ECMAScript doesn't have cancellable promises, but then again it doesn't have observables or async iterators either. Native observables are less capable in this

ECMAScript doesn't have cancellable promises, but then again it doesn't have observables or async iterators either. Native observables are less capable in this regard than native promises since they're non existent yet. Bluebird promises are cancellable. For what it's worth I've discussed this personally with Meijer (it's Meijer, not Meijers) and he agrees that cancellable promises are not problematic one bit. Promises, observables and other async primitives all co-exist just fine :)