Creat file main.ts
and copy this code
import { createApp } from 'vue'
import App from './app.vue'
import './style.scss'
createApp(App).mount('#app')
create file app.vue
and import in main.ts
and then you do anything in app component. And then yarn dev
or npm run dev
// for run R&D
yarn dev
// or
npm run dev
// for run unit test
yarn test
// or
npm run test
// for run storybook
yarn storybook
// or
npm run storybook
// console.log(button.classes()) for see properti class