| // Copyright (c) 2011, 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. |
| |
| /// @assertion Future<T> first |
| /// Stops listening to the stream after the first element has been received. |
| /// Internally the method cancels its subscription after the first element. |
| /// This means that single-subscription (non-broadcast) streams are closed and |
| /// cannot be reused after a call to this getter. |
| /// @description Checks that non broadcast stream can not be listened after |
| /// the first element is returned. |
| /// @author a.semenov@unipro.ru |
| |
| library first_A04_t01; |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| void check(Stream s) { |
| asyncStart(); |
| s.first.then( |
| (_) { |
| if (!s.isBroadcast){ |
| Expect.throws(() => s.listen((_){})); |
| } |
| asyncEnd(); |
| } |
| ); |
| } |
| |
| void test(CreateStreamFunction create) { |
| check(create([123])); |
| check(create([1,2,3])); |
| } |