// 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 final bool keys
/// @description Checks that [keys] return correct key list.
/// @author iarkh@unipro.ru

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

main() {
  UnmodifiableMapBase base = new UnmodifiableMapBaseImpl({});
  Iterable a = base.keys;
  Expect.isTrue(a.length == 0);

  base = new UnmodifiableMapBaseImpl({"1" : 1, "2" : 2});
  a = base.keys;
  Expect.isTrue(a.length == 2);
  Expect.isTrue(a.contains("1"));
  Expect.isTrue(a.contains("2"));
}