webpack.config.js

const HtmlWebPackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const devMode = false//process.env.NODE_ENV !== 'production'

module.exports = {
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: "/node_modules/",
                use: {
                    loader: "babel-loader"
                }
            },
            {
                test: /\.(s*)css$/,
                use: [
                    devMode ? 'style-loader' : MiniCssExtractPlugin.loader,
                    'css-loader',
                    'sass-loader',
                ],
            },
            {
                test: /\.html$/,
                use: {
                    loader: "html-loader"
                }
            }
        ]
    },
    plugins: [
        new MiniCssExtractPlugin({
            // filename: devMode ? '[name].css' : '[name].[hash].css',
             filename: devMode ? '[name].css' : '[hash].css',
            chunkFilename: devMode ? '[id].css' : '[id].[hash].css',
        }),
        new HtmlWebPackPlugin({
            template: "./src/index.html",
            filename: "./index.html"
        }),

    ]
}