def test_at_raises_when_given_index_is_negative(
object_under_test: SinglyLinkedList,
):
object_under_test.insert_at_end(elem=18)
negative_index = -1
with pytest.raises(NegativeIndex) as exc:
object_under_test.at(idx=negative_index)
assert f"Given index: {negative_index} is negative" in str(exc.value)
def test_at_raises_when_given_index_bigger_than_size(
object_under_test: SinglyLinkedList,
):
object_under_test.insert_at_end(elem=18)
index_equal_to_size = 7
with pytest.raises(OutOfRangeIndex) as exc:
object_under_test.at(idx=index_equal_to_size)
assert (
f"Given index: {index_equal_to_size} is equal to or bigger than size: 1"
in str(exc.value)
)
def test_given_one_elem_then_at_zero_has_no_next(
object_under_test: SinglyLinkedList,
):
object_under_test.insert_at_end(elem=43)
node = object_under_test.at(idx=0)
assert node.next is None
def test_given_one_elem_then_at_zero_returns_that_elem(
object_under_test: SinglyLinkedList,
):
first_elem = 32
object_under_test.insert_at_end(elem=first_elem)
node = object_under_test.at(idx=0)
assert node.data == first_elem
def test_given_two_elements_then_at_one_returns_second_elem(
object_under_test: SinglyLinkedList,
):
second_elem = 311
object_under_test.insert_at_end(elem=78)
object_under_test.insert_at_end(elem=second_elem)
node = object_under_test.at(idx=1)
assert node.data == second_elem
def test_at_raises_when_list_is_empty(
object_under_test: SinglyLinkedList,
):
with pytest.raises(AtOnEmptyLinkedList):
object_under_test.at(idx=6)