Example config for webpack not generating sourcemaps

no-source-map.webpack.js

const path = require('path');
const webpack = require('webpack');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
const HardSourceWebpackPlugin = require('hard-source-webpack-plugin');
const ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
  mode: 'production',
  entry: {
    'app': [
      './static/js/react/app/app.js'
    ]
  },
  output: {
    path: __dirname + '/static/dist',
    filename: '[name].bundle.js',
    sourceMapFilename: '[file].map',
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        options: {
          cacheDirectory: true
        },
        include: [
          path.resolve(__dirname, 'static/js/react')
        ],
        exclude: path.resolve(__dirname, 'node_modules')
      },
      {
        test: /\.css$/,
        use: ExtractTextPlugin.extract({
          fallback: "style-loader",
          use: [
            {
              loader: 'css-loader',
              options: {
                modules: true,
                localIdentName: '[local]_[hash:base64:5]',
                sourceMap: false,
              }
            }
          ]
        }),
        include: [
          path.resolve(__dirname, 'static/js/react'),
        ],
        exclude: path.resolve(__dirname, 'node_modules')
      },
      {
        test: /\.css$/,
        use: ExtractTextPlugin.extract({
          fallback: "style-loader",
          use: [
            {
              loader: 'css-loader',
              options: {
                sourceMap: false,
              }
            }
          ]
        }),
        include: [
          path.resolve(__dirname, 'node_modules/bootstrap'),
        ],
        exclude: /node_modules\/(?!(bootstrap)\/).*/
      },
    ]
  },
  plugins: [
    new webpack.ProvidePlugin({
      $: 'jquery',
      jQuery: 'jquery',
      'window.jQuery': 'jquery',
      Popper: ['popper.js', 'default'],
      // In case you imported bootstrap plugins individually, you must also require them here:
      // Util: "exports-loader?Util!bootstrap/js/dist/util",
      // Dropdown: "exports-loader?Dropdown!bootstrap/js/dist/dropdown",
    }),
    new ExtractTextPlugin("[name]-styles.css"),
    new UglifyJSPlugin({
        sourceMap: true,
        parallel: true,
        cache: true
    }),
    new webpack.SourceMapDevToolPlugin({
      append: "\n//# sourceMappingURL=http://localhost:8081/static/dist/[url]",
      filename: '[file].map',
      exclude: /node_modules\/(?!(bootstrap)\/).*/
    }),
    new HardSourceWebpackPlugin(),
  ],
  externals: {
    "jquery": "jQuery",
  }
};