[bastawhiz]

Be careful with this, though. If a promise is expected to resolve and it never does, and the promise needs to resolve or reject to clean up a global reference (like an event listener or interval), you'll create a memory leak. It's easy to end up with a leak that's almost impossible to track down, because there isn't something obvious you can grep for.

[hungryhobbit]

This is addressed at the end of the article:

  The catch

  You're relying on garbage collection, which is nondeterministic. You don't get to know when the suspended function is collected. For our use case, that's fine. We only need to know that it will be collected, and modern engines are reliable about that.

  The real footgun is reference chains. If anything holds a reference to the hanging promise or the suspended function's closure, the garbage collector can't touch it. The pattern only works when you intentionally sever all references.

[bastawhiz]

That should honestly be much higher up and much more clearly spelled out.