27

我正在尝试使用 react、redux-mock-store 和 redux 编写一些测试，但我不断出错。也许是因为我Promise的还没有解决？

当fetchListing()我在开发和生产中尝试它时，动作创建器实际上可以工作，但是我在通过测试时遇到了问题。

错误信息

(node:19143) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 3): SyntaxError
(node:19143) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
 FAIL  src/actions/__tests__/action.test.js
  ● async actions › creates "FETCH_LISTINGS" when fetching listing has been done

    TypeError: Cannot read property 'then' of undefined

      at Object.<anonymous> (src/actions/__tests__/action.test.js:44:51)
          at Promise (<anonymous>)
      at Promise.resolve.then.el (node_modules/p-map/index.js:42:16)
          at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:169:7)

  async actions
    ✕ creates "FETCH_LISTINGS" when fetching listing has been done (10ms)

动作/index.js

// actions/index.js
import axios from 'axios';

import { FETCH_LISTINGS } from './types';

export function fetchListings() {

  const request = axios.get('/5/index.cfm?event=stream:listings');

  return (dispatch) => {
    request.then(( { data } ) => {
      dispatch({ type: FETCH_LISTINGS, payload: data });
    });
  }
};

action.test.js

// actions/__test__/action.test.js

import configureMockStore from 'redux-mock-store';
import thunk from 'redux-thunk';
import { applyMiddleware } from 'redux';
import nock from 'nock';
import expect from 'expect';

import * as actions from '../index';
import * as types from '../types';


const middlewares = [ thunk ];
const mockStore = configureMockStore(middlewares);

describe('async actions', () => {
  afterEach(() => {
    nock.cleanAll()
})


it('creates "FETCH_LISTINGS" when fetching listing has been done', () => {
  nock('http://example.com/')
    .get('/listings')
    .reply(200, { body: { listings: [{ 'corpo_id': 5629, id: 1382796, name: 'masm' }] } })

    const expectedActions = [
      { type: types.FETCH_LISTINGS }, { body: { listings: [{ 'corpo_id': 5629, id: 1382796, name: 'masm' }] }}
    ]

    const store = mockStore({ listings: [] })

    return store.dispatch(actions.fetchListings()).then((data) => {
      expect(store.getActions()).toEqual(expectedActions)
    })
  })
})
4

4 回答 4

17

store.dispatch(actions.fetchListings())返回undefined。你不能这么.then说。

请参阅redux-thunk 代码。它执行您返回的函数并将其返回。您返回的函数不fetchListings返回任何内容，即undefined.

尝试

return (dispatch) => {
    return request.then( (data) => {
      dispatch({ type: FETCH_LISTINGS, payload: data });
    });
  }

之后，您仍然会遇到另一个问题。你不会在你的内部返回任何东西then，你只会发送。这意味着下一个thengetundefined参数

于 2017-07-05T13:28:39.070 回答
9

我也知道这是一个旧线程，但您需要确保在 thunk 中返回异步操作。

在我的想法中，我需要：

return fetch()

异步操作并且有效

于 2017-12-24T03:53:18.443 回答
4

你的动作创建者应该返回一个承诺，如下所示：

// actions/index.js
import axios from 'axios';

import { FETCH_LISTINGS } from './types';

export function fetchListings() {
  return (dispatch) => {
    return axios.get('/5/index.cfm?event=stream:listings')
    .then(( { data } ) => {
      dispatch({ type: FETCH_LISTINGS, payload: data });
    });
  }
};

于 2019-06-09T15:03:44.887 回答
3

我知道这是一个旧线程。但我认为问题在于您的动作创建者不是异步的。

尝试：

export async function fetchListings() {
  const request = axios.get('/5/index.cfm?event=stream:listings');
  return (dispatch) => {
    request.then(( { data } ) => {
      dispatch({ type: FETCH_LISTINGS, payload: data });
    });
  }
}
于 2017-12-17T00:21:08.017 回答