webpack.config.js

const HtmlWebpackPlugin = require("html-webpack-plugin");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const BundleAnalyzerPlugin = require("webpack-bundle-analyzer")
  .BundleAnalyzerPlugin;

const htmlPlugin = new HtmlWebpackPlugin({
  template: "./src/index.html",
  filename: "./index.html"
});

const cssPlugin = new MiniCssExtractPlugin({
  filename: "[name].css",
  chunkFilename: "[id].css"
});

module.exports = {
  entry: ["@babel/polyfill", "./src"],
  output: {
    publicPath: "/"
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader"
        }
      },
      {
        test: /\.(css|scss)$/,
        use: ["style-loader", "css-loader", "sass-loader"]
      }
    ]
  },
  devServer: {
    historyApiFallback: true
  },
  optimization: {
    minimizer: [
      new UglifyJsPlugin({
        cache: true,
        parallel: true,
        sourceMap: false
      }),
      new OptimizeCSSAssetsPlugin({})
    ]
  },
  plugins: [htmlPlugin, cssPlugin]
};