Credit Card detection regex

maskify.js

// Detect strings with potential credit cards in them and mask the credit cards.
// Credit card strings are strings that have 13-16 consecutive digits.

const maskify = (input) => {
	const regex = /\b\d{13,16}\b/;
  var card = input.match(regex);
  return (card) ? mask(input, card[0]) : input;
}

const mask = (input, card) => {
  const masked_card = card.slice(0, -4).replace(/./g, '*') + card.slice(-4);
	return input.replace(card, masked_card);
}

console.log(maskify('This is my credit card 12345678901 it has Eleven.'));
console.log(maskify('This is my credit card 123456789012 it has Twelve.'));
console.log(maskify('This is my credit card 1234567890123 it has Thirteen.'));
console.log(maskify('This is my credit card 12345678901234 it has Fourteen.'));
console.log(maskify('This is my credit card 123456789012345 it has Fifteen.'));
console.log(maskify('This is my credit card 1234567890123456 it has Sixteen.'));
console.log(maskify('This is my credit card 12345678901234567 it has Seventeen.'));
console.log(maskify('This is my credit card 123456789012345678 it has Eighteen.'));