The document discusses refactoring Ruby code to follow best practices like making code more readable, efficient, and flexible. It provides an example of refactoring a server restart/reload method to make the code more modular and ruby-like. The refactored code extracts a base daemon class that child classes like Nginx and Syslog inherit from. This allows calling methods like server.nginx.restart in a clearer way following ruby idioms.

1. Refactoring: The Ruby
Way
Shouichi KAMIYA

2. Goal
• Writing beautiful code in the ruby way

3. Beautiful
• Readable: easy to understand
• Efficient: easy to write
• Flexible: easy to extend

4. The Ruby Way
• Modular
• Method chaining
• English like

5. class Server < ActiveRecord::Base
def reload_nginx(flag = :reload)
if flag == :reload
ssh("user", address, "sudo /etc/init.d/nginx reload")
elsif flag == :restart
ssh("user", address, "sudo /etc/init.d/nginx restart")
end
end
def reload_syslog(flag = :reload)
# almost same as above
end
end

6. Problems
• Duplications
• if ... else ...
• The method named “reload” does “restart”

7. class Server < ActiveRecord::Base
def reload_nginx
exec("/etc/init.d/nginx”, “restart")
end
def restart_nginx
exec(“/etc/init.d/nginx”, “restart”)
end
def exec(path, arg)
ssh("user", address, "sudo #{path} #{arg}")
end
end

8. Still don’t feel right
• If it is a C, it might OK but, doesn’t look
very nice when it comes to ruby.

9. What we want
server = Server.find(id)
server.nginx.restart
server.nginx.reload

10. Modular
module Daemons
class Nginx
end
class Syslog
end
end

11. How to write
• User first: think of the users who use the
API you designed.

12. Ruby Idioms
module ActiveRecord
class User < AR::Base
class Base
has_many :articles
end
end
end

13. class Base
class << self
def has_path(path)
self.path = path
end
end
end
class Nginx < Base
has_path “/etc/init.d/nginx”
end
class Syslog < Base
has_path “/etc/init.d/syslog-ng”
end

14. class Base
def exec(*args)
ssh(“root”, address, “#{self.path} #{args}”)
end
def reload
exec(:reload)
end
def restart
exec(:restart)
end
end

15. Finally
class Server
def nginx
@nginx ||= Daemons::Nginx.new(self)
end
end
Server.find(id).nginx.restart

16. Thanks
• All source codes are available at https://
gist.github.com/749800