Generate missing test files in a rails app

missing_tests.rake

namespace :missing_tests do
  def progress(name, x, y)
    print "\r #{name}: #{x}/#{y} %6.2f%%" % [x.to_f / y * 100]
  end

  def generate_files(name)
    kind       = name.to_s.singularize
    collection = Dir.glob Rails.root.join('app', name.to_s, '**', '*').to_s
    root       = Rails.root.join('app', name.to_s).to_s << '/'
    ext        = case name
                 when :controllers then '_controller.rb'
                 when :models      then '.rb'
                 when :jobs        then '_job.rb'
                 when :mailers     then '_mailer.rb'
                 end

    count = collection.count
    collection.each_with_index do |filename, index|

      `rails g test_unit:#{kind} #{Regexp.last_match(1)} -s` if filename.match(/#{root}(.+)#{ext}/)
      progress name, index, count
    end
  end

  task generate_tests: :environment do
    generate_files :controllers
    generate_files :models
    generate_files :jobs
    generate_files :mailers
  end
end

Usually I will create files in Rails using generators, but sometimes I forget. I use this script to add missing test files.