Observable epics not running service call - rxjs

Question

I try to follow the example in the documentation to test epic:
Epic
import { ofType } from 'redux-observable';
import { combineEpics } from 'redux-observable';
import 'rxjs/add/operator/takeUntil';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';
import { switchMap } from 'rxjs/add/operator/switchMap';
import { from } from 'rxjs/observable/from';
import { of } from 'rxjs/observable/of';
import { fromPromise } from 'rxjs/observable/fromPromise';
import {
getTopStories
} from '../../../utils/service-helper';
import { type, actions } from './action';
export const getHackernewsStoryEpic = (action$, store) =>
action$.ofType(type.GET_HACKERNEWS_STORIES_REQUEST)
.switchMap(
action => {
return from(getTopStories())
.takeUntil(action$.ofType(type.GET_HACKERNEWS_STORIES_REQUEST_CANCEL))
.map(result => actions.getHackernewsStoriesRequestSuccess(result))
.catch((error) => actions.getHackernewsStoriesRequestFailure(error))
}
);
export default combineEpics(
getHackernewsStoryEpic
);
Get getTopStories is service call which talks to hackernews API:
export const getTopStories = async () => await getRequest('/topstories.json');
My test looks like this:
describe('Hackernews stories epic', () => {
describe('getHackernewsStoryEpic', () => {
let store;
beforeEach(() => {
store = mockStore();
});
afterEach(() => {
nock.cleanAll();
epicMiddleware.replaceEpic(storiesEpic);
});
it('should return success on request success', async () => {
store.dispatch({ type: type.GET_HACKERNEWS_STORIES_REQUEST });
expect(store.getActions()).toEqual([
{ type: type.GET_HACKERNEWS_STORIES_REQUEST },
{ type: type.GET_HACKERNEWS_STORIES_SUCCESS }
]);
});
});
});
Looking at the test it fails as one action is trigger and getTopStories() is never trigger (nock is not complaining that there is no mock) and not getting next action. I think I missing something as from should run async call?

Answer 1

it('should return success on request success', async () => {
const mock = require('../../../../data/hackernews/topstories.json');
nock(__ROOT_API__)
.defaultReplyHeaders({ 'access-control-allow-origin': '*' })
.get('/topstories.json')
.reply(200, mock);
const action$ = ActionsObservable.of(
{type: type.GET_HACKERNEWS_STORIES_REQUEST}
);
const expectedAction = [actions.getHackernewsStoriesRequestSuccess(mock)]
await getHackernewsStoryEpic(action$)
.toArray()
.toPromise()
.then(actualOutputActions => {
expect(actualOutputActions).toEqual(expectedAction)
});
});