attribute

# File activemodel/lib/active_model/attribute_registration.rb, line 12
      def attribute(name, type = nil, default: (no_default = true), **options)
        type = resolve_type_name(type, **options) if type.is_a?(Symbol)

        pending = pending_attribute(name)
        pending.type = type if type
        pending.default = default unless no_default

        reset_default_attributes
      end