单元测试Redux异步操作

Question

这是我的异步操作，涉及api调用和操作创建者

export const getPosts = () => (dispatch) => {
dispatch({ type: LOADING_DATA });
axios
.get(`/posts`)
.then(res => {
dispatch({
type: SET_POSTS,
payload: res.data
});
})
.catch(err => {
dispatch({
type: SET_POSTS,
payload: []
});
});
};

我正在测试当调用getPosts时，它将调度LOADING_DATA，然后是SET_POSTS。

import axios from 'axios';
import moxios from 'moxios';
import expect from 'expect';
import thunk from 'redux-thunk';
import configureMockStore from 'redux-mock-store';
import { getPosts } from '../actions/dataActions';
import { LOADING_DATA, SET_POSTS } from '../actions/actionTypes';
describe('dataActions', () => {
const middlewares = [thunk];
const mockStore = configureMockStore(middlewares);
beforeEach(() => {
moxios.install();
});
// getPosts - when calling LOADING_DATA, we dispatch SET_POSTS with expected payload
it('should dispatch an action to get posts', () => {
moxios.wait(() => {
const request = moxios.requests.mostRecent();
request.respondWith({
status: 200
});
});
const expectedActions = [
{ type: LOADING_DATA},
{ type: SET_POSTS}
]
const store = mockStore({ posts: [] })
return store.dispatch(getPosts()).then(() => {
expect(store.getActions()).toEqual(expectedActions);
});
})
afterEach(() => {
moxios.uninstall();
});
})

但是，我收到的是TypeError: Cannot read property 'then' of undefined。我感谢你的帮助。

Answer 1

您的操作不会返回任何promise，以便您可以使用then在测试用例中处理它
您需要在调用axios之前将return语句添加到操作中。

export const getPosts = () => (dispatch) => {
dispatch({ type: LOADING_DATA });
//Just add return statement
return axios
.get(`/posts`)
.then(res => {
dispatch({
type: SET_POSTS,
payload: res.data
});
})
.catch(err => {
dispatch({
type: SET_POSTS,
payload: []
});
});
};

我也面临着同样的问题，我就这样解决了！