webpack

1、安装

cd mypack --------//进入项目目录
npm init ------------//初始化项目
npm i webpack -D ------//安装webpack
npm i webpack-cli -D --------//安装脚手架

2、配置webpack.config.js

//webpack是node写出来的  node写法  path  node内置语法
let path = require('path');
module.exports = {
  devServer:{
    port:3000,
    progress:true,
    contentBase:'./build',
    compress:true,
}
  mode:'development', //模式  默认两种 production（生产）  development（开发-非压缩）
  entry:'./src/index.js',  //入口
  output:{
    filename:'bundle.js',   //打包后的文件名
    path:path.resolve(__dirname,'build'),  //路径必须是一个绝对路径 __dirname是指当前目录,不写也可以
  }
}

package.json

{
  "name": "mypack",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "dev":"webpack-dev-server"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "webpack": "^4.43.0",
    "webpack-cli": "^3.3.12"
  }
}

yarn add webpack-dev-server -D
npx webpack-dev-server