Plastic

Luhn validation and card types for credit/debit card numbers

Here are some useful resources on the Luhn algorithm:

https://en.wikipedia.org/wiki/Luhn_algorithm
https://www.rosettacode.org/wiki/Luhn_test_of_credit_card_numbers

Thank you to Max Kramer for the initial inspiration.

Features

• Check the type of a card number (Amex, DinersClub, Discover, JCB, MasterCard or Visa)
• Check if a given card number is valid

Usage

let cardNumber = "3782 822463 10005"
let isValid = cardNumber.plastic_luhnValidate()
do {
    print(try cardNumber.plastic_cardType()) // Prints "Amex" in the console
} catch {
    // Handle error
    // Only error that Plastic throws is PlasticError.InvalidCardNumber
    // Thrown if the card number is < 9 digits and not Luhn valid
}

Tests

Test card numbers are from PayPal.