unhandledRejection does not provide promise.stack

[arikwex]

(Praying I did a good dupe check before submitting this)

I'm running a node process that catches any unhandledRejections. I'd like to hunt down all offenders in my app by viewing promise.stack when an unhandledRejection is emitted. Sample app:

const Q = require('q');
Q.longStackSupport = true;

// Unhandled rejection for node
process.on('unhandledRejection', (reason, promise) => {
  console.log(`Unhandled rejection reason: ${reason}`);
  console.log(`Unhandled rejection has stack: ${promise.stack ? 'true' : 'false'}`);
});

// Create an unhandled rejection
const d = Q.defer();
d.reject('denied!');
console.log(`Promise reason: ${d.promise.source.exception}`);
console.log(`Promise has stack: ${d.promise.stack ? 'true' : 'false'}`);

Output:

Promise reason: denied!
Promise has stack: true
Unhandled rejection reason: denied!
Unhandled rejection has stack: false

My issue is that the unhandledRejection event provides a promise that does not contain the stack information. Am I doing something wrong here? or is this working as intended?

[kriskowal]

Try Q.reject(new Error("denied!")). Reject is analogous to throw and you only get a stack trace if you use an Error object instance.