编写postcss插件，全局css文件px转vw

跟目录下创建plugins文件夹，创建postcss-px-to-viewport.ts文件

 文件内代码：

// postcss 的插件 vite内置了postCss插件 无需安装
import { Plugin } from 'postcss';
 
interface Options {
    viewportWidth: number
}
 
const Options = {
    viewportWidth: 375, // UI设计稿给多少写多少，默认375
}
export const PostCsspxToViewport = (options:Options):Plugin => {
    const opt = Object.assign({}, Options, options)
    return {
        postcssPlugin: 'postcss-px-to-viewport',
        // 钩子函数
        Declaration(node) {
            if (node.value.includes('px')) {
                const num = parseFloat(node.value);
                node.value = `${((num / opt.viewportWidth) * 100).toFixed(2)}vw`
            }
        }
    }
}
 

tsconfig.node.json文件增加plugins引入

{
  "compilerOptions": {
    "composite": true,
    "skipLibCheck": true,
    "module": "es2022",
    "moduleResolution": "bundler",
    "allowSyntheticDefaultImports": true,
    "noImplicitAny": false// 允许隐式的any
  },
  "include": [
    "vite.config.ts",
    "plugins/**/*.ts",
    "src/**/*.ts",
  ]
}

vite. config.ts文件中引入PostCsspxToViewport方法