| // 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> lastWhere (bool test(T element), |
| /// {@deprecated dynamic defaultValue(), T orElse()}) |
| /// |
| /// Finds the last element in this stream matching test. |
| /// |
| /// If this stream emits an error, the returned future is completed with that |
| /// error, and processing stops. |
| /// |
| /// Otherwise as firstWhere, except that the last matching element is found |
| /// instead of the first. That means that a non-error result cannot be provided |
| /// before this stream is done. |
| /// |
| /// The defaultValue parameter is deprecated, and orElse should be used instead. |
| /// @description Checks that if this stream ends without finding a match and with |
| /// no [orElse] function provided, the future will receive an error. |
| /// @author kaigorodov |
| |
| library lastWhere_A04_t01; |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| void check<T>(Stream<T> s, bool test(T element)) { |
| AsyncExpect.error((e) => e is Error, s.lastWhere(test)); |
| } |
| |
| void test(CreateStreamFunction create) { |
| check(create([]), (element) => true); |
| check(create([1, 2, 3]), (int? element) => element == null); |
| check<int?>(create([null, null]), (int? element) => element != null); |
| check(create(new Iterable.generate(0, (int index) => index)), |
| (int element) => false); |
| check(create(new Iterable.generate(10, (int index) => index)), |
| (int element) => false); |
| check(create(new Iterable.generate(10, (int index) => index * 5)), |
| (int element) => element < 0); |
| check(create(new Iterable.generate(10, (int index) => index * 5)), |
| (int element) => element == 300); |
| } |