ErrorCallbackHandler typedef Null safety

ErrorCallbackHandler = AsyncError? Function(Zone self, ZoneDelegate parent, Zone zone, Object error, StackTrace? stackTrace)

The type of a custom Zone.errorCallback implementation function.

Receives the Zone that the handler was registered on as self, a delegate forwarding to the handlers of self's parent zone as parent, and the current zone where the error was uncaught as zone, which will have self as a parent zone.

The error and stackTrace are the error and stack trace passed to Zone.errorCallback of zone.

The function should return either null if it doesn't want to replace the original error and stack trace, or an AsyncError containing a replacement error and stack trace which will be used to replace the originals.

The error callback handler must not throw.

The function must only access zone-related functionality through self, parent or zone. It should not depend on the current zone (Zone.current).

Implementation

typedef AsyncError? ErrorCallbackHandler(Zone self, ZoneDelegate parent,
    Zone zone, Object error, StackTrace? stackTrace);