反应笑话单元测试用例TypeError：无法读取未定义的属性'then'

Posted 2023-02-22

【中文标题】反应笑话单元测试用例TypeError：无法读取未定义的属性\'then\'

【英文标题】：react jest unit test case TypeError: Cannot read property 'then' of undefined反应笑话单元测试用例TypeError：无法读取未定义的属性'then'

【发布时间】：2019-07-05 07:18:29

【问题描述】：

我已经使用 react、redux-mock-store 和 redux 编写了测试用例，但我不断出错。我在 *** 上检查了同样的错误，但我无法理解。

Cannot read property '.then' of undefined when testing async action creators with redux and react

这是我的 index.js 文件：

import  post  from '../../../service/index';
import  CREATE_JD_SUCCESS, CREATE_JD_FAILED, CREATE_JD_URL, REQUEST_INITIATED, REQUEST_SUCCESSED  from '../../../constants/AppConstants'

export function createJob(jd) 
  return (dispatch) => 
    dispatch(
      type: REQUEST_INITIATED
    );
    post(CREATE_JD_URL, jd)
      .then((response) => 
        if (response.status === 200) 
          dispatch(
            type: REQUEST_SUCCESSED,
          );
          dispatch(
            type: CREATE_JD_SUCCESS,
            data: response.payload,
          )
        
        else 
          dispatch(
            type: REQUEST_SUCCESSED
          );
          dispatch(
            type: CREATE_JD_FAILED,
            data: response.status,
          );
        
      )
  

这是我的 index.test.js 文件

import * as actions from '../index';
import configureMockStore from 'redux-mock-store';
import moxios from 'moxios';
import thunk from 'redux-thunk';
import apiGatewayEndpoint from '../../../../config/index';
import  CREATE_JD_SUCCESS, CREATE_JD_URL  from '../../../../constants/AppConstants';

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

const newJd = 
  "companyId": "12345",
  "jobDescription": 'Hello there'
;

const responseData = "job created!";

describe('actions for creating new job', () => 

  beforeEach(function () 
    moxios.install();
  );

  afterEach(function () 
    moxios.uninstall();
  );

  it('action for create job', async (done) => 
    let url = CREATE_JD_URL;
    moxios.stubRequest(apiGatewayEndpoint.apiGatewayEndpoint + url, 
      status: 200,
      response: responseData
    );
    const expectedActions = [ "type": "REQUEST_INITIATED" ,  "type": "REQUEST_SUCCESSED" ,  data: responseData, type: "CREATE_JD_SUCCESS" ];
    const store = mockStore();
    await store.dispatch(actions.createJob(newJd))
      .then(() => 
        expect(store.getActions()).toEqual(expectedActions);
      );
    done();
  );
);

在回答的上述链接上，他说错误即将到来是因为 store.dispatch() 方法返回 undefined.bt 在我的情况下，我的其他操作测试用例运行良好，这与我上面写的相同不知道为什么收到此错误。

运行 npm test 时出现控制台错误：

● actions for creating new jd › action for create jd

    TypeError: Cannot read property 'then' of undefined

      38 |     const expectedActions = [ "type": "REQUEST_INITIATED" ,  "type": "REQUEST_SUCCESSED" ,  data: responseData, type: "CREATE_JD_SUCCESS" ];
      39 |     const store = mockStore();
    > 40 |     await store.dispatch(actions.createJob(newJd))
         |           ^
      41 |       .then(() => 
      42 |         expect(store.getActions()).toEqual(expectedActions);
      43 |       );

如果有人知道，请指导我在这里做错了什么。任何帮助将不胜感激

【参考方案1】：

只需在 index.js 文件中的 post 调用之前写入 return。 例如：

return post(CREATE_JD_URL, jd)
      .then((response) => 
   ...

这对我有用。