How to mock store to test actions in a redux app

mockStore.js

// Our action to fetch all places in actions/index.js
export function fetchPlaces() {
  return dispatch => {
    return axios.get('/api/places/fetchAll')
      .then(resp => {
        dispatch(updatePlaces(resp.data));
      })
      .catch(err => {
        console.log('Couldn\'t fetch places: ', err);
        dispatch(authError(err));
      });
  }
}

// In actions/actions.spec.js
import configureStore from 'redux-mock-store';
import promiseMiddleware from 'redux-thunk';

import expect, { createSpy } from 'expect';
import * as actions from './index';
import * as types from './types';

// Create our mock store with our promise middelware
const mockStore = configureStore([promiseMiddleware]);

describe('Async actions: ', () => {
  it('Fetches places', () => {
    const store = mockStore({}); // Ceate a mocked-store instance with an initial empty state
    return store.dispatch(actions.fetchPlaces())
      .then(() => {
        expect(store.getActions().length).toBe(1); // getActions() returns an array of the dispatched actions
        expect(store.getActions()[0].payload.data).toEqual(expectedPlaces);
        expect(store.getActions()[0].type).toBe(types.UPDATE_PLACES);
      });
  });
});