LibTest/collection/DoubleLinkedQueue/removeFirst_A02_t01.dart

// 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 E removeFirst()
/// The queue must not be empty when this method is called.
/// @description Checks that exception is thrown if the queue is empty.
/// @author kaigorodov

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

check(List list) {
  DoubleLinkedQueue queue = new DoubleLinkedQueue.from(list);
  while(queue.length > 0) {
    Expect.equals(queue.removeFirst(), list[0]);
    Expect.equals(queue.length, list.length - 1);
    list.removeAt(0);
    int i = 0;
    queue.forEach((var element) {
      Expect.equals(list[i++], element);
    });
  }
}

main() {
  DoubleLinkedQueue queue = new DoubleLinkedQueue();
  
  Expect.throws(() { queue.removeFirst(); }, (e) => e is StateError);
  
  queue.addLast(1);
  queue.addLast(2);
  queue.clear();

  Expect.throws(() { queue.removeFirst(); }, (e) => e is StateError);
}