| // Copyright (c) 2020, 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:async_helper/async_minitest.dart'; |
| |
| const ms = const Duration(milliseconds: 1); |
| |
| /// Allows two asynchronous executions to synchronize. |
| /// |
| /// Calling [wait] and waiting for the returned future to complete will wait for |
| /// the other executions to call [wait] again. At that point, the waiting |
| /// execution is allowed to continue (the returned future completes), and the |
| /// more resent call to [wait] is now the waiting execution. |
| class Sync { |
| Completer _completer = null; |
| // Release whoever is currently waiting and start waiting yourself. |
| Future wait([v]) { |
| if (_completer != null) _completer.complete(v); |
| _completer = Completer(); |
| return _completer.future; |
| } |
| |
| // Release whoever is currently waiting. |
| void release([v]) { |
| if (_completer != null) { |
| _completer.complete(v); |
| _completer = null; |
| } |
| } |
| } |
| |
| expectList(stream, list) { |
| return stream.toList().then((v) { |
| expect(v, equals(list)); |
| }); |
| } |
| |
| mkStream(int n) async* { |
| for (int i = 0; i < n; i++) yield i; |
| } |