Watch a directory recursively

gistfile1.js

/**
 * Watch a directory recursively
 *  
 * @param {String} dir
 * @param {Function} cb
 * 
 *   watchRecursive('directory', function(current) {
 *     console.log(current, ' changed');
 *   });
 */

exports.watchRecursive = (function() {

  var fs = require('fs')
    , path = require('path');

  var lazycall = (function() {
    var start = 0
      , interval;
    return function(fn, interval) {
      interval = interval || 100;
      if (+new Date() - start >= interval) {
        fn && fn.call();
        start = +new Date();
      }
    };
  }());

  return function watch(dir, cb) {

    fs.watch(dir, function() {
      lazycall(function() {
        cb && cb.call(null, dir);
      })
    });

    fs.readdir(dir, function(err, all) {
      all.forEach(function(n) { 
        var file = path.join(dir, n);
        if (fs.statSync(file).isDirectory()) {
          watch(file, cb);
        };
      });
    });     

  };

}());