webpack.config.js

const HtmlWebpackPlugin = require('html-webpack-plugin');
var EXCLUDE = /node_modules|bower_components/

const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin")
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");


const path = require('path')

module.exports = {
    devtool: 'eval-cheap-module-source-map',
    entry: {
        vendor: ['./src/index.js'],
    },
    output: {
        filename: '[name].js',
        path: path.resolve(__dirname, 'dist')
    },
    devServer: {
        contentBase: './dist'
    },
    module: {
        rules: [{
                test: /\.js$/,
                loader: 'babel-loader',
                exclude: EXCLUDE
            },
            {
                test: /\.scss|css$/,
                use: [
                    MiniCssExtractPlugin.loader,
                    'css-loader',
                    "sass-loader" // compiles Sass to CSS, using Node Sass by default
                ]
            },
            {
                test: /\.(png|svg|jpg|gif)$/,
                use: [
                    'file-loader'
                ]
            },
        ]
    },
    plugins: [
        new MiniCssExtractPlugin({
            // Options similar to the same options in webpackOptions.output
            // both options are optional
            filename: "[name].css"
        }),

        new HtmlWebpackPlugin({
            template: 'index.html'
        }),
    ],
    optimization: {
        minimizer: [
            new UglifyJsPlugin({
                cache: true,
                parallel: true,
                sourceMap: true // set to true if you want JS source maps
            }),
            new OptimizeCSSAssetsPlugin({})
        ]
    },
}