from agent.message_metadata import append_message, stamp_message_timestamp


def test_stamp_preserves_source_timestamp(monkeypatch):
    monkeypatch.setattr("agent.message_metadata.wall_time", lambda: 999.0)
    message = {"role": "user", "content": "hello", "timestamp": 123.0}

    result = stamp_message_timestamp(message)

    assert result is message
    assert message["timestamp"] == 123.0


def test_append_stamps_same_mapping_at_append_time(monkeypatch):
    monkeypatch.setattr("agent.message_metadata.wall_time", lambda: 456.0)
    messages = []
    message = {"role": "tool", "content": "ok"}

    result = append_message(messages, message)

    assert result is message
    assert messages == [message]
    assert message["timestamp"] == 456.0