import pytest
from solution import ListNode, Solution


def build(vals):
    head = None
    for v in reversed(vals):
        head = ListNode(v, head)
    return head


def to_list(node):
    out = []
    while node:
        out.append(node.val)
        node = node.next
    return out


@pytest.mark.parametrize(
    "l1,l2,expected",
    [
        ([2, 4, 3], [5, 6, 4], [7, 0, 8]),
        ([0], [0], [0]),
        ([9, 9, 9, 9, 9, 9, 9], [9, 9, 9, 9], [8, 9, 9, 9, 0, 0, 0, 1]),
    ],
)
def test_add_two_numbers(l1, l2, expected):
    result = Solution().addTwoNumbers(build(l1), build(l2))
    assert to_list(result) == expected