def test_retrieve_method(self):
linked_list = LinkedList()
find_me = {'foo4': 'bar', 'bar': 123}
self.assertFalse(linked_list.retrieve(find_me))
linked_list.insert(find_me)
self.assertEqual(find_me, linked_list.retrieve(find_me))
def test_add_and_retrieve(self):
ll = LinkedList()
ll.add('first')
assert ll.length() == 1
assert ll.retrieve(0) == 'first'
ll.add('second')
assert ll.length() == 2
assert ll.retrieve(0) == 'first'
assert ll.retrieve(1) == 'second'
ll.add('third')
assert ll.length() == 3
assert ll.retrieve(0) == 'first'
assert ll.retrieve(1) == 'second'
assert ll.retrieve(2) == 'third'
def test_remove(self):
ll = LinkedList()
ll.add('first')
ll.add('second')
ll.add('third')
ll.add('fourth')
assert ll.length() == 4
print ll
ll.remove(0)
assert ll.length() == 3
print ll.retrieve(0)
assert ll.retrieve(0) == 'second'
assert ll.retrieve(1) == 'third'
assert ll.retrieve(2) == 'fourth'
print ll
ll.remove(1)
assert ll.length() == 2
assert ll.retrieve(0) == 'second'
assert ll.retrieve(1) == 'fourth'
print ll
def test_create(self):
ll = LinkedList()
assert ll.length() == 0
assert ll.retrieve(0) == None
assert ll.remove(0) == None
