import pytest

from article_data_manager.models import Article


def test_article_number_is_string_and_preserves_leading_zero() -> None:
    article = Article(nr="000123", name="Example")

    assert article.nr == "000123"


def test_article_number_rejects_numeric_value() -> None:
    with pytest.raises(TypeError):
        Article(nr=123)  # type: ignore[arg-type]