| // 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. |
| |
| // @dart = 2.9 |
| |
| library stream_controller_async_test; |
| |
| import 'dart:async'; |
| |
| import 'package:expect/expect.dart'; |
| import 'package:async_helper/async_helper.dart'; |
| |
| class A { |
| const A(); |
| } |
| |
| class B extends A { |
| const B(); |
| } |
| |
| class C extends B { |
| const C(); |
| } |
| |
| main() { |
| asyncStart(); |
| { |
| Stream<B> stream = new Stream<B>.fromIterable([new B()]); |
| A aFunc() => const A(); |
| // Make sure that lastWhere does not allow you to return instances |
| // of types that are not subtypes of the generic type of the stream. |
| stream.lastWhere((x) => false, //# badType: compile-time error |
| orElse: aFunc); // //# badType: continued |
| } |
| { |
| asyncStart(); |
| C cFunc() => const C(); |
| Stream<B> stream = new Stream<B>.fromIterable([new B()]); |
| // Make sure that lastWhere does allow you to return instances |
| // of types that are subtypes of the generic type of the stream. |
| stream.lastWhere((x) => false, orElse: cFunc).then((value) { |
| Expect.identical(const C(), value); |
| asyncEnd(); |
| }); |
| } |
| asyncEnd(); |
| } |