feat(runtime-core): add ComponentCustomProperties interface

[posva]

Export an interface to allow typing for TS and JS users (free autocompletion) to custom added properties.

Here is an example of adding a property $router to every component instance:

import { createApp } from 'vue'
import { Router, createRouter } from 'vue-router'

declare module '@vue/runtime-core' {
  interface ComponentCustomProperties {
    $router: Router
  }
}

// effectively adding the router to every component instance
const app = createApp({})
const router = createRouter()
app.config.globalProperties.$router = router

const vm = app.mount('#app')
// we can access the router from the instance
vm.$router.push('/')

[posva]

There seems to be an unrelated test failing (I only changed typings)

[yyx990803]

Ugh, why does GitHub forget the preference and reverted back to normal merge? This has happened a few times lately.

[yyx990803]

I manually squashed and force pushed ¯_(ツ)_/¯

[bhabgs]

Why not on the d.ts use it ?

(为什么不能在d.ts 中设置这个？)

declare module '@vue/runtime-core' {
  interface ComponentCustomProperties {
    $router: Router
  }
}

[tcstory]

Why not on the d.ts use it ?

(为什么不能在d.ts 中设置这个？)

declare module '@vue/runtime-core' {
  interface ComponentCustomProperties {
    $router: Router
  }
}

I also want to known why I can not place the code in the shims-vue.d.ts. I had tried to place the code in shims-vue.d.ts, and i got another errors.

[Zenthae]

Why not on the d.ts use it ?
(为什么不能在d.ts 中设置这个？)

declare module '@vue/runtime-core' {
  interface ComponentCustomProperties {
    $router: Router
  }
}

I also want to known why I can not place the code in the shims-vue.d.ts. I had tried to place the code in shims-vue.d.ts, and i got another errors.

you have to put the new declaration in the main.ts file