webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
const TerserPlugin = require('terser-webpack-plugin');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');

module.exports = (env, argv) => {
  const isProduction = argv.mode === 'production';

  const config = {
    entry: './src/index.js',
    output: {
      path: path.resolve(__dirname, 'dist'),
      filename: '[name].[contenthash].js',
      clean: true,
      publicPath: '/',
    },
    module: {
      rules: [
        {
          test: /\.(js|jsx)$/,
          exclude: /node_modules/,
          use: {
            loader: 'babel-loader',
            options: {
              presets: ['@babel/preset-env', '@babel/preset-react']
            }
          }
        },
        // CSS 규칙 추가 (만약 CSS 파일을 사용한다면)
        {
          test: /\.css$/,
          use: ['style-loader', 'css-loader'],
        },
      ]
    },
    optimization: {
      minimize: isProduction,
      minimizer: [
        new TerserPlugin({
          terserOptions: {
            parse: {
              ecma: 8,
            },
            compress: {
              ecma: 5,
              warnings: false,
              comparisons: false,
              inline: 2,
            },
            mangle: {
              safari10: true,
            },
            output: {
              ecma: 5,
              comments: false,
              ascii_only: true,
            },
          },
          parallel: true,
        }),
        new CssMinimizerPlugin(),
      ],
      splitChunks: {
        chunks: 'all',
      },
    },
    devServer: {
      static: {
        directory: path.join(__dirname, 'public'),
      },
      historyApiFallback: true,
      open: true,
      hot: true,
      port: 3000,
    },
    resolve: {
      extensions: ['.js', '.jsx'],
    },
    plugins: [
      new HtmlWebpackPlugin({
        template: './public/index.html',
      }),
    ],
    devtool: isProduction ? 'source-map' : 'eval-source-map',
  };

  if (env.analyze) {
    config.plugins.push(new BundleAnalyzerPlugin());
  }

  return config;
};