using System.Collections.Generic;
using System.Linq;
using NUnit.Framework;

namespace Chernobyl.Utility
{
    class LinkedListExtensionsTests
    {
        [Test, Description("A test that ensures that LinkedListExtensions.GetNodes<T>(LinkedList<T>) " +
                           "returns all of the nodes in the proper order.")]
        public void GetThreeNodesTest()
        {
            var nodes = new LinkedList<int>();
            nodes.AddLast(0);
            nodes.AddLast(1);
            nodes.AddLast(2);

            using (IEnumerator<LinkedListNode<int>> nodeEnum = nodes.GetNodes().GetEnumerator())
            {
                nodeEnum.MoveNext();
                Assert.AreEqual(0, nodeEnum.Current.Value,
                                "The first node is not what was expected.");

                nodeEnum.MoveNext();
                Assert.AreEqual(1, nodeEnum.Current.Value,
                                "The second node is not what was expected.");

                nodeEnum.MoveNext();
                Assert.AreEqual(2, nodeEnum.Current.Value,
                                "The third node is not what was expected.");
            }
        }

        [Test, Description("A test that ensures that LinkedListExtensions.GetNodes<T>(LinkedList<T>) " +
                           "returns no nodes if there are non in the LinkedList<T>.")]
        public void GetNoNodesTest()
        {
            var nodes = new LinkedList<int>();
            Assert.False(nodes.GetNodes().Any(), "No nodes were expected in the " +
                         "LinkedList<T> but nodes were found.");
        }
    }
}