xxhash implementation in pure typescript (using tc39 bigint), supports XXH64 & XXH3-128. These algorithms require Node.js >=12.x, because of Buffer::readBigUInt64LE

import { XXH64 } from 'xxh3-ts';
import { Buffer } from 'buffer';

let hash: bigint = XXH64(Buffer.from(JSON.stringify(v)))

For conversion back to buffer it's recommended to use bigint-buffer package or the following snippet:

function toBufferBE(num: bigint): Buffer {
  const hex = num.toString(16);
  // Padding *is* needed otherwise the last nibble will be dropped in an edge case
  return Buffer.from(hex.padStart(Math.ceil(hex.length/2) * 2, '0'), 'hex');
}

XXH64 was derived from the specifications at https://github.com/Cyan4973/xxHash/blob/v0.7.0/doc/xxhash_spec.md

XXH3-128 was ported from https://github.com/Cyan4973/xxHash/blob/v0.7.0/xxh3.h

As there is no specificatino for XXH3 in the specification documents.