webpack.config.js

const HtmlWebpackPlugin = require('html-webpack-plugin'); //installed via npm
const webpack = require('webpack'); //to access built-in plugins
const path = require('path');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");

module.exports = {
    entry: {
        bundle: "./src/entry.js",
    },
    output: {
        path: path.resolve(__dirname, './public'),
        // Save with the key from the entry section. Ie bundle.js, vendor.js
        // Chunkhash is a hash of the contents of the file.
        filename: '[name].min.js'
    },
    optimization: {
        splitChunks: {
            cacheGroups: {
                styles: {
                    name: 'styles',
                    test: /\.css$/,
                    enforce: true
                }
            }
        },
        // Minify css. Setting optimization.minimizer overrides the defaults provided by webpack,
        // we also need to specify a JS minimizer.
        minimizer: [
            new UglifyJsPlugin({
                cache: true,
                parallel: true,
                sourceMap: true // set to true if you want JS source maps
            }),
            new OptimizeCSSAssetsPlugin({})
        ]
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: ['@babel/preset-env', "@babel/preset-react"]
                    }
                }
            },
            {
                test: /\.txt$/,
                use: 'raw-loader'
            },
            {
                test: /\.css$/,
                // Order is important! Loaders are applied from right to left
                use: [
                    MiniCssExtractPlugin.loader,
                    'css-loader'
                ]
            },
            {
                test: /\.less$/,
                use: [
                    MiniCssExtractPlugin.loader,
                    'css-loader',
                    'less-loader'
                ]
            },
            {
                test: /\.(jpeg|png|gif|svg)$/,
                use: [
                    {
                        loader: 'url-loader',
                        options: { limit: 40000 },

                    },
                    'image-webpack-loader'
                ]
            }
        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: path.resolve(__dirname, 'src', 'index.html'),
            filename: './index.html'

        }),
        new MiniCssExtractPlugin({
            filename: '[name].min.css'
        }),
        new webpack.ProvidePlugin({
            "_": "underscore",
            "Backbone": "backbone"
        })
    ],
    devServer: {
        port: 8081,
        contentBase: path.join(__dirname, 'public')
    },
};