I want see all the unresolved states (if possible all the log of deferreds: init, unresolved, resolved/rejected states). Is there any mechanism for it?
Something like: Q.getAllDeferreds(), or Q.getLog()
Assuming "q" ...
See the "Progress Notification" section and the bit about "deferred.notify" in the "Using Deferreds" section - here.
But please note that it says (as one might expect) "not all promises will implement progress notifications", so unless your worker module provides for notifications, then there's nothing you can do about it on the promise-consuming side. You can set up a progress handler in a .then(), but it will not fire unless the module calls deferred.notify().
Of course, if the worker module is of your own construction (or otherwise under your control) then you can modify it to provide notifications.
Deferred implementation (I'm the author) offers things like unresolved promises monitor and promise "usage statistics", check https://github.com/medikoo/deferred#monitoring-unresolved-promises