replace.rb

class File
  def replace(pattern, string) 
    full_path = File.expand_path path
    return unless File.file?(full_path)

    reopen(full_path, 'r')
    lines = readlines

    changes = false
    lines.each_with_index do |line, index|
      if line.gsub!(pattern, string)
        changes = true
        $stdout << "#{full_path}:#{index} #{line}"
      end
    end

    if changes
      reopen(full_path, 'w')
      lines.each do |line|
        write(line)
      end
      close
    end
  end

  def replace_token(token, string)
    replace(/\b#{token}\b/, string)
  end
end


module Refactor
  class Base

    def self.paths(*args)
      @@paths = args
    end

    def self.replace(args={})
      @@subs = args
    end
    
    def execute
      if @@paths.nil?
        raise "No paths specified for refactor #{self.class}."
      end

      if @@subs.nil?
        raise "No replacements for refactor #{self.class}."
      end

      @@paths.each do |glob|
        Dir[glob].each do |filename|
          next if File.directory?(filename)
          file = File.open(filename)

          @@subs.each do |token, string|
            file.replace_token token, string
          end
        end
      end
    end
  end
end