from fxhnt.ports.position_source import PositionSource


class _Stub:
    def current_weights(self, as_of: str) -> dict[str, float]:
        return {"USDTUSD": -1.0}


def test_protocol_structural():
    s: PositionSource = _Stub()
    assert s.current_weights("2026-06-21") == {"USDTUSD": -1.0}