webpack.config.js

const webpack = require('webpack');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
const CompressionPlugin = require('compression-webpack-plugin');

const HtmlWebPackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const path = require("path");

const devMode = process.env.NODE_ENV !== 'production';

module.exports = {
    entry: "./src/index.jsx",
    output: {
        path: path.resolve(__dirname, 'build'),
        filename: './main.[contenthash].js',
        publicPath: '/'
    },
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: {
                    loader: "babel-loader"
                }
            },
            {
                test: /\.css$/,
                use: [
                    {
                        loader: MiniCssExtractPlugin.loader,
                        options: {
                            // you can specify a publicPath here
                            // by default it uses publicPath in webpackOptions.output
                            publicPath: '../',
                            hmr: process.env.NODE_ENV === 'development',
                        },
                  }, 'css-loader']
            },
            {
                test: /\.scss$/,
                use: [
                    {
                        loader: MiniCssExtractPlugin.loader,
                        options: {
                            // you can specify a publicPath here
                            // by default it uses publicPath in webpackOptions.output
                            publicPath: '../',
                            hmr: process.env.NODE_ENV === 'development',
                        },
                    }, 'css-loader', 'sass-loader']
            },
            {
                test: /\.(ico|jpg|JPG|jpeg|png|gif|eot|otf|webp|svg|pdf|ttf|woff|woff2|mp4)(\?.*)?$/,
                use: [
                    {
                        loader: 'url-loader',
                        options: {
                            limit: 2000
                        }
                    }
                ]
            }
        ]
    },
    devServer: {
        historyApiFallback: true,
    },
    optimization: {
        minimizer: [new UglifyJsPlugin()],
        namedModules: false,
        namedChunks: false,
        nodeEnv: 'production',
        flagIncludedChunks: true,
        occurrenceOrder: true,
        sideEffects: true,
        usedExports: true,
        concatenateModules: true,
        noEmitOnErrors: true,
        checkWasmTypes: true,
        minimize: true,
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename: '[name].[hash].css',
            chunkFilename: '[id].[hash].css'
        }),
        new HtmlWebPackPlugin({
            template: "./src/index.html",
            favicon: "./src/assets/images/logo.png"
            // filename: "./index.html"
        }),
        new webpack.DefinePlugin({ // <-- key to reducing React's size
            'process.env': {
                'NODE_ENV': JSON.stringify('production')
            }
        }),
        new CompressionPlugin({
            test: /\.js(\?.*)?$/i
        })
    ]
};