I'm trying to write some test using react, redux-mock-store and redux, but I keep getting and error. Maybe because my Promise
has not yet been resolved?
The fetchListing()
action creator actually works when I try it on dev and production, but I'm having problems making the test pass.
error message
(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)
action/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)
})
})
})
store.dispatch(actions.fetchListings())
returns undefined
. You can't call .then
on that.
See redux-thunk code. It executes the function you return and returns that. The function you return in fetchListings
returns nothing, i.e. undefined
.
Try
return (dispatch) => {
return request.then( (data) => {
dispatch({ type: FETCH_LISTINGS, payload: data });
});
}
After that you will still have another problem. You don't return anything inside your then
, you only dispatch. That means the next then
gets undefined
argument
I also know this is an old thread but you need to make sure you return the async action inside of your thunk.
In my thunk I needed to:
return fetch()
the async action and it worked
I know this is an old thread. But I think the issue is that your action creator is not asynchronous.
Try:
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 });
});
}
}
Your action creator should return a promise as shown below:
// 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 });
});
}
};
来源:https://stackoverflow.com/questions/44927548/cannot-read-property-then-of-undefined-when-testing-async-action-creators-wit