gistfile1.js

var bluebird = require('bluebird');
var request = require('request');
bluebird.promisifyAll(request);
bluebird.longStackTraces();

var helper = bluebird.coroutine(function*() {
  yield request.getAsync('http://google.com/');
  throw new Error('something unexpected happened');
});

bluebird.coroutine(function*() {
  yield helper();
})();