npm init -y

 npm i babel-core babel-loader babel-preset-es2015 webpack -D && npm i -g webpack-cli

 const path = require('path');

 module.exports = {

     // 入口

     // 一旦package.json里面配置了webpack --mode=production,下面的mode:'production'就不必了

     // mode:'production',

     entry:path.resolve(__dirname,'app.js'),

     output: {

         // 出口重命名js

         filename: 'bundle.js',

         // 出口文件夹名

         path:path.resolve(__dirname,'build'),

     },

     module:{

         rules:[

             {

                 test:/(\.jsx|\.js)$/,

                 use:{

                     loader:"babel-loader",

                     options:{

                         presets:[

                             "env"

                         ]

                     }

                 },

                 exclude:path.resolve(__dirname,"node_modules"),

                 include:path.resolve(__dirname,"src")

             }

         ]

     }

 }