def test_is_k_longer_than_length():
ll = LinkedList()
ll.append_node(1)
ll.append_node(2)
ll.append_node(3)
with pytest.raises(IndexError):
ll.find_kth_value_from_end(4)
def test_negative_input():
ll = LinkedList()
ll.append_node(1)
ll.append_node(2)
ll.append_node(3)
# test will pass if code in block causes expected ERROR
with pytest.raises(ValueError):
ll.find_kth_value_from_end(-1)
def test_k_in_middle():
ll = LinkedList()
ll.append_node("a")
ll.append_node(3)
ll.append_node("3")
actual = ll.find_kth_value_from_end(1)
expected = 3
assert actual == expected
def test_is_k_same_as_length():
ll = LinkedList()
ll.append_node("a")
ll.append_node("b")
ll.append_node("c")
actual = ll.find_kth_value_from_end(2)
expected = "a"
assert actual == expected
def test_single_node_ll():
ll = LinkedList()
ll.insert("a")
actual = ll.find_kth_value_from_end(0)
expected = "a"
assert actual == expected
