| // 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 final Future<T> single |
| /// Returns the single element. |
| /// If this is empty or has more than one element throws a StateError. |
| /// @description Checks that a StateError is thrown if this is empty or has more than one element. |
| /// @author kaigorodov |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| import "IsolateStream.dart" as IsolateStream; |
| |
| void check(Stream s) { |
| asyncStart(); |
| s.single.then((value) { |
| Expect.fail("nonexpected: $value"); |
| }, onError: (error) { |
| Expect.isTrue(error is StateError); |
| asyncEnd(); |
| }); |
| } |
| |
| main() { |
| check(IsolateStream.fromIterable([])); |
| check(IsolateStream.fromIterable([1, 2])); |
| check(IsolateStream.fromIterable( |
| new Iterable.generate(0, (int index) => null))); |
| check(IsolateStream.fromIterable( |
| new Iterable.generate(2, (int index) => null))); |
| } |