credit-card-generator

generate fake nz credit cards for testing purposes

In order to smash through a million e2e tests a day, we need a pile of valid credit card numbers

This code will only generate Visa & Mastercard credit card numbers for ANZ & Kiwibank - not necessarily credit card numbers that exist, just valid numbers.

Adapted from this article... thanks friend! ᕕ( ᐛ )ᕗ

Expanding on this gist

... wait what

a checksum is the final digit in a credit card, and is calculated using the rest of the card number... this is what is used to validate a credit card number

Every second digit of the card number needs to be doubled... if the result is 10 or more, subtract 9 so that the result is only ever 1 digit long

then, add all those resulting numbers together - if that result is divisible by 10 with no remainder, it's a valid credit card... if it's not a valid credit card, you will get the remainder digit (ie 3)

to calculate the checksum, subtract the remainder from 10 ( 10 - 3 ) and you will get your checksum, 7

add this to the end of your invalid (partial) credit card number :D and wait for all your e2e tests to pass