own-keys 
Robustly get an object's own property keys (strings and symbols), including non-enumerables when possible.
Getting started
npm install --save own-keys
Usage/Examples
var ownKeys = require('own-keys');
var assert = require('assert');
assert.deepEqual(ownKeys({ a: 1, b: 2 }), ['a', 'b']);
assert.deepEqual(ownKeys([1, 2, 3]), [0, 1, 2, 'length']);
Tests
Simply clone the repo, npm install, and run npm test