Promise v4.0.0

[4.0.0]

Changed

• Promise:finally no longer observes a rejection from a Promise. Calling Promise:finally is mostly transparent now.
  • The Promise returned by Promise:finally resolves or rejects with whatever the parent Promise resolved or rejected with. It will be cancelled if the parent Promise is cancelled.
  • The value returned from the finally handler is discarded now.
  • If the value returned from the finally handler is a Promise, we wait for it to resolve, but we do not use its value.
  • If the value returned from the finally handler is a Promise and it rejects, finally returns the new rejected value.
• Promise:finally no longer counts as a consumer of the parent Promise for cancellation purposes. If all consumers are cancelled and the only remaining callbacks are finally handlers, the Promise is now cancelled.
• The Promise executor thread is now closed with coroutine.close when the Promise is cancelled.
• The Promise executor thread is now closed after the Promise settles (calling resolve or reject).
• Callbacks enqueued with andThen and catch are now dequeued if the Promise returned by andThen/catch is cancelled.
• Calling andThen or catch on an already-cancelled Promise now returns a cancelled Promise instead of returning a rejected Promise
• :await, :expect, and :awaitStatus are no longer backed by BindableEvents, and now use the task library directly, so performance should be better.

Removed

• Promise:done and its associated members have been removed.