Q fails to perform circularity check

[marijaselakovic]

Hello,
It seems that Q doesn't detect circular promise chains and in some situations, it can go to an infinite loop that never terminates. I encountered the following piece of code:

var Promise = require('q');
var p1 = new Promise(function (resolve, reject) {
    resolve(19)
});
var p2 = p1.then(function (v) {
    return p2;
});
var p3 = p2.then(function (v) {
    return v
})

First callback to then returns the promise (p2) that is actually returned by then itself, which causes a chaining cycle for p2. This test never terminates. Maybe you would like to check this out.

[gustavlsouz]

I think it can help.

https://github.com/petkaantonov/bluebird/wiki/Error:-circular-promise-resolution-chain