使用 fetch-mock 测试 React Redux 异步操作 - "Cannot read property 'then' of undefined"

Question

我在测试 react redux 异步操作时遇到了一些问题，由于某些原因 store.dispatch returns 未定义并且 .then 方法不起作用。

当我 console.log store.dispatch(actions.requestChartData()) 它给我以下错误：

fetch-mock: No fallback response defined for GET to https://swapi.co/api/people

表示没有模拟响应并且未定义。

我不知道我的错误在哪里，在 url 或者我遗漏了什么。任何帮助将不胜感激

这是我的 action.js 代码：

import {
    ROOT_URL,
    API_KEY,
    FETCH_POSTS,
    CREATE_POST,
    REQUEST_CHART_DATA_PENDING,
    REQUEST_CHART_DATA_SUCCESS,
    REQUEST_CHART_DATA_FAILED
} from '../constants/constants'

export const requestChartData = () => (dispatch) => {
    dispatch({type: REQUEST_CHART_DATA_PENDING})

    fetch('https://swapi.co/api/people')
        .then(response => response.json())
        .then(data => dispatch({type: REQUEST_CHART_DATA_SUCCESS, 
                labels: data.results.map(label => label.name),
                chartData: data.results.map(chartData => chartData.height )}))

        .catch(error => dispatch({type: REQUEST_CHART_DATA_FAILED, payload: error}))        
}

还有我的 action.test.js 文件：

import * as actions from '../../actions/index'
import fetchMock from 'fetch-mock'
import {
    ROOT_URL,
    API_KEY,
    FETCH_POSTS,
    CREATE_POST,
    REQUEST_CHART_DATA_PENDING,
    REQUEST_CHART_DATA_SUCCESS,
    REQUEST_CHART_DATA_FAILED
} from '../../constants/constants'

import thunkMiddleware from 'redux-thunk'
import configureMockStore from 'redux-mock-store'

const mockStore = configureMockStore([thunkMiddleware])

describe('fetching api url', () => {
 afterEach(() => {
   fetchMock.restore()
 })

 it('creates REQUEST_CHART_DATA_SUCCESS when fetching has been done', () => {
   fetchMock.getOnce('https://swapi.co/api/people', {
  body: { todos: ['do something'] },
  headers: { 'content-type': 'application/json' }
   })
  
   const expectedActions = 
  { type: REQUEST_CHART_DATA_SUCCESS, body: { todos: ['do something'] } }
 
   const store = mockStore({ todos: [] })
  
   return store.dispatch(actions.requestChartData()).then(() => {
  
  expect(store.getActions()).toEqual(expectedActions)
   })
  })
  })

Answer 1

在您的 requestChartData 操作创建器中，return fetch 而不是仅仅调用它。 return fetch('/你的-api-路径')

使用 fetch-mock 测试 React Redux 异步操作 - "Cannot read property 'then' of undefined"

Testing React Redux Async Actions with fetch-mock - "Cannot read property 'then' of undefined"

javascript

testing

reactjs

react-redux

fetch-mock