setup-hs-mode.el

(add-to-list 'hs-special-modes-alist
	     '(ruby-mode
	       "\\(def\\|do\\|{\\)" "\\(end\\|end\\|}\\)" "#"
	       (lambda (arg) (ruby-end-of-block)) nil))

(add-hook 'ruby-mode-hook 'hs-minor-mode)