Rename a current route, and update all path helpers to the new name.

rename_route.rb

#! /usr/bin/env ruby
require 'pathname'

old_controller_name = ARGV[0]
new_controller_name = ARGV[1]

old_routes = `rake routes | grep #{old_controller_name}`.split("\n").map{|str| str.strip.split.first}.uniq.compact - ['GET','PUT','POST','DELETE','root']

routes_file_contents = File.read('config/routes.rb')
File.open('config/routes.rb', 'w'){|io| io.write routes_file_contents.gsub(":#{old_controller_name}", ":#{new_controller_name}") }

new_routes = `rake routes | grep #{new_controller_name}`.split("\n").map{|str| str.strip.split.first}.uniq.compact - ['GET','PUT','POST','DELETE','root']

modified_files = {}

Pathname.glob('app/**/*').each do |file|
  next unless file.extname =~ /rb\z/
  next if file.directory?

  puts file.to_s

  begin
    file_contents = file.read

    old_routes.each_with_index do |old_route, index|
      file_contents.gsub!(/(\W)#{old_route + '_path'}/, "\\1#{new_routes[index] + '_path'}")
      file_contents.gsub!(/(\W)#{old_route + '_url'}/, "\\1#{new_routes[index] + '_url'}")
      modified_files[file] = file_contents
    end
  rescue => ex
    puts [filename, ex.message, *ex.backtrace]
  end
end

modified_files.each{|file,contents| file.open('w'){|io| io.write contents}}