def test_remove(self):
"""Test removing of a node from a list."""
linked_list = DoublyLinkedList()
first_node = Node(1)
linked_list.insert_beginning(first_node)
node_to_remove = Node(2)
linked_list.insert_after(first_node, node_to_remove)
linked_list.insert_end(Node(3))
linked_list.remove(node_to_remove)
self.assertListItemsEqual(linked_list, [1, 3])
def test_insert_before(self):
"""Test insertion before a node."""
linked_list = DoublyLinkedList()
linked_list.insert_beginning(Node(1))
node = linked_list.first_node
for i in range(2, 4):
new_node = Node(i)
linked_list.insert_before(node, new_node)
node = new_node
self.assertListItemsEqual(linked_list, [3, 2, 1])
new_node = Node(10)
linked_list.insert_before(linked_list.last_node, new_node)
self.assertListItemsEqual(linked_list, [3, 2, 10, 1])
def test_insert_beginning(self):
"""Test insertion at the beginning of a list."""
linked_list = DoublyLinkedList()
first_node = Node(1)
linked_list.insert_beginning(first_node)
self.assertEqual(first_node, linked_list.first_node)
self.assertEqual(first_node, linked_list.last_node)
self.assertEqual(first_node.object, linked_list.first_node.object)
next_first_node = Node(2)
linked_list.insert_beginning(next_first_node)
self.assertEqual(next_first_node, linked_list.first_node)
self.assertEqual(first_node, linked_list.last_node)