FreeSurferSource doesn't check subjects_dir

[djarecka]

Summary

FreeSurferSource doesn't check subjects_dir is an existing path.

How to replicate the behavior

from nipype.interfaces.io import FreeSurferSource
fs = FreeSurferSource()
fs.inputs.subjects_dir = 'path/to/no/existing/directory'
fs.inputs.subject_id = 'sub-01'
res = fs.run()

Actual behavior

Doesn't give an error.

Expected behavior

Should check if directory exists (and possibly if there are files for subject_id ?).

[effigies]

Seems reasonable to add exists=True to subjects_dir, but I'd think enforcing a valid subject ID would be more trouble than it's worth.