LibTest/collection/UnmodifiableListView/retainWhere_A01_t01.test.dart

// Copyright (c) 2017, 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 void retainWhere(bool test(E element))
/// This operation is not supported by an unmodifiable list.
/// @description Checks that [retainWhere] method is not supported.
/// @author iarkh@unipro.ru

import "dart:collection";
import "../../../Utils/expect.dart";

main() {
  UnmodifiableListView l = new UnmodifiableListView([1, 2, 3, 4, 5]);
  Expect.throws(() { l.retainWhere((var element) => true); },
      (e) => e is UnsupportedError);
  Expect.throws(() { l.retainWhere((var element) => element > 7); },
      (e) => e is UnsupportedError);
  Expect.throws(() { l.retainWhere((var element) => element = null); },
      (e) => e is UnsupportedError);
}