babel.config.js

module.exports = {
  presets: [
    ['@babel/preset-env', {
      targets: { node: '8' },
      /*
       * useBuiltIns configures how @babel/preset-env handles polyfills.
       * useBuiltIns: 'usage' - adds specific imports for polyfills when they are used in each file.
       * useBuiltIns: 'entry' - adds individual requires to different core-js entry points based on environment.
       * useBuiltIns: false - does not add polyfills automatically per file
       * 
       * Note:
       * This library (serverless-pg) does not currently require polyfills
       * but it may in the future. When a polyfill for node 8 is needed,
       * a polyfill dependency will need to be added (such as
       * @babel/polyfill or core-js/stable.
       * See https://babeljs.io/docs/en/babel-polyfill).
       * 
       */
      useBuiltIns: 'usage',
      /*
       * corejs - This option only has an effect when used alongside
       * useBuiltIns: usage or useBuiltIns: entry, and ensures
       * @babel/preset-env injects the correct imports for your
       * core-js version.
       */
      corejs: 2,
      /*
       * modules: 'auto' (default) which will automatically select 'false' if the current 
       * process is known to support ES module syntax, or "commonjs" otherwise.
       * When targeting node v8, transformations from ES module syntax to module.exports
       * will occur.
       */
      modules: 'auto',
    }],
  ],
};