| // 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 Stream<T> distinct([bool equals(T previous, T next)]) |
| /// Skips data events if they are equal to the previous data event. |
| /// The returned stream provides the same events as this stream, except that it |
| /// never provides two consecutive data events that are equal. |
| /// @description Checks that errors in original stream are copied to the returned |
| /// stream. [equals] is provided. |
| /// @issue #29627 |
| /// @author a.semenov@unipro.ru |
| |
| library distinct_A04_t02; |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| void check<T>(Stream<T> s, List<T> expectedData, List expectedErrors) { |
| AsyncExpect.events( |
| expectedData, expectedErrors, s.distinct((p, n) => p == n)); |
| } |
| |
| void test(CreateStreamWithErrorsFunction create) { |
| check(create([], defVal: 0), [], []); |
| check<int>(create([1, 2, 2, 3], isError: (e) => e.isEven, defVal: 42), [1, 3], [2, 2]); |
| check<int>( |
| create([1, 1, 2, 2, 3, 3], isError: (e) => e.isEven, defVal: 42), [1, 3], [2, 2]); |
| check<int>( |
| create([1, 1, 2, 2, 3, 3], isError: (e) => e.isOdd, defVal: 42), [2], [1, 1, 3, 3]); |
| check<int?>( |
| create([1, 2, null, null], isError: (e) => e is num, defVal: 42), [null], [1, 2]); |
| } |