| // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| // @dart = 2.9 |
| |
| import 'package:expect/expect.dart'; |
| import 'package:async_helper/async_helper.dart'; |
| import 'dart:async'; |
| |
| main() { |
| Completer done = new Completer(); |
| |
| var valueToCapture; |
| var restoredValue; |
| |
| Expect.identical(Zone.root, Zone.current); |
| Zone forked = Zone.current.fork(specification: new ZoneSpecification( |
| registerUnaryCallback: |
| <R, T>(Zone self, ZoneDelegate parent, Zone origin, R f(T arg)) { |
| // The zone is still the same as when origin.run was invoked, which |
| // is the root zone. (The origin zone hasn't been set yet). |
| Expect.identical(Zone.current, Zone.root); |
| // Note that not forwarding is completely legal, though not encouraged. |
| var capturedValue = valueToCapture; |
| return parent.registerUnaryCallback(origin, (arg) { |
| restoredValue = capturedValue; |
| return f(arg); |
| }); |
| })); |
| |
| valueToCapture = 499; |
| var fun = (x) => x + 99; |
| var registered = forked.registerUnaryCallback(fun); |
| Expect.isFalse(identical(fun, registered)); |
| |
| // It is valid to invoke the callback in a different zone. This is, of course, |
| // extremely discouraged. |
| var result = registered(399); |
| Expect.equals(498, result); |
| Expect.equals(499, restoredValue); |
| } |