rails_code_loading.md

+-----------------------+------------------+-----------------+
|                       | eager load paths | auto load paths |
+-----------------------+------------------+-----------------+
| Rails 3 (development) | auto loaded      | auto loaded     |
| Rails 4 (development) | auto loaded      | auto loaded     |
| Rails 3 (production)  | eager loaded     | auto loaded     |
| Rails 4 (production)  | eager loaded     | eager loaded    |
+-----------------------+------------------+-----------------+

Same in Rails 3.2 and Rails 4

• Rails defaults:
  • eager_load: 'app/'
  • autoload: nothing
• Eager load paths get globbed via path/**/*.rb
• Autoload paths are roots from which Const.underscore should match dir structure