Create uuid7()

uuid7.ts

function xuuid7(): string {
    const randomUUID = crypto.randomUUID();
    const randomUUIDArray = uuidToBytes(randomUUID);

    // Get the current timestamp in milliseconds
    const timestamp = Math.floor(Date.now());

    // Convert the timestamp to a byte array
    const timestampBytes = new Uint8Array(8);
    const timestampView = new DataView(timestampBytes.buffer);
    timestampView.setBigInt64(0, BigInt(timestamp));

    // Overlay the timestamp into the UUID
    for (let i = 0; i < 6; i++) {
        randomUUIDArray[i] = timestampBytes[i + 2];
    }

    // Set version 7 by flipping the 2nd and 1st bits in the 7th byte
    randomUUIDArray[6] = (randomUUIDArray[6] & 0x0f) | 0x70;

    // Set the variant to RFC 4122 (which is 10xx in binary)
    randomUUIDArray[8] = (randomUUIDArray[8] & 0x3f) | 0x80;

    return bytesToUUID(randomUUIDArray);
}

function uuidToBytes(uuid: string): Uint8Array {
    return Uint8Array.from(uuid.match(/[\da-f]{2}/gi)!.map((h) => parseInt(h, 16)));
}

function bytesToUUID(bytes: Uint8Array): string {
    const hex = Array.from(bytes, byte => byte.toString(16).padStart(2, '0')).join('');
    return `${hex.slice(0, 8)}-${hex.slice(8, 12)}-${hex.slice(12, 16)}-${hex.slice(16, 20)}-${hex.slice(20, 32)}`;
}

console.log(xuuid7());