isCcValidLuhn.js

/**
@func
calculate if credit card number is valid

@param {number|string} ccn Credit Card Number
@return {boolean}
*/
const isCcValidLuhn = ccn => {
  const sum = ccn
    .toString()
    .trim()
    .replace(/-/g, "") //removed dashes if exist
    .split("")
    .reverse()
    .map(s => parseInt(s))
    .map((n, index) => {
      if (index % 2 != 0) {
        n = n * 2 >= 10 ? n * 2 - 9 : n * 2;
      }
      return n;
    })
    .reduce((accu, curr) => accu + curr);
  return sum % 10 == 0;
}

//@tests
const ccNumsTrue = ["4012-8888-8888-1881", "5105-1051-0510-5100", "3714-496353-98431", "4012888888881881"];
const ccNumsFalse = ["1234-5678-9101-2131", "", "xyz"]; //throw on "" , , "xyz", 2e6
logForeachParam(isCcValidLuhn)(ccNumsTrue);
logForeachParam(isCcValidLuhn)(ccNumsFalse);
// logForeachParam sourcecode at: https://gist.github.com/funfunction/42918a4751ae51828cfc4c2dd4c0678e