fix(generator): Template files for main.js and router when not using a compiler (#2828)

* fix(cli-service): ES5 compatibility -

Don't use arrow function in main.js when not using babel nor typescript.

* fix(router): es5 compatibility

use normal function instead of arrow function
in router.js when neither babel nor typescript are used.

Author: LinusBorg

packages/@vue/cli-service/generator/index.js

@@ -1,5 +1,7 @@
 module.exports = (api, options) => {
-  api.render('./template')
+  api.render('./template', {
+    doesCompile: api.hasPlugin('babel') || api.hasPlugin('typescript')
+  })
 
   api.extendPackage({
     scripts: {

packages/@vue/cli-service/generator/router/index.js

@@ -7,7 +7,8 @@ module.exports = (api, options = {}) => {
     }
   })
   api.render('./template', {
-    historyMode: options.routerHistoryMode
+    historyMode: options.routerHistoryMode,
+    doesCompile: api.hasPlugin('babel') || api.hasPlugin('typescript')
   })
 
   if (api.invoking) {

packages/@vue/cli-service/generator/router/template/src/router.js

@@ -21,7 +21,13 @@ export default new Router({
       // route level code-splitting
       // this generates a separate chunk (about.[hash].js) for this route
       // which is lazy-loaded when the route is visited.
+      <%_ if (doesCompile) { _%>
       component: () => import(/* webpackChunkName: "about" */ './views/About.vue')
+      <%_ } else { _%>
+      component: function () { 
+        return import(/* webpackChunkName: "about" */ './views/About.vue')
+      }
+      <%_ } _%>
     }
   ]
 })

packages/@vue/cli-service/generator/template/src/main.js

@@ -4,5 +4,9 @@ import App from './App.vue'
 Vue.config.productionTip = false
 
 new Vue({
-  render: h => h(App)
+  <%_ if (doesCompile) { _%>
+  render: h => h(App),
+  <%_ } else { _%>
+  render: function (h) { return h(App) },
+  <%_ } _%>
 }).$mount('#app')