webpack.config.js

const path = require('path');

module.exports = {
  entry: './src/index.ts',
  target: "node",
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        use: {
          loader: 'ts-loader',
          options: {
            compilerOptions: {
              noEmit: false
            }
          }
        },
        exclude: /node_modules/,
      },
    ],
  },
  resolve: {
    extensions: [ '.tsx', '.ts', '.js' ],
    // see https://stackoverflow.com/a/59267337/2489334
    alias: {
      'universal-user-agent': path.resolve(__dirname, 'node_modules/universal-user-agent/dist-node/index.js')
    }
  },
  output: {
    filename: 'index.js',
    path: path.resolve(__dirname, 'dist'),
  },
};