import pytest

from src.backend.utils import sql


@pytest.mark.parametrize("container_type", [list, tuple, set, frozenset])
@pytest.mark.parametrize(
    "param_count,expected",
    [
        (0, ""),
        (1, "%s"),
        (2, "%s,%s"),
        (3, "%s,%s,%s"),
    ],
)
def test_placeholders(container_type, param_count, expected):
    assert sql.placeholders(container_type(range(param_count))) == expected