You can find them easily with these commands:
git grep "_(" koha-tmpl/intranet-tmpl/prog/js
git grep "_(" koha-tmpl/opac-tmpl/bootstrap/js
*** Bug 22601 has been marked as a duplicate of this bug. ***
I will create a xxx-strings.inc for each js
A Koha test must be provided here.
Won't be a problem with bug 21156.