import pytest
from pydantic import ValidationError

from main import todoupdate


def test_todoupdate_rejects_empty_update() -> None:
    with pytest.raises(ValidationError):
        todoupdate()


def test_todoupdate_accepts_provided_value() -> None:
    update_data = todoupdate(
        task="学习测试单元",
        completion=True,
    )

    assert update_data.task == "学习测试单元"


def test_todoupdate_accepts_task_only() -> None:
    update_data = todoupdate(task="修改后的任务")

    assert update_data.task == "修改后的任务"
    assert update_data.completion is None