A [`crypto.getRandomValues` based,] "copy avoiding" UUID-4 generator for the Web

uuid.js

export const uuid4 = () => {
	const ho = (n, p) => n.toString(16).padStart(p, 0); /// Return the hexadecimal text representation of number `n`, padded with zeroes to be of length `p`
	crypto.getRandomValues(new Uint8Array(16)); /// Fill a data buffer with random data
	data[6] = (data[6] & 0xf) | 0x40; /// Patch the 6th byte to reflect a version 4 UUID
	data[8] = (data[8] & 0x3f) | 0x80; /// Patch the 8th byte to reflect a variant 1 UUID (version 4 UUIDs are)
	const view = new DataView(data.buffer); /// Create a view on the data buffer
	return `${ho(view.getUint32(0), 8)}-${ho(view.getUint16(4), 4)}-${ho(view.getUint16(6), 4)}-${ho(view.getUint16(8), 4)}-${ho(view.getUint32(10), 8)}${ho(view.getUint16(14), 4)}`; /// Compile the canonical representation of the data
};