If a file extension is explicitly specified in the upload name, it is
always used directly. Detection of common file extension combinations is
also performed. Currently, only ".tar.gz" and ".tar.xz" are detected. If
you would like to add support for more common combinations, please open
an issue or pull request.
If no file extension is explicitly specified, jaf falls back to MIME
type detection via the github.com/gabriel-vasile/mimetype library.