1) somecoolclass.rb
2) some_cool_class.rb
3) some-cool-class.rb
4) SomeCoolClass.rb
or some other variation?
I noticed in the Ruby stdlib, versions 1, 2 and 3 are used.
I'm not sure about the Ruby convention here, but I know Ruby on Rails
uses #2 (some_cool_class.rb).
In Rails, this convention is necessary for some of the magic: if you
reference MyConstant::MyClass and it's not known, Rails uses
const_missing to translate that to my_constant/my_class and tries to
find that in the load path.