discourse/lib/validators/regex_setting_validator.rb

# frozen_string_literal: true

class RegexSettingValidator
  LOREM =
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam eget sem non elit tincidunt rhoncus."

  def initialize(opts = {})
    @opts = opts
  end

  def valid_value?(val)
    !val.present? || valid_regex?(val)
  end

  # Check that string is a valid regex, and that it doesn't match most of the lorem string.
  def valid_regex?(val)
    r = Regexp.new(val)
    matches = r.match(LOREM)
    matches.nil? || matches[0].length < (LOREM.length - 10)
  rescue StandardError
    false
  end

  def error_message
    I18n.t("site_settings.errors.invalid_regex")
  end
end