Refactoring Sample

list.rb

module Hello
  class Account
    class List

      def initialize(request)
        @request = request
      end

      def list
        gather_wanted_strings
        gather_wanted_models

        gather_valid_strings
        ensure_consistency_accross_models_and_session
        
        return @models
      end

      private

      def gather_wanted_strings
        @wanted_strings = @request.session['access_tokens'] ||= []
      end

      def gather_wanted_models
        @models = find_models(@wanted_strings)
      end

          def find_models(access_tokens)
            case access_tokens.size
            when 0 then return @models = []
            when 1 then access_tokens = access_tokens.first
            end
            AccessToken.where(access_token: access_tokens)
          end

      def gather_valid_strings
        @valid_strings = @models.map(&:active_access_token_or_destroy).map(&:presence).compact
      end

      def ensure_consistency_accross_models_and_session
        if @wanted_strings != @valid_strings
          @request.session['access_tokens'] = @valid_strings
          @models = @models.select { |at| @valid_strings.include?(at.access_token) }
        end
      end
    end

  end
end