webpack.server.config.js

const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: { server: './server.ts' },
  resolve: { 
    extensions: ['.js', '.ts'],
    fallback: {
      "util": require.resolve("util/")
    }
   },
  target: 'node',
  mode: 'none',
  // this makes sure we include node_modules and other 3rd party libraries
  externals: [/node_modules/],
  output: {
    path: path.join(__dirname, 'dist'),
    filename: '[name].js'
  },
  module: {
    rules: [
      { test: /\.ts$/, loader: 'ts-loader' },
      {
        test: /\.(sass|less|css)$/,
        use: [
            "style-loader", // 3. Inject styles into DOM
            "css-loader", // 2. Turns css into commonjs
            "sass-loader", // 1. Turns sass into css
        ]
      },
      { test: /\.txt$/, use: 'raw-loader' }
    ]
  },
  plugins: [
    // Temporary Fix for issue: https://github.com/angular/angular/issues/11580
    // for 'WARNING Critical dependency: the request of a dependency is an expression'
    new webpack.ContextReplacementPlugin(
      /(.+)?angular(\\|\/)core(.+)?/,
      path.join(__dirname, 'src'), // location of your src
      {} // a map of your routes
    ),
    new webpack.ContextReplacementPlugin(
      /(.+)?express(\\|\/)(.+)?/,
      path.join(__dirname, 'src'),
      {}
    )
  ]
};