class ActiveModel::Validations::LengthValidator

def check_validity!
  keys = CHECKS.keys & options.keys
  if keys.empty?
    raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
  end
  keys.each do |key|
    value = options[key]
    unless value.is_a?(Integer) && value >= 0
      raise ArgumentError, ":#{key} must be a nonnegative Integer"
    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.begin, range.end
    options[:maximum] -= 1 if range.exclude_end?
  end
  super(options.reverse_merge(:tokenizer => DEFAULT_TOKENIZER))
end

def validate_each(record, attribute, value)
  value = options[:tokenizer].call(value) if value.kind_of?(String)
  CHECKS.each do |key, validity_check|
    next unless check_value = options[key]
    value ||= [] if key == :maximum
    value_length = value.respond_to?(:length) ? value.length : value.to_s.length
    next if value_length.send(validity_check, check_value)
    errors_options = options.except(*RESERVED_OPTIONS)
    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