code: function getDefaultWorker() {
    if (environment.platform == 'browser') {
      // test whether the browser supports all features that we need
      if (typeof Blob === 'undefined') {
        throw new Error('Blob not supported by the browser');
      }
      if (!window.URL || typeof window.URL.createObjectURL !== 'function') {
        throw new Error('URL.createObjectURL not supported by the browser');
      }
  
      // use embedded worker.js
      var blob = new Blob([require('./generated/embeddedWorker')], {type: 'text/javascript'});
      return window.URL.createObjectURL(blob);
    }
    else {
      // use external worker.js in current directory
      return __dirname + '/worker.js';
    }
  }
docs: get the default worker script