模拟内部axios.create（）

Question

我正在使用jest并axios-mock-adapter测试异步操作创建者中的axiosAPI调用redux。

当我使用axios这样创建的实例时，我无法使其工作axios.create()：

import axios from 'axios';

const { REACT_APP_BASE_URL } = process.env;

export const ajax = axios.create({
  baseURL: REACT_APP_BASE_URL,
});

我会async action creator像这样消耗它：

import { ajax } from '../../api/Ajax'

export function reportGet(data) {
  return async (dispatch, getState) => {
    dispatch({ type: REQUEST_TRANSACTION_DATA })

    try {
      const result = await ajax.post(
         END_POINT_MERCHANT_TRANSACTIONS_GET,
         data,
      )
      dispatch({ type: RECEIVE_TRANSACTION_DATA, data: result.data })
      return result.data
    } catch (e) {
      throw new Error(e);
    }
  }
}

这是我的测试文件：

import {
  reportGet,
  REQUEST_TRANSACTION_DATA,
  RECEIVE_TRANSACTION_DATA,
} from '../redux/TransactionRedux'
import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'
import { END_POINT_MERCHANT_TRANSACTIONS_GET } from 'src/utils/apiHandler'
import axios from 'axios'
import MockAdapter from 'axios-mock-adapter'

const middlewares = [thunk]
const mockStore = configureMockStore(middlewares)
const store = mockStore({ transactions: {} })

test('get report data', async () => {
  let mock = new MockAdapter(axios)

  const mockData = {
    totalSalesAmount: 0
  }

  mock.onPost(END_POINT_MERCHANT_TRANSACTIONS_GET).reply(200, mockData)

  const expectedActions = [
    { type: REQUEST_TRANSACTION_DATA },
    { type: RECEIVE_TRANSACTION_DATA, data: mockData },
  ]

  await store.dispatch(reportGet())
  expect(store.getActions()).toEqual(expectedActions)
})

而且我只能执行一个操作，Received: [{"type": "REQUEST_TRANSACTION_DATA"}]因为ajax.post。

我尝试了多种方法来嘲笑该方法，axios.create但没有真正知道自己在做什么。

Answer 1

好，我知道了。这是我的解决方法！我最终 没有 做任何模拟库axios！

创建一个模拟axios在src/__mocks__：

// src/__mocks__/axios.ts

const mockAxios = jest.genMockFromModule('axios')

// this is the key to fix the axios.create() undefined error!
mockAxios.create = jest.fn(() => mockAxios)

export default mockAxios

然后在您的测试文件中，要旨将如下所示：

import mockAxios from 'axios'
import configureMockStore from 'redux-mock-store'
import thunk from 'redux-thunk'

// for some reason i need this to fix reducer keys undefined errors..
jest.mock('../../store/rootStore.ts')

// you need the 'async'!
test('Retrieve transaction data based on a date range', async () => {
  const middlewares = [thunk]
  const mockStore = configureMockStore(middlewares)
  const store = mockStore()

  const mockData = {
    'data': 123
  }

  /** 
   *  SETUP
   *  This is where you override the 'post' method of your mocked axios and return
   *  mocked data in an appropriate data structure-- {data: YOUR_DATA} -- which
   *  mirrors the actual API call, in this case, the 'reportGet'
   */
  mockAxios.post.mockImplementationOnce(() =>
    Promise.resolve({ data: mockData }),
  )

  const expectedActions = [
    { type: REQUEST_TRANSACTION_DATA },
    { type: RECEIVE_TRANSACTION_DATA, data: mockData },
  ]

  // work
  await store.dispatch(reportGet())

  // assertions / expects
  expect(store.getActions()).toEqual(expectedActions)
  expect(mockAxios.post).toHaveBeenCalledTimes(1)
})