convert english numbers to persian with thousand seperator (without tolocalstring)

EnDigitsToPersian-without-toLocalString.js

function numberToPersian(number) {
  let numberToString = number.toString();
  let result = "";
  const farsiDigits = ["۰", "۱", "۲", "۳", "۴", "۵", "۶", "۷", "۸", "۹"];
  if (numberToString.length >= 4) {
    let toPersian = numberToString
      .split("")
      .map((x) => farsiDigits[x])
      .join("");

    let persianSplit = toPersian.split("");
    let firstPersianPart = persianSplit.length % 3;
    let noSecondPersianPart = Math.floor(persianSplit.length / 3);
    if (firstPersianPart != 0) {
      result = `${persianSplit.slice(0, firstPersianPart).join("")},`;
    }

    let secondPersianPart = persianSplit.slice(firstPersianPart);

    for (let i = 0; i < secondPersianPart.length; i = i + 3) {
      if (noSecondPersianPart <= 1) {
        result += `${secondPersianPart.slice(i).join("")}`;
        break;
      }
      result += `${secondPersianPart.slice(i, i + 3).join("")},`;
      noSecondPersianPart = noSecondPersianPart - 1;
    }
    return result;
  } else {
    result = numberToString
      .split("")
      .map((x) => farsiDigits[x])
      .join("");
    return result;
  }
}