def test_get(self, doublelinkedlist):
node1 = DoubleLinkedNode(1)
node2 = DoubleLinkedNode(2)
node3 = DoubleLinkedNode(3)
doublelinkedlist.insert(node1)
doublelinkedlist.insert(node2)
doublelinkedlist.insert(node3)
assert doublelinkedlist.get(0) == node1
assert doublelinkedlist.get(1) == node2
assert doublelinkedlist.get(2) == node3
assert doublelinkedlist.get(1000) is None
def test_delete_head(self, doublelinkedlist):
node1 = DoubleLinkedNode(1)
node2 = DoubleLinkedNode(2)
node3 = DoubleLinkedNode(3)
doublelinkedlist.insert(node1)
doublelinkedlist.insert(node2)
doublelinkedlist.insert(node3)
assert doublelinkedlist.size == 3
doublelinkedlist.delete(node1)
assert doublelinkedlist.size == 2
assert doublelinkedlist.head.next == node3
assert doublelinkedlist.last.prev == node2
def test_pop(self, doublelinkedlist):
node1 = DoubleLinkedNode(1)
node2 = DoubleLinkedNode(2)
node3 = DoubleLinkedNode(3)
doublelinkedlist.insert(node1)
doublelinkedlist.insert(node2)
doublelinkedlist.insert(node3)
assert doublelinkedlist.pop() == node3
assert doublelinkedlist.size == 2
assert doublelinkedlist.pop() == node2
assert doublelinkedlist.size == 1
assert doublelinkedlist.pop() == node1
assert doublelinkedlist.size == 0
assert doublelinkedlist.pop() is None
def test_insert_bulk(self, doublelinkedlist):
nodelist = [DoubleLinkedNode(_) for _ in range(10)]
for node in nodelist:
doublelinkedlist.insert(node)
assert doublelinkedlist.size == 10
assert doublelinkedlist.last == nodelist[-1]
assert doublelinkedlist.head == nodelist[0]
assert doublelinkedlist.last.prev == nodelist[-2]
def test_prev(self):
node1 = DoubleLinkedNode(42)
node2 = DoubleLinkedNode(43)
node1.next = node2
node2.prev = node1
assert node1.next == node2
assert node2.prev == node1
assert node2.prev.value == 42
def node():
return DoubleLinkedNode()