Showcases a subtle problem that can occur due to getters.

broken.js

var optimist = require('optimist')
optimist.demand('color')
optimist.demand('size')
optimist.argv

works.js

var optimist = require('optimist')
optimist.demand('color')
optimist.demand('size').argv

plus .argv could easily just be .argv() here, I'm not bashing that API, I've used accessors plenty too, but IMO a language shouldn't even have them unless there's really a compelling reason, that's something I have yet to really see.

@rwldrn Agreed. However, it makes another thing that people need to keep in their minds if they copy something. Having a function (assuming it was bound to the correct object) that returned a value you could copy regularly. Not really arguing for or against, but this was something that made me do a double take when someone asked me about this situation.

Proxies will probably also have similar oddities that show up when people start making more use of them.

My thoughts are if you start using a language feature make sure you are aware of any nuances that might creep in.