Obtaining the hash of a file using the stream capabilities of crypto module (ie: without hash.update and hash.digest)

Question

The crypto module of node.js (at the time of this writing at least) is not still deemed stable and so the API may change. In fact, the methods that everyone in the internet

Answer 1

An ES6 version returning a Promise for the hash digest:

function checksumFile(hashName, path) {
  return new Promise((resolve, reject) => {
    const hash = crypto.createHash(hashName);
    const stream = fs.createReadStream(path);
    stream.on('error', err => reject(err));
    stream.on('data', chunk => hash.update(chunk));
    stream.on('end', () => resolve(hash.digest('hex')));
  });
}