vue-learn/src/router/index.js

import Vue from 'vue'
import VueRouter from 'vue-router'
import Login from '../components/Login'
import Home from '../components/Home'

Vue.use(VueRouter)

const routes = [
  {
    path: '/', redirect: '/login'
  },
  {
    path: '/login',
    component: Login
  },
  {
    path: '/home',
    component: Home
  }
]

const router = new VueRouter({
  routes
})
router.beforeEach((to, from, next) => {
  if (to.path === '/login') {
    return next()
  }
  const token = sessionStorage.getItem('token')
  if (!token) {
    return next('/login')
  }
  next()
})
export default router