-`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.
-`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.
- Runtime errors are now represented by objects. You must call tostring on rejection values before assuming they are strings (this was always good practice, but is required now).
- Yielding is now allowed in `Promise.new`, `andThen`, and `Promise.try` executors.
- Errors now have much better stack traces due to using `xpcall` internally instead of `pcall`.
- Stack traces will now be more direct and not include as many internal calls within the Promise library.
- Chained promises from `resolve()` or returning from andThen now have improved rejection messages for debugging.
-`Promise.async` has been renamed to `Promise.defer` (`Promise.async` references same function for compatibility)
- Promises now have a `__tostring` metamethod, which returns `Promise(Resolved)` or whatever the current status is.
-`Promise:timeout()` now rejects with a `Promise.Error(Promise.Error.Kind.TimedOut)` object. (Formerly rejected with the string `"Timed out"`)
- Attaching a handler to a cancelled Promise now rejects with a `Promise.Error(Promise.Error.Kind.AlreadyCancelled)`. (Formerly rejected with the string `"Promise is cancelled"`)
- Improved test coverage for asynchronous and time-driven functions
### Fixed
- Changed `Promise.is` to be safe when dealing with tables that have an `__index` metamethod that creates an error.
-`Promise.delay` resolve value (time passed) is now more accurate (previously passed time based on when we started resuming threads instead of the current time. This is a very minor difference.)
