module ActiveModel
  module Validations
    class FalsityValidator < ActiveModel::EachValidator
      def validate_each(record, attribute, value)
        record.errors.add(attribute, :falsity,     :message => options[:message], :value => value) unless value.is_a?(FalseClass)
      end
    end

    module HelperMethods
      def validates_falsity_of(*attr_names)
        validates_with FalsityValidator, _merge_attributes(attr_names)
      end

      alias validates_falsehood_of validates_falsity_of
    end
  end
end