validator/lib/isISIN.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = isISIN;

var _assertString = _interopRequireDefault(require("./util/assertString"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var isin = /^[A-Z]{2}[0-9A-Z]{9}[0-9]$/;

function isISIN(str) {
  (0, _assertString.default)(str);

  if (!isin.test(str)) {
    return false;
  }

  var checksumStr = str.replace(/[A-Z]/g, function (character) {
    return parseInt(character, 36);
  });
  var sum = 0;
  var digit;
  var tmpNum;
  var shouldDouble = true;

  for (var i = checksumStr.length - 2; i >= 0; i--) {
    digit = checksumStr.substring(i, i + 1);
    tmpNum = parseInt(digit, 10);

    if (shouldDouble) {
      tmpNum *= 2;

      if (tmpNum >= 10) {
        sum += tmpNum + 1;
      } else {
        sum += tmpNum;
      }
    } else {
      sum += tmpNum;
    }

    shouldDouble = !shouldDouble;
  }

  return parseInt(str.substr(str.length - 1), 10) === (10000 - sum) % 10;
}

module.exports = exports.default;