How to use nodejs to separate js and css in html files (code example)

// extract-js-css
// import fs from 'fs'
var fs = require('fs')
// import csscomb from 'csscomb'
// var csscomb = require('csscomb')
// var comb = new csscomb('zen');
// console.log(comb)

// 删除文件
const deleteFile = (path)=>{
    return new Promise(resolve => {
        fs.unlink(path, (err) => {
            if (err) {
                console.log(err)
                return
            };
            console.log(`已成功删除 ${path}文件`);
            resolve()
        });
    })
}

// 删除文件夹
const deleteDir = async (path)=>{
    let  _files =  await new Promise (resolve => {
        fs.readdir(path, (err,files) => {
            if (err) {
                console.log(err)
            };
            console.log(`已成功读取 ${path} 文件夹`);
            resolve(files)
        })
    })

    if(_files && _files.length) {
        for(let i =0;i<_files.length> {
        fs.rmdir(path, (err) => {
            if (err) {
                console.log(err)
            };
            console.log(`已成功删除空 ${path}文件夹`);
            resolve()
        })
    });
}
const emptyDir = (path) => {
    return new Promise(resolve => {
        fs.rmdir(path, (err) => {
            if (err) {
                console.log(err)
            };
            console.log(`已成功删除空 ${path}文件夹`);
            resolve()
        })
    })
}
// 新建文件夹
/**
 *  
 */
const mkdirTest = ()=>{
    return new Promise(resolve => {
        fs.mkdir('./test', { recursive: true }, (err, data)=>{
            if (err) {
                console.log(err)
            };
            console.log('新建文件夹成功')
            resolve()
        })
    })
}

// 读取html 内容
/**
 * 
 */
const readHtml = ()=>{
    return new Promise(resolve => {
        fs.readFile('./test.html', 'utf-8', (err, data)=>{
            if(err) {
                throw Error(err)
            }
            console.log('test.html 读取成功！--NO1')
            resolve(data)
        })
    })
}

// 写入css 和js
/**
 * 向文件中追加内容
 * @param {是文件名字} path 
 * @param {写入文件的内容} data 
 * @param {文件类型} type 
 * @author erlinger
 * @time 
 */
const appendFile = (path, data, type) => {
    return new Promise(resolve => {
        fs.appendFile(path, data, (err) => {
            if (err) {
                console.log(err)
            };
            console.log(`${type}数据已追加到文件`);
            resolve()
        });
    })
}
// 写一个html
const writeHtml = (path, data) => {
    return new Promise(resolve => {
        fs.writeFile(path, data, (err) =>{
            if(err) {
                console.log('err', err)
                return
            }
            console.log(`${path} 写入成功，功能结束!`);
            resolve() // 必须resolve 。不然 promise 就到此为止，调用该方法后面的代码将不执行
        })
    })
}

// 插件 方法入口
(async ()=>{
    console.log('==========================game-start=============================');
    await deleteDir('./test');
    console.log('我应该是等---删除文件夹后---才出现')

    await mkdirTest();
    console.log('我应该是在---文件夹新建成功---后出现！');

    let cssReg = /<style>[\s|\S]*?<\/style>/ig;
    let jsReg = /<script>[\s|\S]*?<\/script>/ig;
    let allStyleReg = /<\/style>[\s|\S]*?<style>/ig;
    let allScriptReg = /<\/script>[\s|\S]*?<script>/ig;
    let cssLink = &#39;<link rel="stylesheet" href="./test.css">&#39;;
    let jsrc = &#39;<script src="./test.js">&#39;;
    let styleCollection, scriptColletion;
    let cssContent = &#39;&#39;, jsContent = &#39;&#39;, htmlContentStr = &#39;&#39;;

    let originContent = await readHtml();
    styleCollection = originContent.match(cssReg);
    scriptColletion = originContent.match(jsReg);
    
    // 处理 css
    for (let i =0;i<styleCollection.length;i++) {
        cssContent += JSON.stringify(styleCollection[i]);
    }

    cssContent = cssContent.replace(/<style>/g,&#39;&#39;).replace(/<\/style>/g, &#39;&#39;).replace(/("")/g,&#39;&#39;)
    
    for (let i =0;i<scriptColletion.length;i++) {
        jsContent += JSON.stringify(scriptColletion[i]);
    }
    
    jsContent = jsContent.replace(/<script>/g,&#39;&#39;).replace(/<\/script>/g, &#39;&#39;)
    .replace(/<\/script>"*<script>/g, &#39;&#39;).replace(/("")/g,&#39;&#39;)
    
    await appendFile(&#39;./test/test.css&#39;, JSON.parse(cssContent), &#39;css&#39;);
    console.log(&#39;我应该是在---css写入成功---后出现！&#39;);

    await appendFile(&#39;./test/test.js&#39;, JSON.parse(jsContent), &#39;js&#39;);
    console.log(&#39;我应该是在---js写入成功---后出现！&#39;);

    htmlContentStr = originContent
    .replace(allStyleReg, &#39;&#39;)
    .replace(cssReg, cssLink)
    .replace(allScriptReg, &#39;&#39;)
    .replace(jsReg, jsrc);
    console.log(&#39;copyTest.html 文本已经格式化，准备写入&#39;);
    await writeHtml(&#39;./test/copyTest.html&#39;, htmlContentStr);

    console.log(&#39;==========================game-over=============================&#39;);
})()</style></_files.length>

node extract-js-css