webpack.config.js

const path = require('path');
const webpack = require('webpack');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CompressionPlugin = require('compression-webpack-plugin');
const ManifestPlugin = require('webpack-manifest-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

require('dotenv').config();

/*
const dotenv = require('dotenv');
dotenv.config();
*/

const isDev = (process.env.ENV === 'development');
const entry = ['./src/frontend/index.js'];

if (isDev) entry.push('webpack-hot-middleware/client?path=/__webpack_hmr&timeout=20000&reload=true')

module.exports = {
  mode: isDev ? 'development' : 'production',
  entry, // the same at entry: entry;
  output: {
    path: path.resolve(__dirname, 'src/server/public'),
    filename: isDev ? 'assets/app.js' : 'assets/app-[hash].js',
    publicPath: '/',
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  optimization: {
    minimize: true,
    minimizer: [new TerserPlugin()],
    splitChunks: {
      chunks: 'async',
      name: true,
      cacheGroups: {
        vendors: {
          name: 'vendors',
          chunks: 'all',
          reuseExistingChunk: true,
          priority: 1, // 1 (max) to 10
          filename: isDev ? 'assets/vendor.js' : 'assets/vendor-[hash].js',
          enforce: true,
          test(module, chunks) {
            const name = module.nameForCondition && module.nameForCondition();
            return chunks.some(chunk => chunk.name !== 'vendors' && /[\\/]node_modules[\\/]/.test(name));
          },
        },
      },
    },
  },
  module: {
    rules: [
      {
        enforce: 'pre', // to execute before
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        loader: 'eslint-loader',
      },
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
        },
      },
      {
        test: /\.(s*)css$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
          },
          'css-loader',
          'sass-loader'
        ]
      },
      {
        test: /\.(png|gif|jpg)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: 'assets/[hash].[ext]',
            },
          },
        ]
      }
    ],
  },
  devServer: {
    historyApiFallback: true,
  },
  plugins: [
    isDev ? () => { } :
      new CleanWebpackPlugin({
        cleanOnceBeforeBuildPatterns: path.resolve(__dirname, 'src/server/public')
      }),
    isDev ? new webpack.HotModuleReplacementPlugin() : () => { },
    new MiniCssExtractPlugin({
      filename: isDev ? 'assets/app.css' : 'assets/app-[hash].css',
    }),
    isDev ? () => { } :
      new CompressionPlugin({
        test: /\.js$|\.css$/,
        filename: '[path].gz',
      }),
    isDev ? () => { } : new ManifestPlugin(),
  ],
};