Interview question of the issue #312 of rendezvous with cassidoo.
Implement the Luhn algorithm to validate a credit card number. Bonus points if you can identify what brand of credit card the user inputted!
Example:
> luhnCheck(123456789)
> false
> luhnCheck(5555555555554444)
> true // MastercardJust pnpm i to install all dependencies and then pnpm t to run the tests!