Vue异步加载about组件

Vue.component('about', {template: '<div>ABOUT PAGE</div>'}); 

<div id="app">
 <router-link to="/home">/home</router-link>
 <router-link to="/about">/about</router-link>
 <router-view></router-view>
 </div>
 <script src="static/js/vue.min.js"></script>
 <script src="static/js/vue-router.js"></script>
 <script>
 function load (componentName, path) {
 return new Promise(function (resolve, reject){
 var script = document.createElement('script');
 script.src = path;
 script.async = true;
 script.onload = function () {
 var component = Vue.component(componentName);
 if (component) {
 resolve(component);
 } else {
 reject();
 }
 }
 document.body.appendChild(script);
 });
 }
 var router = new VueRouter({
 routes: [{
 path: '/',
 redirect: '/home'
 }, {
 path: '/home',
 component: {
 template: '<div>HOME PAGE</div>'
 }
 },{
 path: '/about',
 component: function (resolve, reject) {
 load('about', 'static/js/business/about.js').then(resolve, reject);
 }
 }]
 });
 var app = new Vue({
 el: '#app',
 router: router
 });
 </script>