Scans a directory in a recursive way using promises with async and await

recursiveScanAsync.js

const fs = require('fs');
const path = require('path');
const {
  promisify
} = require('util');
/**
Add Promise sugar to the fs.readdir and fs.stat functions
*/
const fsReadDir = promisify(fs.readdir);
const fsStat = promisify(fs.stat);

const recursiveScanAsync = async function (directory) {
  const files = await fsReadDir(directory);
  const promiseMap = files.map(async file => {
    const stat = await fsStat(path.join(directory, file));
    let localFiles = [];
    if (stat.isDirectory()) {
      localFiles = await recursiveScanAsync(path.join(directory, file));
    } else {
      localFiles.push(path.join(directory, file));
    }
    return localFiles;
  });
  /**
  * At this point promiseMap is a map of promises containing the recursive scan "promise" we need
  to solve all promises using Promise all with await
  */
  const finalRes = await Promise.all(promiseMap);
  /**
  Since generated result is an array of arrays we need to reduce each array
  flattening it into a final array using Array.prototype.reduce function
  */
  return finalRes.reduce((flat, toFlatten) => {
    return flat.concat(toFlatten);
  }, []);;
};

(async function () {
  const markDownFiles = await recursiveScanAsync('test')
  console.log(markDownFiles.filter(file => file.indexOf(".md") >= 0));
})();