rails/rails — pull request #8357 by garysweaver (2012-11-28 22:19:51+00:00)
Title: Adding ability to specify association class as :class vs. :class_name

To avoid having to type out class_name and a few quote characters for every non-standard class association, with these proposed changes can specify association with :class, e.g.:

belongs_to :employee, class: User

in addition to the old way:

belongs_to :employee, class_name: User