnce(() => mockObject);

第二种方式

jest.mock('../../modules/bankUser/model/getRegisteredUser', () => ({
  ...jest.requireActual('../../modules/bankUser/model/getRegisteredUser'),
  getRegisteredUser: jest.fn().mockImplementation(() => mockObject),
}))

另一种方式

We can also mock a module using the __mocks__ directory which is inbuilt feature of jest

最后永远不要忘记在每次测试后调用 clearAllMocks() 否则它可能会影响其他测试的输出。

afterEach(() => {
  jest.clearAllMocks();
});