| // Copyright (c) 2016, 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 Stream asyncExpand(Stream convert(T event)) |
| /// Creates a new stream with the events of a stream per original event. |
| /// |
| /// This acts like expand, except that convert returns a Stream instead of an |
| /// Iterable. The events of the returned stream becomes the events of the |
| /// returned stream, in the order they are produced. |
| /// |
| /// @description Checks that returned stream produces all the values generated by |
| /// the convert function. |
| /// @author a.semenov@unipro.ru |
| |
| library asyncExpand_A01_t01; |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| void check<T, E>( |
| Stream<T> stream, Stream<E> convert(T event), List<E> expected) { |
| AsyncExpect.data(expected, stream.asyncExpand(convert)); |
| } |
| |
| void test(CreateStreamFunction create) { |
| // expand to empty stream |
| check(create([]), (_) => create([]), []); |
| check(create([1, 2, 3, 4, 5]), (_) => create([]), []); |
| // expand to the same stream |
| check(create([]), (e) => create([e]), []); |
| check(create([1, 2, 3, 4, 5]), (e) => create([e]), [1, 2, 3, 4, 5]); |
| check(create(['a', null, 'b']), (e) => create([e]), ['a', null, 'b']); |
| // double events in the input stream |
| check(create([]), (e) => create([e, e]), []); |
| check(create([1, 2, 3]), (e) => create([e, e]), [1, 1, 2, 2, 3, 3]); |
| check(create(['a', null, 'b']), (e) => create([e, e]), |
| ['a', 'a', null, null, 'b', 'b']); |
| } |