npm i -D webpack-bundle-analyzer core-js babel-loader

webpack.config.js
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin; 

module.exports = {
    entry: './src/index.js',
    output: {
        filename: 'main.js',
    },
    // mode: 'production', // 或者 'production'
    module: {
        rules: [
            {
            test: /\.js$/i,
            exclude: /node_modules/,
            use: [
                  {  
                    loader: 'babel-loader', // 需要并行处理的loader  
                    // ... 其他babel-loader配置  
                  }, 
            ]
        }
    ]
    },
    plugins: [
        new BundleAnalyzerPlugin({})
    ]
}

src/index.js
import 'core-js/stable'

let a = 1
a+=1

执行完打包后会立即打包在线依赖图