Recursive search for files by filename in nested directories

_ Recursive search for files by filename in nested directories

Let's write a class that looks for file in nested directories.

We need 2 files:

1) Module file: `FileSearch.js`
2) Usage (example) code that use that `FileSearch` module.

p.s. module and usage (example) code are written in ES6 standart.

FileSearch.js

const
  fs = require('fs'),
  path = require('path'),
  EventEmitter = require('events');

class FileSearch extends EventEmitter  {
  
  constructor(filename, startDir) {
    super();
    this._filename = filename;
    this._dir = startDir;
  }
  
  _find(dir) {
    let self = this;
    fs.readdir(dir, (err, entries) => {
      for(let entry of entries) {
        fs.stat(
          path.join(dir, entry), 
          self._onStat(path.join(dir, entry))
        );
      }
    });
  }

  _onStat(entry) {
    let self = this;
    return (err, stat) => {
      if(!stat) return;
      if(stat.isDirectory()) return self._find(entry);
      if(stat.isFile() && path.basename(entry) == self._filename) {
        self.emit('match', entry);
      }
    }
  }

  run() {
    this._find(this._dir);
  }
}

module.exports = FileSearch;

usage.js

const 
  FileSearch = require('./FileSearch.js');

// let's look for 'index.js' files in '~/Projects' (ex.: /Users/num8er/Projects)
let fileSearch = new FileSearch('index.js', '~/Projects'); 
fileSearch.on('match', (file) => {
  console.log('Found file:', file);
});
fileSearch.run();