webpack.config.js

const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ReactRefreshWebpackPlugin = require('@pmmmwh/react-refresh-webpack-plugin');

const isDevelopment = process.env.NODE_ENV === 'development';

module.exports = /** @type {webpack.Configuration} */ ({
  mode: isDevelopment ? 'development' : 'production',
  devtool: isDevelopment ? 'eval-source-map' : 'source-map',
  entry: path.resolve(__dirname, 'src', 'index'),
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'app.bundle.js',
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: path.resolve(__dirname, 'public', 'index.html'),
    }),
  ].concat(
    isDevelopment //
      ? []
      : [new ReactRefreshWebpackPlugin()],
  ),
  devServer: {
    static: {
      directory: path.join(__dirname, 'public'),
    },
    compress: true,
    port: 3000,
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        loader: 'babel-loader',
      },
    ],
  },
});