webpack.config.js

const LiveReloadPlugin = require('webpack-livereload-plugin');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");

module.exports = {
    mode: 'development',
    watch: true,
    entry: './src',
    module: {
        rules: [
            {
                test: /\.m?js$/,
                exclude: /(node_modules|bower_components)/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: ['@babel/preset-env'],
                        plugins: [
                            '@babel/plugin-proposal-object-rest-spread',
                            '@babel/plugin-proposal-class-properties'
                        ]
                    }
                }
            },
            {
                test: /\.css/,
                use: [
                    MiniCssExtractPlugin.loader, // creates style nodes from JS strings
                    "css-loader", // translates CSS into CommonJS
                    "sass-loader" // compiles Sass to CSS, using Node Sass by default
                ]
            },
            {
                test: /\.scss$/,
                use: [
                    MiniCssExtractPlugin.loader, // creates style nodes from JS strings
                    "css-loader", // translates CSS into CommonJS
                    "sass-loader" // compiles Sass to CSS, using Node Sass by default
                ]
            }
        ]
    },
    plugins: [
        new LiveReloadPlugin(),
        new MiniCssExtractPlugin({
            // Options similar to the same options in webpackOptions.output
            // both options are optional
            filename: "main.css",
            chunkFilename: "1.css"
        })
    ]
};