JS Example of async counting of directories and files.

app.js

#!/usr/bin/env node

//
// Example of async counting of directories and files.
// 

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

let walk = function(fileOrDir, done) {
  
  let results = { dirCount: 0, fileCount: 0 };

  fs.readdir(fileOrDir, function(err, filelist) {
    if (err) return done(err);
    
    let pending = filelist.length;
    if (pending === 0) return done(null, results);
    
    filelist.forEach(function(file) {
      file = path.resolve(fileOrDir, file);
      
      fs.stat(file, function(err, stat) {
        if (stat && stat.isDirectory()) {
          console.log(`Walk: ${fileOrDir}`);
          results.dirCount++;
          walk(file, function(err, res) {
            results.dirCount += res.dirCount;
            results.fileCount += res.fileCount;
            if (--pending === 0) done(null, results);
          });
        } else {
          console.log(`file: ${file}`);
          results.fileCount++;
          if (--pending === 0) done(null, results);
        }
      }); // fs.stat
    }); // filelist.foreEach 
  }); // fs.readdir
};

walk('test', (err, results) => {
  if (err) 
    console.log('err ' + err);
  else
    console.log(`Dirs: ${results.dirCount}, files: ${results.fileCount}`);
});