vue引入ts main.ts报错

vue引入ts main.ts报错：
unused expression, expected an assignment or function call

import Vue from 'vue'
import App from '@/App.vue'
import router from '@/router/index.ts'

new Vue({
  el: '#app',
  router,
  components: { App },
  template: '<App/>'
})

npm run dev 运行后

 WARNING  Compiled with 1 warnings                                                                                                                                                                     11:16:22 AM

 warning  in ./src/main.ts

[8, 1]: unused expression, expected an assignment or function call

解决了吗兄弟