public void RemoveFirst_WhenThereAreItems_ShouldResetTheHeadNode()
{
// Arrange
var linkedList = new SinglyLinkList<int>();
linkedList.AddFirst(new SinglyLinkListNode<int>(10));
linkedList.AddFirst(new SinglyLinkListNode<int>(20));
linkedList.AddFirst(new SinglyLinkListNode<int>(30));
// Act
linkedList.RemoveFirst();
// Assert
Assert.AreEqual(20, linkedList.GetHeadAndTail().Item1.Value, "Should return the expected head value.");
Assert.AreEqual(10, linkedList.GetHeadAndTail().Item2.Value, "Tail should have the expected value.");
Assert.AreEqual(2, linkedList.Count, "Number of items shall match.");
}
public void RemoveFirst_WhenThereAreOnlySingleItem_RemovingThisShouldSetListToEmpty()
{
// Arrange
var linkedList = new SinglyLinkList<int>();
// Act
linkedList.AddFirst(new SinglyLinkListNode<int>(10));
// Assert
Assert.AreEqual(1, linkedList.Count, "Should only contain 1 element.");
Assert.AreSame(linkedList.GetHeadAndTail().Item1, linkedList.GetHeadAndTail().Item2, "Head and tail should be pointing to same element.");
// Act
linkedList.RemoveFirst();
// Assert
Assert.AreEqual(0, linkedList.Count, "List should be empty.");
Assert.IsNull(linkedList.GetHeadAndTail().Item1, "Head should be empty.");
Assert.IsNull(linkedList.GetHeadAndTail().Item2, "Tail should be empty.");
}
public void RemoveFirst_WhenNoItemsInList_ListShouldRemainTheSame()
{
// Arrange
var linkedList = new SinglyLinkList<int>();
// Assert
Assert.AreEqual(0, linkedList.Count, "There shall be no items");
Assert.IsNull(linkedList.GetHeadAndTail().Item1, "Head should be null");
Assert.IsNull(linkedList.GetHeadAndTail().Item2, "Tail should be null");
// Act
linkedList.RemoveFirst();
// Assert
Assert.AreEqual(0, linkedList.Count, "There shall be no items.");
Assert.IsNull(linkedList.GetHeadAndTail().Item1, "Head should be null");
Assert.IsNull(linkedList.GetHeadAndTail().Item2, "Tail should be null");
}
