check rails project file extensions

checker.rb

#!/usr/bin/env ruby
extensions = %w[haml erb coffee scss]
check_regexps = %w[html.haml$ html.erb$ js.coffee$ css.scss$].map{|r|Regexp.new(r)}
files = Dir.glob("**/*")
files.each do |filename|
  extension = filename[/(?<=\.)[a-z]+$/]
  if extensions.include? extension
    extension_index = extensions.index extension
    check_regexp = check_regexps[extension_index]
    unless filename[check_regexp]
      puts filename
    end
  end
end