So given a promise P1, that would be any promises returned by doing P1.then() and any return values from calling Promise.all/Promise.race and passing P1.

Comment on attachment 8506353 [details] [diff] [review] Add a way to get the promises that depend on a given promise via PromiseDebugging Review of attachment 8506353 [details] [diff] [review]: ----------------------------------------------------------------- Very elegant! ::: dom/promise/PromiseCallback.h @@ +56,5 @@ > > void Call(JSContext* aCx, > JS::Handle<JS::Value> aValue) MOZ_OVERRIDE; > > + virtual Promise* GetDependentPromise() MOZ_OVERRIDE This 'virtual' can be removed. Same for the other overrides. ::: dom/promise/PromiseDebugging.cpp @@ +59,5 @@ > > +/* static */ void > +PromiseDebugging::GetDependentPromises(GlobalObject&, Promise& aPromise, > + nsTArray<nsRefPtr<Promise>>& aPromises) > +{ Might be a good idea to add a NS_WARN_IF(aPromise.mStatus != Promise::Pending, "Calling GetDependentPromises() on resolved Promise!") ::: dom/promise/tests/test_dependentPromises.html @@ +10,5 @@ > + <link rel="stylesheet" type="text/css" href="chrome://global/skin"/> > + <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/> > + <script type="application/javascript"> > + > + alert(Promise); huh? @@ +38,5 @@ > + > + arraysEqual(getDependentNames(p), ["q", "r", "s"], "deps for p"); > + arraysEqual(getDependentNames(q), ["s"], "deps for q"); > + arraysEqual(getDependentNames(r), ["t"], "deps for r"); > + arraysEqual(getDependentNames(r), ["t"], "deps for r"); s/r/s/g ::: dom/webidl/PromiseDebugging.webidl @@ +45,5 @@ > + * 3) Return values of Promise.race() if the given promise was passed in as > + * one of the arguments. > + * > + * Once a promise is settled, it will generally notify its dependent promises > + * and forget about them, so this is most useful on unsettled promises. Could you add a note that this function is not recursive.

> Might be a good idea to add a NS_WARN_IF(aPromise.mStatus != Promise::Pending, > "Calling GetDependentPromises() on resolved Promise!") I expect devtools to do just that in some cases if opened after the page has been running for a bit, so I'd rather not warn about it.... > huh? Oh, good catch! I forgot that was in the test when I was trying it out... > s/r/s/g Also good catch. > Could you add a note that this function is not recursive. Absolutely. How about: * Note that this function only returns the promises that directly depend on * p. It does not recursively return promises that depend on promises that * depend on p.

(In reply to Boris Zbarsky [:bz] from comment #3) > > > Could you add a note that this function is not recursive. > > Absolutely. How about: > > * Note that this function only returns the promises that directly depend > on > * p. It does not recursively return promises that depend on promises that > * depend on p. +1