def test_delete_head_of_list_with_one_item(self):
singlyLinkedListObject = SinglyLinkedList()
inputList = [1]
singlyLinkedListObject.populate(inputList)
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Now that the only element in the list is deleted, Head of empty list must be None")
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Now that the only element in the list is deleted, Head of empty list must be None")
def test_delete_head_of_empty_list_more_than_once(self):
singlyLinkedListObject = SinglyLinkedList()
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Head of empty list must be None")
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Head of empty list must be None")
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Head of empty list must be None")
def test_delete_head_of_list_with_more_than_one_item(self):
singlyLinkedListObject = SinglyLinkedList()
inputList = [1, 2, 3]
singlyLinkedListObject.populate(inputList)
singlyLinkedListObject.deleteHead()
self.assertFalse(singlyLinkedListObject.isHeadNone(), "Head of non-empty list must NOT be None")
self.assertFalse(singlyLinkedListObject.head == 2, "Expected hea data: %s, Actual head data: %s" %(2, singlyLinkedListObject.head))
singlyLinkedListObject.deleteHead()
self.assertFalse(singlyLinkedListObject.isHeadNone(), "Head of non-empty list must NOT be None")
self.assertFalse(singlyLinkedListObject.head == 3, "Expected hea data: %s, Actual head data: %s" %(3, singlyLinkedListObject.head))
singlyLinkedListObject.deleteHead()
self.assertTrue(singlyLinkedListObject.isHeadNone(), "Head of Empty list must be None")