when does bluebird log unhandled rejections?

Question

I'm having trouble understanding when bluebird will log an unhandled rejection versus dropping it. I guess this has something to do with what the documentation calls "the second turn" but I'm not clear what that means.

Promise.reject(new Error("oops"))

-> no log

Promise.reject(new Error("oops")).then(function() {})

-> stack trace logged

Promise.method(function() { throw new Error("oops"); })()

-> no log

Promise.method(function() { throw new Error("oops"); })().then(function() {})

-> stack trace logged

Promise.promisify(function(k) { k(new Error("oops"), null); })()

-> stack trace logged

I am in the middle of converting some code to bluebird promises and I am getting rejections dropped all over the place. (Okay, first it was #100, I'm an idiot.) I guess I will use .promisify rather than .method to get past my current silent failures but I'm frightened that there might be other circumstances where I'll miss a thrown error.

Answer 1

Unhandled rejections should be logged whenever there's an unhandled rejection, so 1 and 3 are bugs because you don't have any handlers for the rejection registered by the "start of the second turn".