Raise custom exception on request error

sketch.rb

class ApprovalError < StandardError
  def initialize(response)
    @response = response
    @request = response.request
  end

  def inspect
    "uri: #{@request.uri}, response_body: #{@response.body}"
  end
end

class ApprovalBadGatewayError < ApprovalError; end
class ApprovalInternalServerError < ApprovalError; end

module Fontana
  module Approval
    class Workflow

      def update
        result = self.class.put(
          "#{approvals_api_uri}/#{id}",
          :headers => approval_request_headers,
          :body => to_json
        )
        handle_approval_error(response) unless result.success?

        # ...

        def handle_approval_error(response)
          case response.code
            when '502'
              raise ApprovalBadGatewayError.new(response)
            when '500'
              raise ApprovalInternalServerError.new(reponse)
            else
              raise ApprovalError.new(reponse)
          end
        end
      end

    end
  end
end