// 之前 (Vue 2.x)
Vue.prototype.$http = () => {}

// 之后 (Vue 3.x)
const app = createApp({})
app.config.globalProperties.$http = () => {}

app.config.globalProperties.$filters = {
  format<T extends any>(str: T): string {
    return `$${str}`
  }
}

type Filter = {
    format<T>(str: T): string
}

// 声明要扩充@vue/runtime-core包的声明.
// 这里扩充"ComponentCustomProperties"接口, 因为他是vue3中实例的属性的类型.
declare module 'vue' {
    export interface ComponentCustomProperties {
        $filters: Filter
    }
}

import { getCurrentInstance, ComponentInternalInstance } from 'vue';

const { appContext } = <ComponentInternalInstance>getCurrentInstance()

console.log(appContext.config.globalProperties.$env);

推荐第二种方式

import {ref,reactive,getCurrentInstance} from 'vue'
const app = getCurrentInstance()
console.log(app?.proxy?.$filters.format('js'))