Javascript 使用Jest对redux异步函数进行单元测试

我对单元测试还很陌生，所以请原谅我的任何不妥之处

我有一个文件

api.js

，其中包含应用程序的所有api调用函数。每个函数都返回其承诺。下面是它的外观：

api.js

现在来看我要测试的redux异步操作。它看起来像这样：

getDataAction.js

现在，在我的测试文件中，我尝试了以下方法：

getDataAction.test.js

这给我带来了一个错误：

TypeError: Cannot read property 'end' of undefined

---

我做错了什么？现在我可以用Jest的默认自动模拟程序模拟api.js，但是如何处理使用

end

运行回调函数的情况呢？非常感谢你的帮助

模拟的

api

需要返回一个函数，该函数返回具有

end

函数的对象：

import api from 'api' //to set the implantation of getData we need to import the api into the test

// this will turn your api into an object with the getData function
// initial this is just a dumb spy but you can overwrite its behaviour in the test later on 
jest.mock('api.js', ()=> ({getData: jest.fn()}));

describe('getData Action', () => {
  it('gets the data', () => {
    const result = {test: 1234}
    // for the success case you mock getData so that it returns the end function that calls the callback without an error and some data
    api.getData.mockImplementation(() => ({end: cb => cb(null, result)}))
    expect(store.dispatch(getData())).toEqual(expectedAction);
  });

 it('it thows on error', () => {

    // for the error case you mock getData so that it returns the end function that calls the callback with an error and no data
    api.getData.mockImplementation(() => ({end: cb => cb({status: 'someError'}, null)}))
    expect(store.dispatch(getData())).toThrow();
  });
});

jest.mock('api.js');
describe('getData Action', () => {
  it('gets the data', () => {
    expect(store.dispatch(getData())).toEqual(expectedAction);
  });
});

TypeError: Cannot read property 'end' of undefined

import api from 'api' //to set the implantation of getData we need to import the api into the test

// this will turn your api into an object with the getData function
// initial this is just a dumb spy but you can overwrite its behaviour in the test later on 
jest.mock('api.js', ()=> ({getData: jest.fn()}));

describe('getData Action', () => {
  it('gets the data', () => {
    const result = {test: 1234}
    // for the success case you mock getData so that it returns the end function that calls the callback without an error and some data
    api.getData.mockImplementation(() => ({end: cb => cb(null, result)}))
    expect(store.dispatch(getData())).toEqual(expectedAction);
  });

 it('it thows on error', () => {

    // for the error case you mock getData so that it returns the end function that calls the callback with an error and no data
    api.getData.mockImplementation(() => ({end: cb => cb({status: 'someError'}, null)}))
    expect(store.dispatch(getData())).toThrow();
  });
});