webpack.config.js

const fs = require('fs')
const path = require('path')
const webpack = require('webpack')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin')
const TerserPlugin = require('terser-webpack-plugin')
const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin')
const dotenv = require('dotenv')

const envPath = path.resolve(__dirname, '.env')
if (fs.existsSync(envPath)) dotenv.config({ path: envPath })

const appPublic = path.resolve(__dirname, 'public')
const appBuild = path.resolve(__dirname, 'build')
const appSrc = path.resolve(__dirname, 'src')

const sources = {}
const pages = [
  {
    name: 'index',
    js: path.resolve(appSrc, 'index.jsx'),
    html: path.resolve(appPublic, 'index.html')
  }
]

pages.forEach(page => {
  sources[page.name] = page.js
})

const rewrites = pages.map(page => {
  const filename = path.basename(page.html)
  const name = path.basename(page.html, '.html')
  return {
    from: new RegExp(`\/${name}`),
    to: `/${filename}`
  }
})

rewrites.push({
  from: /./,
  to: '/'
})

const envs = { 'process.env': {} };
for (const key in process.env) {
  if (key.startsWith('REACT_APP_')) {
    envs['process.env'][key] = JSON.stringify(process.env[key]);
  }
}

module.exports = (env) => {
  process.env.NODE_ENV = env.NODE_ENV || 'development'
  const isProd = process.env.NODE_ENV === 'production'

  return {
    target: ['web', 'es5'],
    stats: 'errors-warnings',
    mode: env.NODE_ENV || 'development',
    performance: false,
    devtool: isProd ? false : 'source-map',
    entry: sources,
    output: {
      path: appBuild,
      publicPath: '/',
      filename: isProd ? 'js/[name].[contenthash:8].js' : 'js/[name].bundle.js',
      chunkFilename: isProd ? 'js/[name].[contenthash:8].chunk.js' : 'js/[name].chunk.js'
    },
    resolve: {
      extensions: ['.js', '.jsx', '.json']
    },
    plugins: [
      ...pages.map(page => {
        return new HtmlWebpackPlugin({
          inject: true,
          chunks: [page.name],
          template: page.html,
          filename: path.basename(page.html)
        })
      }),
      new webpack.DefinePlugin(envs),
      new InterpolateHtmlPlugin(HtmlWebpackPlugin, process.env),
      isProd && new MiniCssExtractPlugin({
        filename: 'css/[name].[contenthash:8].css',
        chunkFilename: 'css/[name].[contenthash:8].chunk.css'
      }),
      new CopyWebpackPlugin({
        patterns: [
          {
            from: appPublic,
            to: appBuild,
            filter: (filepath) => !filepath.endsWith('.html')
          }
        ]
      })
    ].filter(Boolean),
    module: {
      strictExportPresence: true,
      rules: [
        {
          enforce: 'pre',
          exclude: /@babel(?:\/|\\{1,2})runtime/,
          test: /\.(js|jsx|css)$/,
          use: 'source-map-loader'
        },
        {
          test: /\.(js|jsx)$/i,
          exclude: /node_modules/,
          use: 'babel-loader'
        },
        {
          test: /\.(s[ac]ss)$/i,
          use: [
            isProd ? MiniCssExtractPlugin.loader : 'style-loader',
            'css-loader',
            'sass-loader'
          ]
        },
        {
          test: /\.(css)$/i,
          use: ['style-loader', 'css-loader']
        },
        {
          test: /\.(bmp|png|jpe?g|gif)$/i,
          type: 'asset/resource'
        },
        {
          test: /\.svg$/i,
          use: ['@svgr/webpack', 'file-loader']
        }
      ]
    },
    optimization: {
      minimize: isProd,
      minimizer: [
        new TerserPlugin(),
        new CssMinimizerPlugin()
      ]
    },
    devServer: {
      compress: true,
      open: true,
      hot: true,
      liveReload: true,
      port: process.env.PORT || '3000',
      proxy: {
        '/api': 'http://localhost:3001'
      },
      static: {
        directory: appBuild
      },
      historyApiFallback: {
        disableDotRule: true,
        index: appPublic,
        rewrites
      },
      headers: {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': '*',
        'Access-Control-Allow-Headers': '*'
      }
    }
  }
}