def test_delete_empty_linked_list_raises_exception(self):
linked_list = LinkedList()
with self.assertRaises(Exception) as context:
linked_list.delete_node(1)
self.assertTrue("Linked List is empty!" in str(context.exception))
def test_delete_last_node_returns_deleted_node(self):
linked_list = LinkedList([1, 2, 3, 4])
deleted_node = linked_list.delete_node(4)
self.assertEqual(deleted_node.data, 4)
def test_delete_last_node_changes_reference(self):
linked_list = LinkedList([1, 2, 3, 4])
linked_list.delete_node(4)
expected = LinkedList([1, 2, 3])
self.assertEqual(expected, linked_list)
def test_delete_head_node_changes_reference(self):
linked_list = LinkedList([1, 2, 3, 4])
linked_list.delete_node(1)
expected = LinkedList([2, 3, 4])
self.assertEqual(linked_list, expected)