Getting started

npm install @devix-labs/validators

import { validate } from '@devix-labs/validators';

const result = validate('iban', 'AE07 0331 2345 6789 0123 456');

Every answer has the same shape:

{
  valid: true,
  reason: 'valid',              // or 'too-short', 'bad-checksum', 'unknown-country'…
  kind: 'iban',
  value: 'AE070331234567890123456',        // cleaned: separators gone, upper-cased
  formatted: 'AE07 0331 2345 6789 0123 456',
  checked: 'checksum',          // or 'structure' — see below
  country: 'AE',
  details: { bankCode: '033', bban: '0331234567890123456', checkDigits: '07' },
}

checked is the important field#

A check digit can catch a typo. A number without one cannot be checked beyond its shape — and saying so is the difference between honest validation and a false sense of safety:

validate('emirates-id', '784199012345676').checked;   // 'checksum' — a typo is caught
validate('uae-trn', '100123456789012').checked;       // 'structure' — the FTA publishes no check digit

Never tell someone their TRN is "valid". Tell them it looks right.

What it knows#

VAT check digits are verified for AT, BE, DE, DK, FI, FR, GB, IE, IT, LU, NL, PL, PT, SE and SK.

Reason codes#

Turning a reason into a message#

const MESSAGES = {
  empty: 'Please enter your IBAN.',
  'too-short': 'That IBAN is too short — check you copied all of it.',
  'bad-checksum': 'That IBAN has a digit wrong. Check it against your bank statement.',
  'unknown-country': 'We can only take an IBAN from the UAE or Saudi Arabia.',
};

const result = validate('iban', input.value, { only: ['AE', 'SA'] });
if (!result.valid) show(MESSAGES[result.reason] ?? 'That does not look like an IBAN.');

One validator at a time#

Import only what you use — the package is side-effect free, so nothing else ships:

import { iban, emiratesId } from '@devix-labs/validators';

Formatting, masks and test data#

import { format, mask, generate } from '@devix-labs/validators';

format('iban', 'ae070331234567890123456');   // 'AE07 0331 2345 6789 0123 456'
format('cnic', '4210112345671');             // '42101-1234567-1'
mask('cnic');                                // '99999-9999999-9'  (9 digit, A letter, * either)
generate('emirates-id');                     // a valid Emirates ID that belongs to nobody
generate('iban', { country: 'SA', seed: 7 });// deterministic, for fixtures

generate() is for seeders, fixtures and demos. The numbers pass their own check digits and are not issued to anyone.

On the server#

devix-labs/laravel-validators is the same rules in PHP, with Laravel rules and messages:

composer require devix-labs/laravel-validators

$request->validate([
    'iban' => 'iban:AE,SA',
    'emirates_id' => 'emirates_id',
]);

224 shared vectors assert that both sides answer identically — including the reason code.