class ActiveModel::Validations::LengthValidator

def check_validity!
  keys = CHECKS.keys & options.keys
  if keys.empty?
    raise ArgumentError, "Range unspecified. Specify the :in, :within, :maximum, :minimum, or :is option."
  end
  keys.each do |key|
    value = options[key]
    unless (value.is_a?(Integer) && value >= 0) || value == Float::INFINITY
      raise ArgumentError, ":#{key} must be a nonnegative Integer or Infinity"
    end
  end
end

def initialize(options)
  if range = (options.delete(:in) || options.delete(:within))
    raise ArgumentError, ":in and :within must be a Range" unless range.is_a?(Range)
    options[:minimum], options[:maximum] = range.min, range.max
  end
  if options[:allow_blank] == false && options[:minimum].nil? && options[:is].nil?
    options[:minimum] = 1
  end
  super
end

def skip_nil_check?(key)
  key == :maximum && options[:allow_nil].nil? && options[:allow_blank].nil?
end

def validate_each(record, attribute, value)
  value_length = value.respond_to?(:length) ? value.length : value.to_s.length
  errors_options = options.except(*RESERVED_OPTIONS)
  CHECKS.each do |key, validity_check|
    next unless check_value = options[key]
    if !value.nil? || skip_nil_check?(key)
      next if value_length.send(validity_check, check_value)
    end
    errors_options[:count] = check_value
    default_message = options[MESSAGES[key]]
    errors_options[:message] ||= default_message if default_message
    record.errors.add(attribute, MESSAGES[key], errors_options)
  end
end