class TestLinkedList(unittest.TestCase):
linked_list = None
def setUp(self):
self.linked_list = LinkedList()
def test_init(self):
self.assertEqual(self.linked_list.head, None,
"Initial HEAD should be None")
self.assertEqual(len(self.linked_list), 0,
"Initial length should be zero")
def test_len(self):
self.assertEqual(len(self.linked_list), 0,
"Newly initiated list's length should be zero")
self.linked_list.insert(1)
self.assertEqual(len(self.linked_list), 1, "List length should be 1")
def test_list(self):
node1 = self.linked_list.Node(1, None)
node2 = self.linked_list.Node(2, node1)
node3 = self.linked_list.Node(3, node2)
self.linked_list.insert(1)
self.linked_list.insert(2)
self.linked_list.insert(3)
self.assertEqual([node3, node2, node1], list(self.linked_list))
def test_str(self):
self.linked_list.insert(1)
self.linked_list.insert(2)
self.linked_list.insert(3)
self.assertEqual(str(self.linked_list), '[3, 2, 1]',
"List should be printed as [3, 2, 1]")
self.linked_list.delete(2)
self.assertEqual(str(self.linked_list), '[3, 1]',
"List should be printed as [3, 1]")
self.linked_list.delete(3)
self.assertEqual(str(self.linked_list), '[1]',
"List should be printed as [1]")
self.linked_list.delete(1)
self.assertEqual(str(self.linked_list), '[]',
"List should be printed as []")
def test_insert(self):
self.assertEqual(
self.linked_list.insert(1), self.linked_list.Node(1, None),
"Inserting 1 into list should return node with value=1")
self.assertEqual(list(self.linked_list), [self.linked_list.Node(1)],
"Inserting 1 into empty list should give [1]")
self.linked_list.insert(3, 1)
self.assertEqual(self.linked_list.head.next,
self.linked_list.Node(3, None),
"Inserting 3 into pos=1 of [1] should give [1,3]")
self.linked_list.insert(2, 1)
self.assertEqual(
self.linked_list.head.next.value,
self.linked_list.Node(2, None).value,
"Inserting 2 into pos=1 of [1,3] should give [1,2,3]")
def test_contains(self):
self.linked_list.insert(1)
self.linked_list.insert(2)
self.linked_list.insert(3)
self.assertEqual(
1 in self.linked_list, True,
"After inserting 1 into the list, we should be able to find it there"
)
self.assertEqual(
4 in self.linked_list, False,
"After inserting 1 into the list, we should be able to find it there"
)
#print(self.linked_list)
def test_search(self):
self.linked_list.insert(1)
self.linked_list.insert(2)
self.linked_list.insert(3)
self.assertEqual(
self.linked_list.search(2).value,
self.linked_list.Node(2, None).value,
"Searching for 2 in [3,2,1] should return node with value=2")
self.assertEqual(self.linked_list.search(4), None,
"Searching for 4 in [3,2,1] should return None")
def test_delete(self):
self.linked_list.insert(1)
self.linked_list.insert(2)
self.linked_list.insert(3)
self.assertEqual(
self.linked_list.delete(2).value,
self.linked_list.Node(2, None).value,
"Deleting 2 from [3,2,1] should return the node with value 2")
self.linked_list.delete(3)
self.assertEqual(
self.linked_list.head, self.linked_list.Node(1, None),
"Deleting 2 and 3 from [3,2,1] should leave the list as [1]")
