| // Copyright (c) 2015, 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 "dart:async"; |
| import "package:expect/expect.dart"; |
| import "package:async_helper/async_helper.dart"; |
| |
| Stream timedStream(int n) { |
| int i = 0; |
| StreamController controller; |
| tick() { |
| if (i >= n) { |
| controller.close(); |
| return; |
| } |
| controller.add(i); |
| i++; |
| new Future.delayed(new Duration(milliseconds: 0), tick); |
| } |
| |
| controller = new StreamController(onListen: tick); |
| return controller.stream; |
| } |
| |
| void main() { |
| asyncStart(); |
| StreamIterator iterator = new StreamIterator(timedStream(10)); |
| helper(more) { |
| if (!more) { |
| // Canceling the already closed iterator should not lead to a crash. |
| iterator.cancel(); |
| asyncEnd(); |
| } else { |
| iterator.moveNext().then(helper); |
| } |
| } |
| |
| iterator.moveNext().then(helper); |
| } |