30-seconds-of-code/test/lcm/lcm.js

module.exports = lcm = (...arr) => {
const gcd = (x, y) => (!y ? x : gcd(y, x % y));
const _lcm = (x, y) => x * y / gcd(x, y);
return [...arr].reduce((a, b) => _lcm(a, b));
};