Whilst doing some work in a library I maintain, I needed to add in the ability to calculate the hash of an included file for an integrity check feature I was adding in. The resulting solution is simple and not really boast-worthy, but given others might encounter a situation where they need a hash of a file, this might help.

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

const fileBuffer = fs.readFileSync('myfile.js');
const hashSum = crypto.createHash('sha256');
hashSum.update(fileBuffer);

const hex = hashSum.digest('hex');

console.log(hex);

For the createHash method you can supply different supported algorithms including; md5, sha1 and sha256. To the digest method, you can supply hex or base64. If speed is important to you, sha1 and base64 are the two fastest options in most cases, however, all options are fairly fast anyway.