def test_values_exist_in_the_linked_list():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
assert linked_list.__str__() == "1 -> 2 -> 3 -> 4 -> None"
def test_add__node_to_the_end_of_the_linked_list():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
linked_list.append(5)
assert linked_list.__str__() == "1 -> 2 -> 3 -> 4 -> 5 -> None"
def test_insert_node_after_the_last_node():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
linked_list.insert_after(4, 5)
assert linked_list.__str__() == "1 -> 2 -> 3 -> 4 -> 5 -> None"
def test_insert_node_before_the_first_node():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
linked_list.insert_before(1, 5)
assert linked_list.__str__() == "5 -> 1 -> 2 -> 3 -> 4 -> None"
def test_insert_node_before_node_located_in_the_middle_of_linked_list():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
linked_list.insert_before(3, 5)
assert linked_list.__str__() == "1 -> 2 -> 5 -> 3 -> 4 -> None"
def test_k_is_not_postive_integer():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
actual = linked_list.kth(-3)
expected = "Input k is not a positive integer"
assert actual == expected
def test_k_same_length_as_list():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
actual = linked_list.kth(4)
expected = None
assert actual == expected
def test_kth_greater_than_the_length_of_the_linked_list():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
actual = linked_list.kth(10)
expected = "Input is greater than the length of the linked list"
assert actual == expected
def test_includes():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
linked_list = LinkedList()
linked_list.head = node1
node1.next = node2
node2.next = node3
node3.next = node4
assert linked_list.includes(1)
assert linked_list.includes(2)
assert linked_list.includes(3)
assert linked_list.includes(4)
assert linked_list.includes(5) == False
assert linked_list.includes(6) == False
def test_zip_lists_second_one_longer():
node1 = Node(1)
node2 = Node(2)
node3 = Node(3)
node4 = Node(4)
node1.next = node2
node2.next = node3
node3.next = node4
linked_list1 = LinkedList()
linked_list1.head = node3
linked_list2 = LinkedList()
linked_list2.head = node1
linked_list3 = LinkedList()
linked_list3 = linked_list3.zip_lists(linked_list1, linked_list2)
assert linked_list3.__str__() == "3 -> 1 -> 4 -> 2 -> 3 -> 4 -> None"
def test_llist_init_str_repr(llist):
first_node = Node(1)
second_node = Node('a')
assert str(llist) == 'None'
assert repr(llist) == 'LinkedList()'
llist._head = first_node
first_node.next = second_node
llist._tail = second_node
assert str(llist) == '1 -> a -> None'
assert repr(llist) == 'LinkedList(1, a)'
llist = LinkedList([2, 'b'])
assert str(llist) == '2 -> b -> None'
assert repr(llist) == 'LinkedList(2, b)'
