public void DeleteNodeTest()
{
Node <string> node1 = new Node <string>("abc");
BiDirectionalList <string> aList = new BiDirectionalList <string>(node1);
Assert.AreEqual(aList.Current, node1);
Assert.AreEqual(aList.Current, aList.Head);
Assert.AreEqual(aList.Current, aList.Last);
Assert.AreEqual(aList.Count, 1);
Node <string> node2 = aList.DeleteNode(node1);
Assert.AreEqual(node1, node2);
node2 = aList.AddNode(node1);
Assert.AreEqual(node1, node2);
node2 = aList.DeleteNode();
Assert.AreEqual(node1, node2);
node2.Value = "second-node";
aList.AddNode(node2.Value); // adding the value, not the node
node2 = aList.Current;
Assert.IsTrue(node1.Equals(node2));
Assert.AreEqual(node1, node2);
aList.InsertNode(node1);
aList.Current.Value = "first-node";
Assert.AreEqual(aList.Head, node1);
Assert.AreEqual(aList.Last, node2);
Assert.IsNull(aList.DeleteNode(""));
Node <string> node3 = aList.AddNode("3rd-node", node2.Value);
Assert.AreEqual(aList.Last, node3);
Assert.AreEqual(aList.Count, 3);
aList.SeekToHead();
Assert.AreEqual(aList.Current, aList.Head);
aList.SeekToLast();
Assert.AreEqual(aList.Current, aList.Last);
aList.SeekToNext();
Assert.IsNotNull(aList.Current);
aList.SeekToPrevious();
Assert.AreEqual(aList.Current.Value, node2.Value);
aList.SeekToPrevious();
Assert.AreEqual(aList.Current, node1);
aList.SeekToPrevious();
aList.SeekToNext();
Assert.AreEqual(aList.Current.Value, node2.Value);
aList.SeekToNext();
Assert.AreEqual(aList.Current, node3);
node2 = aList.DeleteNode(node2.Value);
Assert.AreEqual(aList.Current, node1);
aList.AddNode(node2.Value, 1);
Assert.AreEqual(aList.Current.Value, node2.Value);
aList.DeleteNode();
aList.InsertNode(node2.Value, 2);
Assert.AreEqual(aList.Current.Value, node2.Value);
aList.Clear();
Assert.AreEqual(aList.IsEmpty, true);
Assert.AreEqual(aList.Count, 0);
Assert.IsNull(aList.DeleteNode());
Assert.IsNull(aList.Current);
Assert.IsNull(aList.Head);
Assert.IsNull(aList.Last);
}
