开玩笑 - 测试给出错误 TypeError: Cannot read property 'then' of undefined

Posted 2023-03-28

【中文标题】开玩笑 - 测试给出错误 TypeError: Cannot read property \'then\' of undefined

【英文标题】：Jest - Test gives an error TypeError: Cannot read property 'then' of undefined开玩笑 - 测试给出错误 TypeError: Cannot read property 'then' of undefined

【发布时间】：2018-11-01 05:30:13

【问题描述】：

当我运行测试时，它给了我一个错误 TypeError: Cannot read property 'then' of undefined，我试图在 Docs 上寻找一些修复，但我没有找到解决这个问题的方法，任何想法非常感谢如何解决此问题。

contact-actions.js

 export function getContacts() 
      return function(dispatch) 
        dispatch(type: 'GET_CONTACTS_PENDING')
        axios.get('http://127.0.0.1:8000/api/contacts',  
        )
          .then((response) => 
            dispatch(type: 'GET_CONTACTS', payload: response.data)
            dispatch(hideLoading())
          )
          .catch((error) => 
            dispatch(type:  'CONTACT_ERROR', payload: error)
        )
      
    


    app.spec.js

    import React from 'react';
    import  shallow, mount  from 'enzyme';
    import renderer from 'react-test-renderer';
    import MockAdapter from 'axios-mock-adapter';
    import configureMockStore from 'redux-mock-store';
    import nock from 'nock';
    import axios from 'axios';
    import moxios from 'moxios';
    import expect from 'expect';
    import thunk from 'redux-thunk';
    import  Provider  from 'react-redux';
    import * as actions from '../src/actions/contact-actions';
    import * as types from '../src/constants/action-types';

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

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

      it('creates GET_CONTACTS when fetching contacts has been done', () => 
        const store = mockStore();

        const contacts = ;

        nock('http://127.0.0.1:8000')
          .get('/api/contacts')
          .reply(200,  body:   contacts: [ first_name: 'shadow', last_name: 'madow', phone: 5566, email: '[e-mail]' ]  );

        const expectedActions = [
           type: types.GET_CONTACTS, body:   contacts: [ first_name: 'shadow', last_name: 'madow', phone: 5566, email: '[e-mail]' ] 
        ];

        return store.dispatch(actions.getContacts()).then(() => 
          // return of async actions
          expect(store.getActions()).toEqual(expectedActions);
        );
      );
    );

【参考方案1】：

确保从 getContacts() 中的匿名函数返回承诺：

export function getContacts() 
  return function(dispatch) 
    dispatch(type: 'GET_CONTACTS_PENDING')
    axios.get('http://127.0.0.1:8000/api/contacts',  // THIS LINE
    )
    ...

改变这个：

axios.get('http://127.0.0.1:8000/api/contacts', 

到这里：

return axios.get('http://127.0.0.1:8000/api/contacts', 

现在它缺少 return 语句，因此返回 undefined。

【讨论】：

给我错误异步操作 › 在获取联系人完成后创建 GET_CONTACTS expect(received).toEqual(expected) 预期值等于：["body": “联系人”：[“电子邮件”：“[e-mail]”，“名字”：“影子”，“姓氏”：“madow”，“电话”：5566]，“类型”：“GET_CONTACTS” ] 收到：["payload": [Error: Network Error], "type": "CONTACT_ERROR"]

好吧，这就是进步！ ;) 你原来的问题已经解决了。对于下一个问题，我将尝试在您的 .then((response) => 函数体中进行一些调试，以查看它是否在错误之前被命中。也可以尝试仔细检查真正的端点没有被击中。