Bug: single_reference=True not working currently

[astrofrog]

I think a bug has been introduced with the recent release - reproject makes use of the single_reference=True option but this doesn't appear to be working anymore in the last few days:

https://github.com/astropy/reproject/actions/runs/6854228148/job/18815976303

Example error:

E               Exception: File not found for comparison test
E                                               Generated file:
E                                               	/var/folders/3s/vfzpb5r51gs6y328rmlgzm7c0000gn/T/tmp8ftf61xs/test_reproject_roundtrip[asdf].fits
E                                               This is expected for new tests.

but the reference file should be test_reproject_roundtrip.fits not test_reproject_roundtrip[asdf].fits

[astrofrog]

I wonder whether this is related to #36? (cc @ConorMacBride)

[ConorMacBride]

Yes, it's related to a bug in that PR. When the single reference option option is enabled it's generating the file name using item.name instead of item.function. Should be a quick fix. I'll try to get that in next week, unless someone gets there before me!

[pllim]

Like this? #43

Not sure how this repo handle milestone, so feel free to re-milestone and fix up the change log.