thoughtbot--shoulda-matchers/lib/shoulda/action_controller/respond_with_matcher.rb

module Shoulda # :nodoc:
  module ActionController # :nodoc:

    # Ensures a controller responded with expected 'response' status code.
    #
    # You can pass an explicit status number like 200, 301, 404, 500
    # or its symbolic equivalent :success, :redirect, :missing, :error.
    # See ActionController::StatusCodes for a full list.
    #
    # Example:
    #
    #   it { should respond_with(:success)  }
    #   it { should respond_with(:redirect) }
    #   it { should respond_with(:missing)  }
    #   it { should respond_with(:error)    }
    #   it { should respond_with(501)       }
    def respond_with(status)
      RespondWithMatcher.new(status)
    end

    class RespondWithMatcher # :nodoc:

      def initialize(status)
        @status = symbol_to_status_code(status)
      end

      def matches?(controller)
        @controller = controller
        correct_status_code? || correct_status_code_range?
      end

      def failure_message
        "Expected #{expectation}"
      end

      def negative_failure_message
        "Did not expect #{expectation}"
      end

      def description
        "respond with #{@status}"
      end

      protected

      def correct_status_code?
        response_code == @status
      end

      def correct_status_code_range?
        @status.is_a?(Range) &&
          @status.include?(response_code)
      end

      def response_code
        @controller.response.response_code
      end

      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

      def expectation
        "response to be a #{@status}, but was #{response_code}"
      end

    end

  end
end