error in unit test vue.js karma : undefined is not a constructor ()

问题:

This is my first unit test and I'm getting an error message that couldn't find why I get it in the forums so far.

This is my unit test:

import LoginPage from 'src/pages/Login'  describe('Login.vue', () => { it('mounted is a fuction', () => {     expect(typeof LoginPage.mounted).toBe('function') }) }) 

And this is the login page:

<template> <div class="">     <p v-if="$route.query.redirect">        You need to login first.     </p>     <form class="column is-one-third is-offset-one-third" @submit.prevent="login">     <div class="control">         <input type="email" placeholder="email" v-model="email" class="input">     </div>     <div class="control">         <input type="password" autocomplete="off" placeholder="password" v-model="pass" class="input">     </div>     <div class="control">         <button class="button is-primary" type="submit">Login</button>         <a class="button" href="/signup">Sign up</button>     </div>     <p v-if="error" class="help is-danger">{{ error }}</p> </form> </div> </template> <script> export default { props: ['state'], data () { return {     email: '',     pass: '',     error: ''   } }, mounted () { if (this.state.auth.currentUser) {     this.$router.replace(this.$route.query.redirect || '/') } }, methods:  { ....// } } 

and this is the error message that I get :

mounted is a fuction Login.vue undefined is not a constructor (evaluating 'expect((0, _typeof3.default)(_Login2.default.mounted)).toBe('function')') webpack:///test/unit/specs/Component.spec.js:5:42 <- index.js:161:65 

Thanks for your help

回答1:

There are two points you are missing here.

Firstly, you won't get methods on a vue component just like that, vue internally proxies the methods, data etc such that they can be referenced via this maybe this led to your confusion.

Solution: componentName.methods.methodName in your case LoginPage.methods.mounted

that changes your code to:

import LoginPage from 'src/pages/Login'  describe('Login.vue', () => {   it('mounted is a fuction', () => {     expect(typeof LoginPage.methods.mounted).toBe('function')   }) }) 

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