nodeUUIDv4.js

const uuid = () => { // Create a secure V4 UUID
    const randomHexChars = qty => crypto
        .randomBytes(Math.ceil(qty / 2))
        .toString('hex')
        .slice(0, qty);
    const reserved = ['8', '9', 'a', 'b'][crypto.randomBytes(1)[0] % 4];
    return [
        randomHexChars(8),
        randomHexChars(4),
        '4' + randomHexChars(3),
        reserved + randomHexChars(3),
        randomHexChars(12)
    ].join('-');
};