Wie ein Import mit Scherz

Question

Ich habe eine kleine redux Middleware wie so

import { hashHistory } from 'react-router' 
import { REDIRECT_TO_LOGIN_REDIRECT_URL } from '../actions/login-redirect'; 

export default store => next => action => { 

    if (action.type === REDIRECT_TO_LOGIN_REDIRECT_URL) { 
     hashHistory.push(store.getState().loginRedirectUrl); 
    } 

    return next(action) 
} 

verspotten, die ich jetzt testen möchten. Wie Sie in Zeile 1 sehen können, importiere ich hashHistory und benutze es später. Dies möchte ich testen (der Anruf an hashHistory). Um das zu tun, müsste ich hashHistory vortäuschen, aber ich weiß nicht wie. Ich verwende jest:

import { REDIRECT_TO_LOGIN_REDIRECT_URL } from '../actions/login-redirect'; 
import redirectMiddleware from './redirect-after-login'; 

describe('redirect after login middleware',() => { 

    function setup() { 
     const store = { 
      subscribe:() => {}, 
      dispatch:() => {}, 
      getState:() => ({}) 
     }; 
     const next = jest.fn(); 
     const action = { type: REDIRECT_TO_LOGIN_REDIRECT_URL }; 
     return { store, next, action }; 
    } 

    it('should push the redirect URL to the hashHistory',() => { 
     // How to test it? 
    }) 

}); 

Answer 1

Sie können die react-router Modul wie diese verspotten:

import { hashHistory } from 'react-router' 
import { REDIRECT_TO_LOGIN_REDIRECT_URL } from '../actions/login-redirect'; 
import redirectMiddleware from './redirect-after-login'; 

jest.mock('react-router',() => ({hashHistory: { push: jest.fn()})) 

describe('redirect after login middleware',() => { 

    function setup() { 
     const store = { 
      subscribe:() => {}, 
      dispatch:() => {}, 
      getState:() => ({loginRedirectUrl: 'someLoginRedirectUrl'}) 
     }; 
     const next = jest.fn(); 
     const action = { type: REDIRECT_TO_LOGIN_REDIRECT_URL }; 
     return { store, next, action }; 
    } 

    it('should push the redirect URL to the hashHistory',() => { 
     const { store, next, action } = setup() 
     redirectMiddleware(store)(next)(action) 
     expect(hashHistory.push).toHaveBeenCalledWith('someLoginRedirectUrl') 
    }) 

});