@bitcoinerlab/secp256k1/test/util.js

A library for performing elliptic curve operations on the secp256k1 curve. It is designed to integrate into the BitcoinJS & BitcoinerLAB ecosystems and uses the audited noble-secp256k1 library. It is compatible with environments that do not support WASM,

import { Buffer } from "buffer";

export function fromHex(data) {
  return new Uint8Array(Buffer.from(data, "hex"));
}

export function toHex(data) {
  return Buffer.from(data).toString("hex");
}