changeValueForPath.js

var changeValueForPath = function (obj, path) {
  var key;
  path = path ? path + "." : "";

  for (key in obj) {
    if (Object.prototype.toString.call(obj[key]) === '[object Object]') {
      obj[key] = doTheThing(obj[key], path + key);
    } else {
      obj[key] = path + key
    }
  }

  return obj;
}