async/await recursive fs readdir

1.rreaddir.js

import { join } from 'path'
import { readdir, stat } from 'fs-promise'

async function rreaddir (dir, allFiles = []) {
  const files = (await readdir(dir)).map(f => join(dir, f))
  allFiles.push(...files)
  await Promise.all(files.map(async f => (
    (await stat(f)).isDirectory() && rreaddir(f, allFiles)
  )))
  return allFiles
}

2.rreaddirSync.js

// straight synchronous version for perf comparison
import { join } from 'path'
import fs from 'fs'

function rreaddirSync (dir, allFiles = []) {
  const files = fs.readdirSync(dir).map(f => join(dir, f))
  allFiles.push(...files)
  files.forEach(f => {
    fs.statSync(f).isDirectory() && rreaddirSync(f, allFiles)
  })
  return allFiles
}

3.bench.js

import assert from 'assert'

console.time('parallel')
rreaddir(__dirname).then(pFiles => {
  console.timeEnd('parallel')
  console.time('sync')
  const sFiles = rreaddirSync(__dirname)
  console.timeEnd('sync')
  assert.deepEqual(pFiles.sort(alpha), sFiles.sort(alpha))
})

function alpha (a, b) {
  return a.localeCompare(b)
}

4.bench.results.txt

parallel: 313.899ms
sync: 80.259ms