vue-router: Loading asynchronously a non .vue component fails

Version

2.5.2

Reproduction link

https://github.com/fpoliquin/vue-bug-async.git

Steps to reproduce

Create a simple JavaScript or TypeScript component:

Async.ts

import Vue from 'vue'
import Component from 'vue-class-component'

@Component({
    template: '<p>Hello {{msg}}</p>'
})
export default class Async extends Vue {
    msg: 'world'
}

Try to load async:

Router.ts

const Async = resolve => require(['Async'], resolve)

export default new Router({
    mode: 'history',
    routes: [
        {
            path: '/async',
            component: Async
        }
    ...

What is expected?

The component should be mounted and operational after loading the webpack chunk

What is actually happening?

The console shows this error:

Failed to mount component: template or render function not defined.

---

I found a workaround by replacing a little piece of code : From src/history/base.js line 341

          // save resolved on async factory in case it's used elsewhere
          def.resolved = typeof resolvedDef === 'function'
            ? resolvedDef
            : _Vue.extend(resolvedDef)
          match.components[key] = resolvedDef

To

          if (resolvedDef.default) {
            def.resolved = resolvedDef.default;
            match.components[key] = resolvedDef.default;
          } else {
            // save resolved on async factory in case it's used elsewhere
            def.resolved = typeof resolvedDef === 'function'
              ? resolvedDef
              : _Vue.extend(resolvedDef);
            match.components[key] = resolvedDef;
          }

This works for me but I am not sure if it is a good fix for everyone else…