module Grape
  module Validations
    class PresenceValidator < Validator
      def validate!(params)
        return unless @scope.should_validate?(params)
        super
      end

      def validate_param!(attr_name, params)
        unless params.respond_to?(:key?) && params.key?(attr_name)
          raise Grape::Exceptions::Validation, param: @scope.full_name(attr_name), message_key: :presence
        end
      end
    end
  end
end