class Shoulda::Matchers::ActionController::RespondWithMatcher

def symbol_to_status_code(potential_symbol)
  case potential_symbol
  when :success  then 200
  when :redirect then 300..399
  when :missing  then 404
  when :error    then 500..599
  when Symbol
    if defined?(::Rack::Utils::SYMBOL_TO_STATUS_CODE)
      ::Rack::Utils::SYMBOL_TO_STATUS_CODE[potential_symbol]
    else
      ::ActionController::Base::SYMBOL_TO_STATUS_CODE[potential_symbol]
    end
  else
    potential_symbol
  end
end