Are promise callbacks sent to Event queue?

Question

Consider the following code:

        function wait(ms) {
            var deferred = $.Deferred();
            setTimeout(deferred.resolve, ms);
            return deferred.promise();
        }

        var starter, promiseOne;
        starter = $.Deferred();
        promiseOne = starter.then(function () {
            console.log("Calling promiseOne");
            return wait(2000);
        }).done(function () {
            console.log('promiseOne done');
        });
        starter.resolve();

        var now=new Date().getTime();
        var stop=now+5000;
        while (stop>new Date().getTime()){}
        console.log('timeout finished');

By running it, I am getting the following results:

Calling promiseOne
timeout finished
promiseOne done

I was thinking that promise callbacks are sent to Event queue, so I was expecting these results:

timeout finished
Calling promiseOne
promiseOne done

If not sending to Event queue,I 'd expect:

Calling promiseOne
promiseOne done
timeout finished

Could someone explain to me why am I getting the first triad?

P.S. By replacing then with done, I am getting:

Calling promiseOne
promiseOne done
timeout finished

Answer 1

The jQuery implementation of the Promises isn't ECMASCRIPT compliant, for example, jQuery promises (actually) aren't resolved at the next event loop. jQuery promises will be es-compliant with the upcoming third version: jQuery.Deferred is now Promises/A+ compatible.

Note: did you try to run starter.resolve() in a async function? for example: window.setTimeout(starter.resolve, 0); Doing that your test-case should work as expected. By the way, this isn't a Promise-bug but a simple jQuery-bad-implementation, remember that jQuery was born some year before the Promise specification

In order to reply at:

Are promise callbacks sent to Event queue?

Promise callbacks are simple javascript callbacks, so, as each simple javascript callback, even promise callbacks are attached to the event loop.