@skhemata/skhemata-form/src/validator/lib/isIMEI.js

Skhemata Form Web Component. This web component can be used as base web component when working with forms and inputs.

import assertString from './util/assertString';


let imeiRegexWithoutHypens = /^[0-9]{15}$/;
let imeiRegexWithHypens = /^\d{2}-\d{6}-\d{6}-\d{1}$/;


export default function isIMEI(str, options) {
  assertString(str);
  options = options || {};

  // default regex for checking imei is the one without hyphens

  let imeiRegex = imeiRegexWithoutHypens;

  if (options.allow_hyphens) {
    imeiRegex = imeiRegexWithHypens;
  }


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

  str = str.replace(/-/g, '');

  let sum = 0,
    mul = 2,
    l = 14;

  for (let i = 0; i < l; i++) {
    const digit = str.substring(l - i - 1, l - i);
    const tp = parseInt(digit, 10) * mul;
    if (tp >= 10) {
      sum += (tp % 10) + 1;
    } else {
      sum += tp;
    }
    if (mul === 1) {
      mul += 1;
    } else {
      mul -= 1;
    }
  }
  const chk = ((10 - (sum % 10)) % 10);
  if (chk !== parseInt(str.substring(14, 15), 10)) {
    return false;
  }
  return true;
}