webpack-prod.config.js

const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CleanWebpackPlugin = require("clean-webpack-plugin");
module.exports = {
  mode: "production",
  entry: ["babel-polyfill", "./src/index.js"],
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /(node_modules|bower_components)/,
        loader: "babel-loader",
        options: { presets: ["env"], plugins: ["transform-class-properties"] }
      },
      {
        test: /\.s[ac]ss$/i,
        use: [
          // Creates `style` nodes from JS strings
          'style-loader',
          // Translates CSS into CommonJS
          'css-loader',
          // Compiles Sass to CSS
          'sass-loader',
          'postcss-loader'
        ],
      },
      {
        test: /\.css$/,
        use: ["style-loader", "css-loader", 'postcss-loader']
      },
      {
        test: /\.(png|jpg|jpeg|gif|svg|pdf)/,
        exclude: /(node_modules|bower_components)/,
        loader: "file-loader",
        options: {
          name: "/images/[name].[ext]"
        }
      }
    ]
  },
  resolve: { extensions: ["*", ".js", ".jsx"] },
  output: {
    path: __dirname,
    filename: "bundle.js"
  },

  plugins: [
    new HtmlWebpackPlugin({
      title: "React Starter",
      template: path.resolve(__dirname, "./template/index.html")
    })
  ]
};