This document discusses a Ruby module called TypoFixer that can detect and fix typos in method calls. It provides examples of how TypoFixer can find the correct method when a typo is made, such as calling "sme_motoehd" instead of "some_method". The module uses string permutations to find method names that are close to the one called with a typo. It also discusses enhancing TypoFixer to prompt the user before fixing the typo.

1. typo
2012-02-22
kchinda@aiming-inc.com
(a.k.a. @ckazu)

2. about me
• @ckazu
•
• G
• Rails
• Rails + JS
• Rails, Ruby 17

3. Shinjuku.rb #01

4. http://www.slideshare.net/ckazu/rails5

6. typo

7. typo

8. • typo

9. typo

10. •
• User.count → User.coutn

11. module TypoFixer
def self.included(base)
base.class_eval do
alias_method :method_missing_without_fix_typo, :method_missing
alias_method :method_missing, :method_missing_with_fix_typo
end
end
def method_missing_with_fix_typo(name, *args)
if name && method = find_method(name)
$stderr.puts "WARNING: execute `#{name}` as `#{method}` for #{self}"
send(method, *args)
else
method_missing_without_fix_typo(name, *args)
end
end
private
def find_method name
name.to_s.split(//).permutation.each do |candidate|
_candidate = candidate.join
return _candidate if respond_to?(_candidate, true)
end
nil
end
end
https://gist.github.com/1870273

12. require 'typo_fixer'
class Sample
include TypoFixer
def some_method
'some value'
end
end
sample = Sample.new
p sample.sme_motoehd #=> 'some value'
p sample.sme_motoehd.reveres #=> error!
https://gist.github.com/1870273

13. require 'typo_fixer'
class Object
include TypoFixer
end
p [1, 2, 3].shaflfe.joni #=> "213"
https://gist.github.com/1870273

14. •
• User.count → User.caunt

15. module TypoFixer
def self.included(base)
base.class_eval do
alias_method :method_missing_without_fix_typo, :method_missing
alias_method :method_missing, :method_missing_with_fix_typo
end
end
def method_missing_with_fix_typo(name, *args)
if method = find_method(name)
$stdout.print "WARNING: execute `#{name}` as `#{method}`? [Y/n] "
return send(method, *args) if ($stdin.getc == 'Y')
end
method_missing_without_fix_typo(name, *args)
end
private
def find_method name
self.class.instance_methods.each do |method|
next unless method.size == name.size
if(method.to_s.split(//) - name.to_s.split(//)).size == 1
return method
end
end
end
end https://gist.github.com/1883331

16. require 'typo_fixer'
class Object
include TypoFixer
end
p "some string".revarse #=> "gnirts emos"
https://gist.github.com/1870273

17. •
• array.flatten → array.flaten

18. •

19. •
• car.control → car.controll

20. •

21. •
• User.fin_dvy_id(di)

22. •

23. • method typo

26. •

33. http://suburi.herokuapp.com/