errorZone property

The error zone is the one that is responsible for dealing with uncaught errors.

This is the closest parent zone of this zone that provides a handleUncaughtError method.

Asynchronous errors never cross zone boundaries between zones with different error handlers.

Example:

import 'dart:async';

main() {
var future;
runZoned(() {
// The asynchronous error is caught by the custom zone which prints
// 'asynchronous error'.
future = new Future.error("asynchronous error");
}, onError: (e) { print(e); });  // Creates a zone with an error handler.
// The following `catchError` handler is never invoked, because the
// custom zone created by the call to `runZoned` provides an
// error handler.
future.catchError((e) { throw "is never reached"; });
}

Note that errors cannot enter a child zone with a different error handler either:

import 'dart:async';

main() {
runZoned(() {
// The following asynchronous error is *not* caught by the `catchError`
// in the nested zone, since errors are not to cross zone boundaries
// with different error handlers.
// Instead the error is handled by the current error handler,
// printing "Caught by outer zone: asynchronous error".
var future = new Future.error("asynchronous error");
runZoned(() {
future.catchError((e) { throw "is never reached"; });
}, onError: (e) { throw "is never reached"; });
}, onError: (e) { print("Caught by outer zone: $e"); });
}