Hi! I'm having a problem with this Kata, if I run it in js fiddle's console it works just fine, but here:

TypeError: Cannot read property 'includes' of undefined
at args.(anonymous function).args.(anonymous function).split.map.x
at Array.map

I'm using let titleCase = (...args) => {} to initialize the amount of parameters that the function is going to receive, but i'm not having good luck. Not sure how to check what words don't need to be UpperCased if there's no second input parameter giving this off.

I would appreciate some help.

Thanks