def test_wcsgroupcat_fit2ref(mock_fits_wcs, caplog, rect_imcat):
ra, dec = mock_fits_wcs.all_pix2world(rect_imcat.catalog['x'],
rect_imcat.catalog['y'], 0)
refcat = Table([ra, dec], names=('RA', 'DEC'))
ref = RefCatalog(refcat)
ref.calc_tanp_xy(rect_imcat.tpwcs)
g = WCSGroupCatalog(rect_imcat)
g.calc_tanp_xy(rect_imcat.tpwcs)
g.match2ref(ref)
g.fit2ref(ref, rect_imcat.tpwcs, fitgeom='shift')
g.apply_affine_to_wcs(g[0].tpwcs, np.identity(2), np.zeros(2))
g._images = []
g.align_to_ref(ref)
assert caplog.record_tuples[-1][-1].endswith("Nothing to align.")
def test_wcsgroupcat_update_bb_no_images(mock_fits_wcs, rect_imcat):
g = WCSGroupCatalog(rect_imcat)
g._images = []
g.update_bounding_polygon()
assert len(g.polygon) == 0