| // 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 |
| |
| /// @assertion factory StreamTransformer(StreamSubscription<T> |
| /// transformer(Stream<S> stream, bool cancelOnError)) |
| /// Creates a StreamTransformer. |
| /// |
| /// The transformer closure receives the stream, that was bound, as argument |
| /// and returns a StreamSubscription. In almost all cases the closure listens |
| /// itself to the stream that is given as argument. |
| /// |
| /// @description Checks that transformer receives a correct stream instance. |
| /// @author ilya |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| main() { |
| Stream<int> source = new Stream.fromIterable([1]); |
| StreamTransformer<int, dynamic> tr = new StreamTransformer( |
| (stream, cancelOnError) { |
| Expect.identical(source, stream); |
| asyncEnd(); |
| return stream.listen(null); |
| } |
| ); |
| |
| asyncStart(); |
| source.transform(tr).toList(); |
| } |