exports.createPromiseCallback = createPromiseCallback; function createPromiseCallback() { var cb; if (!global.Promise) { cb = function() {}; cb.promise = {}; Object.defineProperty(cb.promise, 'then', { get: throwPromiseNotDefined }); Object.defineProperty(cb.promise, 'catch', { get: throwPromiseNotDefined }); return cb; } var promise = new global.Promise(function(resolve, reject) { cb = function(err, data) { if (err) return reject(err); return resolve(data); }; }); cb.promise = promise; return cb; } function throwPromiseNotDefined() { throw new Error( 'Your Node runtime does support ES6 Promises. ' + 'Set "global.Promise" to your preferred implementation of promises.'); }