How to extract JavaScript functions name of a project or file

Question

Having this kind of functions on a JavaScript project:

myfile.js

var foo = function () {
  return true;
}

var baa;
baa.too = function () {
  return true;
}

var taa = {
  tab: '',
  tac: function () { return true; }
}

function xoo () {
  return true;
}

Do you know if there is a way to get the names of the functions of all files included on a directory structure or just within a single file?

I'll expect something like this:

myfile.js   
 foo
    too
    taa.tac
    xoo

Maybe with some solution based on regex? Some command on console when the file is on browser memory? Or maybe with some feature/plugin of any editor (I'm using Atom.io) or an online tool?

Thank you! Art.