    def test_sal_zeros(self, converter, thr_factor):
        """Test the SAL verification method."""
        precip, metadata = get_precipitation_fields(
            num_prev_files=0, log_transform=False, metadata=True
        )
        precip, metadata = converter(precip.filled(np.nan), metadata)
        result = sal(precip * 0, precip * 0, thr_factor)
        assert np.isnan(result).all()
        result = sal(precip * 0, precip, thr_factor)
        assert result[:2] == (-2, -2)
        assert np.isnan(result[2])
        result = sal(precip, precip * 0, thr_factor)
        assert result[:2] == (2, 2)
        assert np.isnan(result[2])
Test the SAL verification method.
pysteps/tests/test_verification_salscores.py