snapd, when installing a snap, has some logic to parse desktop files and generate a
mimeinfo.cache file that associates mime types to desktop files.
This allows e.g. a snapped app to advertise that it handles the
application/x-foobarbaz mime type.
However there doesn’t seem to be a way for the snap to register
application/x-foobarbaz as a new mime type (according to the shared-mime-info spec) so that it is recognized by the host system.
This would require invoking
update-mime-database on a directory containing xml descriptions.
Are there any plans to add this functionality to snapd?