from __future__ import annotations

import unittest
from datetime import datetime, timezone

from autofarm.sim.session_persistence import iso_timestamp


class SessionPersistenceTimestampTest(unittest.TestCase):
    def test_iso_timestamp_keeps_millisecond_precision(self) -> None:
        timestamp = iso_timestamp(datetime(2026, 4, 25, 12, 34, 56, 789123, tzinfo=timezone.utc))

        self.assertEqual(timestamp, "2026-04-25T12:34:56.789Z")


if __name__ == "__main__":
    unittest.main()