Calculating SHA-1's of various strings to replicate how git calculates object filenames

git-object-filenames.js

// Calculating and printing the SHA-1 hash of strings

const crypto = require('crypto')
const zlib = require('zlib')

function hashIt(string) {
  return crypto
    .createHash('sha1')
    .update(string, 'utf-8')
    .digest('hex')
}

const string = 'hello\n'
const stringHexDigest = hashIt(string)

console.log(`raw: ${stringHexDigest}`)

const blob = `blob ${Buffer.byteLength(string)}\0${string}`
const blobHexDigest = hashIt(blob)

console.log(`blob: ${blobHexDigest}`)

const zipped = zlib.deflateSync(blob)
const zippedHexDigest = hashIt(zipped)

console.log(`zipped: ${zippedHexDigest}`)