bug: ITF-14 does not validate provided check digit

[productdevbook]

Summary

When a 14-digit ITF-14 code is provided (with check digit), src/encoders/itf.ts does not validate that the check digit is correct. It just passes the raw 14 digits through.

Details

export function encodeITF14(text: string): number[] {
  validateDigitsOnly(text);
  let digits: string;
  if (text.length === 13) {
    const nums = text.split("").map(Number);
    const check = calculateCheckDigit(nums);
    digits = text + String(check);
  } else if (text.length === 14) {
    digits = text;  // No validation!
  } else {
    throw new InvalidInputError("ITF-14 requires 13 or 14 digits");
  }
  return encodeITF(digits);
}

When 14 digits are provided, the check digit (last digit) should be verified against the calculated value, similar to how UPC-A does it.

Impact

ITF-14 barcodes with incorrect check digits are silently accepted. These barcodes will fail GS1 verification.

[productdevbook]

Fixed in commit a0867b3 / e4631a5 / b4e8107