def test_delete():
linked_list = LinkedList()
abc = a, b, c = list('abc')
for i in abc:
linked_list.insert(i)
linked_list.delete(b)
assert linked_list.head.item is c
assert linked_list.head.next.item is a
assert linked_list.tail.item is a
linked_list.delete(a)
assert linked_list.head.item is c
assert linked_list.head.next.item is None
assert linked_list.tail.item is c
linked_list.delete(c)
assert linked_list.head.item is None
assert linked_list.tail.item is None
def test_delete_fail():
linked_list = LinkedList()
for i in 'abc':
linked_list.insert(i)
with pytest.raises(FileNotFoundError):
linked_list.delete('d')
