# frozen_string_literal: true class SedolValidator < BaseValidator REGEXP = /^([A-Z0-9]{6})(\d{1})$/.freeze WEIGHTS = [ 1, 3, 1, 7, 3, 9, 1 ].freeze private def valid_attr? valid_regexp? && valid_checksum? end def valid_checksum? total = 0 digits = value.chars.map { |dgt| /[A-Z]/.match?(dgt) ? (dgt.ord - 55) : dgt.to_i } digits.each_with_index { |dgt, idx| total += (WEIGHTS[idx] * dgt) } (10 - total % 10) % 10 end end