Test for spectra errors

[kelle]

def test_check_spectrum_wave_units_errors(t_spectrum):
    t_spectrum.spectral_axis = t_spectrum.spectral_axis * u.m  # Set incorrect units
    with pytest.raises(AstroDBError) as error_message:
        check_spectrum_units(t_spectrum, raise_error=True)         

    assert "Unable to convert spectral axis to microns" in str(error_message)


def test_check_spectrum_flux_units_errors(t_spectrum):