♯ How to compress jpeg images with sharp

.gitignore

/img/
/img-original/
/node_modules/
/package-lock.json
# Do not ignore package-lock.json other than gist

compress-images.mjs

import path from 'path'
import fsPromises from 'fs/promises'
import sharp from 'sharp'

export async function compressImages (srcdir, dstdir) {
  const dirents = await fsPromises.readdir(srcdir, {
    withFileTypes: true,
  })

  await fsPromises.mkdir(dstdir, {recursive: true})

  for (const dirent of dirents) {
    if (dirent.isDirectory()) {
      const srcdirJoin = path.join(srcdir, dirent.name)
      const dstdirJoin = path.join(dstdir, dirent.name)

      await compressImages(srcdirJoin, dstdirJoin)
    } else {
      const extname = path.extname(dirent.name)

      if (extname === '.jpg') {
        const src = path.join(srcdir, dirent.name)
        const dst = path.join(dstdir, dirent.name)
        const options = {mozjpet: true, quality: 80}

        await sharp(src).jpeg(options).toFile(dst)
      }
    }
  }
}

main.mjs

import path from 'path'
import {compressImages} from './compress-images.mjs'

main()

async function main () {
  try {
    const {pathname} = new URL(import.meta.url)
    const srcdir = path.join(pathname, '../img-original')
    const dstdir = path.join(pathname, '../img')

    await compressImages(srcdir, dstdir)
  } catch (err) {
    console.error(err)
  }
}

package.json

{
  "name": "compress-jpeg-image",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "postinstall": "mkdir -p img-original && cd img-original && curl -OJ 'https://images.pexels.com/photos/2662116/pexels-photo-2662116.jpeg?cs=srgb&dl=pexels-jaime-reimer-2662116.jpg&fm=jpg'",
    "start": "node main.mjs"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "sharp": "^0.30.7"
  }
}