Error commondata when running a closure test

Created by: RoyStegeman

While trying to run a closure test I got an error related to the line in commondata parser below. It removes the DATA_ prefix from commondata filenames, but instead, while running the closure test a commondata filename starting with FILTER_ was passed, so the prefix was not fully removed and as a result the name of the dataset is not recognised.

https://github.com/NNPDF/nnpdf/blob/f020b0bf2926fc85196441825896c8f955f1e69b/validphys2/src/validphys/commondataparser.py#L23

I also noticed these lines below. Does this mean DATA_ is the old format, and if I get a name with FILTER_ in the data parser above, the FILTER_ prefix should simply be removed or is there a more important difference between the two?

https://github.com/NNPDF/nnpdf/blob/f020b0bf2926fc85196441825896c8f955f1e69b/validphys2/src/validphys/loader.py#L238-L243

Maybe @siranipour knows more about this?