vite+ts+vue3 知识点（定义全局函数和变量）

main.ts

import { createApp } from "vue";
import "./style.css";
import App from "./App.vue";
const app = createApp(App);

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

// 扩充声明文件
declare module "vue" {
  export interface ComponentCustomProperties {
    $filter: Filter;
    $env: string;
  }
}

// 全局变量
app.config.globalProperties.$env = "dev";

// 全局方法
app.config.globalProperties.$filter = {
  fix<T>(str: T) {
    return `梁延涛是${str}`;
  },
};

app.mount("#app");

组件中使用

<template>
  <div>
    <Son a="123" b="456"></Son>
    <!-- 变量可以直接放在插值运算符中使用 -->
    <div>{{ $filter.fix('???') }}---{{ $env }}</div>
  </div>
</template>

<script setup lang="ts">
import Son from './components/Son1.vue'
// 获取实例
import { getCurrentInstance } from 'vue'
const app = getCurrentInstance()

console.log(app?.proxy?.$filter.fix('!!!'));

</script>

<style scoped lang="less">

</style>