webpack.prod.js

const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');

module.exports ={
  mode: 'production',
  entry: './src/client/index.js',
  output: {
    libraryTarget: 'var',
    library: 'Client'
  },
  optimization: {
    minimizer: [new TerserPlugin({}), new OptimizeCSSAssetsPlugin({})]
  },
  module: {
    rules: [
      {
        test: '/\.js$/',
        exclude: /node_modules/,
        use:{
          loader: 'babel-loader'
        }
      },
      {
        test:/\.scss$/,
        use: [MiniCssExtractPlugin.loader, 'css-loader', 'sass-loader']
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './src/client/views/index.html',
      filename: './index.html'
    }),
    new MiniCssExtractPlugin({filename: '[name].css'}),
  ]
}