webpack 优化

yarn add webpack webpack-cli html-webpack-plugin @babel/core babel-loader @babel/preset-env @babel/preset-react -D

webpack.config.js

let path = require('path')
let HtmlWebpackPlugin = require('html-webpack-plugin')


module.exports = {
    mode: 'development',
    entry: './src/index.js',
    output: {
        filename: 'main.js',
        path: path.resolve(__dirname, 'dist')
    },
    module: {
      rules: [
          {
              test: /\.js$/,
              use: {
                  loader: 'babel-loader',
                  options: {
                      presets: [
                          '@babel/preset-env',
                          '@babel/preset-react'
                      ]
                  }
              }
          },
      ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: './src/index.html',
            filename: 'index.html'
        }),
    ]
}