`AsyncPipe.transform` will never return `undefined`, even when passed
`undefined` in input, in contrast with what was declared in the
overloads.
Additionally the "actual" method signature can be updated to match the
most generic case, since the implementation does not rely on wrappers
anymore.
BREAKING CHANGE:
The async pipe no longer claims to return `undefined` for an input that
was typed as `undefined`. Note that the code actually returned `null` on
`undefined` inputs. In the unlikely case you were relying on this,
please fix the typing of the consumers of the pipe output.
PR Close#37447
`AsyncPipe` only uses `WrappedValue` when the latest value from the `Promise` or `Observable` is different from the previous one. This is already enough to trigger change detection so the `WrappedValue` is not necessary.
Fixes#29927
BREAKING CHANGE:
This change could result in ExpressionChangedAfterItHasBeenChecked errors that
were not detected before. The error could previously have gone undetected
because two WrappedValues are considered "equal" in all cases for the purposes
of the check, even if their respective unwrapped values are not.
Additionally, `[val]=(observable | async).someProperty` will no longer
trigger change detection if the value of `someProperty` is identical to
the value in the previous emit. If you need to force change detection,
either update the binding to use an object whose reference changes or
subscribe to the observable and call markForCheck as needed.
PR Close#36633
Andrea Canciani
Joey Perrott
Andrew Scott
Danny Skoog
Misko Hevery
Trotyl Yu
Jason Aden