webpack.prod.js

const path = require('path');
const webpack = require('webpack');
const TerserPlugin = require('terser-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
// const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;

const dotenv = require('dotenv').config({ path: `${__dirname}/.env` }).parsed;

module.exports = {
  target: 'web',

  entry: [
    'babel-polyfill',
    './src/index.js',
  ],
  output: {
    path: path.resolve(__dirname, 'build'),
    publicPath: dotenv.PUBLIC_PATH,
    filename: 'static/js/[name].[chunkhash:8].js',
    chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',
  },

  mode: 'production',

  resolve: {
    modules: [
      'src',
      'node_modules',
    ],
  },

  optimization: {
    splitChunks: {
      chunks: 'all',
    },
    minimizer: [
      new TerserPlugin(),
      new OptimizeCSSAssetsPlugin(),
    ],
  },

  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'babel-loader',
      },
      {
        test: /\.(sa|sc|c)ss$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
          },
          'css-loader',
          'postcss-loader',
        ],
      },
      {
        test: /\.(png|jpg|gif)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: 'static/[path][name].[hash:8].[ext]',
              context: 'src',
            },
          },
        ],
      },
    ],
  },

  plugins: [
    new HtmlWebpackPlugin({
      inject: true,
      template: path.resolve(__dirname, 'public/index.html'),
    }),
    new webpack.DefinePlugin({
      'process.env': JSON.stringify({
        ...dotenv,
        NODE_ENV: 'production',
      }),
    }),
    new MiniCssExtractPlugin({
      filename: 'static/css/[name].[hash:8].css',
      chunkFilename: 'static/css/[id].[hash:8].css',
    }),
    // new BundleAnalyzerPlugin(),
  ],
};