process do |files|
  test_files = files.take_and_map do |file|
    if file =~ %r{^(spec|lib)/(.+?)(_spec)?\.rb$}
      path = $2
      if file =~ %r{^spec/spec_helper\.rb}
        ""
      else
        "spec/#{path}_spec.rb"
      end
    end
  end
  rspec_command = "time bundle exec rspec --tty --color"
  res = execute "#{rspec_command} #{test_files.join(' ')}" unless test_files.empty?
  if res.exit_code == 0 && test_files != [""]
    execute rspec_command
  end
end