turkish-iban-validator/index.js

Türkiye IBAN numaralarını doğrulayan sade ve hızlı bir kütüphane.

function isValidTurkishIban(iban) {
  if (!iban || typeof iban !== 'string') return false;

  const formatted = iban.replace(/\s+/g, '').toUpperCase();
  if (!/^TR\d{24}$/.test(formatted)) return false;

  const rearranged = formatted.slice(4) + formatted.slice(0, 4);
  const numeric = rearranged.replace(/[A-Z]/g, ch => (ch.charCodeAt(0) - 55).toString());

  let remainder = '';
  for (let i = 0; i < numeric.length; i += 9) {
    remainder = (BigInt(remainder + numeric.slice(i, i + 9)) % 97n).toString();
  }

  return BigInt(remainder) === 1n;
}

function calculateCheckDigits(accountPart21Digit) {
  const temp = accountPart21Digit.toUpperCase();
  const ibanWithTR00 = `TR00${temp}`;
  const rearranged = ibanWithTR00.slice(4) + ibanWithTR00.slice(0, 4);
  const numeric = rearranged.replace(/[A-Z]/g, ch => (ch.charCodeAt(0) - 55).toString());
  const mod = BigInt(numeric) % 97n;
  return (98n - mod).toString().padStart(2, '0');
}

function generateTurkishIban(accountPart21Digit) {
  const checkDigits = calculateCheckDigits(accountPart21Digit);
  return `TR${checkDigits}${accountPart21Digit}`;
}

module.exports = {
  isValidTurkishIban,
  calculateCheckDigits,
  generateTurkishIban
};