iranian sheba bank validation javascript | اعتبار سنجی کد شبا با جاوا اسکریپت

sheba.js

function iso7064Mod97_10(iban) {
  var remainder = iban,
      block;

  while (remainder.length > 2){
    block = remainder.slice(0, 9);
    remainder = parseInt(block, 10) % 97 + remainder.slice(block.length);
  }

  return parseInt(remainder, 10) % 97;
}

function validateIranianSheba(str) {
  var pattern = /IR[0-9]{24}/;
  
  if (str.length !== 26) {
    return false;
  }

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

  var newStr = str.substr(4);
  var d1 = str.charCodeAt(0) - 65 + 10;
  var d2 = str.charCodeAt(1) - 65 + 10;
  newStr += d1.toString() + d2.toString() + str.substr(2, 2);
  
  var remainder = iso7064Mod97_10(newStr);
  if (remainder !== 1) {
    return false;
  }

  return true;
};

console.log(validateIranianSheba('ENTER SHEBA NUMBER HERE IT\'SRETURN TRUE OR FALSE'));

Great job
@hasanparasteh
The last statement in the validateIranianSheba function could also be simplified to:
return iso7064Mod97_10(testString) !== 1