// 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.

// @dart = 2.9

/// @assertion E elementAt(int index)
/// The [index] must be non-negative and less than [length]. Index zero
/// represents the first element (so [iterable.elementAt(0)] is equivalent to
/// [iterable.first]).
/// @description Checks that a RangeError is thrown if index is incorrect.
/// @author kaigorodov

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

DoubleLinkedQueue queue = new DoubleLinkedQueue();

void check(int index) {
  Expect.throws(() { queue.elementAt(index); }, (e) => e is RangeError);
}

main() {
  check(0);
  check (-10);

  queue.addFirst(1);
  check(1);
  check(2);
  check (-10);

  queue.addFirst(2);
  check(2);
  check(10);
  check (-10);

  queue.clear();
  check(0);
  check(1000);
  check (-10);
}