Node PoW

const crypto = require('crypto');
const fs = require('fs');

const hash = (block) => {
  const json = JSON.stringify(block);
  const hash = crypto.createHash('sha256');
  hash.update(json);
  return hash.digest('hex');
}

const block = {
  id: "some_id",
  data: "some_data",
  nonce: 0
};

while(true) {
  const block_hash = hash(block);
  console.log(block_hash);
  if(block_hash.startsWith('0')) {
    console.log("Proof of Work Found !")
    break;
  }
  block.nonce += 1;
}