First pretend you’re an Objective C professional and jump into iPhone development. (It helps to have absolutely no experience at this step.) Next, act over zealous about Test Driven Design and find the only unit testing framework that’ll half run against an iPhone project, one that just happens to be implemented in Ruby. Throw in a deadline just for fun You now have a recipe for achieve great feats in all things Ruby/Cocoa related and can now complain to your coworkers how stoopid Ruby is because it can only seem to intermittently find your method that is OBVIOUSLY defined on an objective C class you wrote moments ago.
Dumb Ruby programmers! How can anybody claim this technology is superior? Who cares that you didn’t read the documentation? Didn’t Joel say somewhere that users don’t read docs? Why can’t this stuff be easy enough to just pick up and use out of the box? After all if this were Java or Groovy you’d be finished by now!
Mumble a few more obscenities or discouraging words of condemnation toward the ultimately inferior platforms written by those who label themselves Rubyists or Cocoaists or whatever and then Google the thing you’re trying to do. What’s that towards the top of the page about how Ruby/Cocoa bridges work? Paraphrased:
The average idiot will note that RubyCocoa uses the Libffi library to call the Objective-C methods implementations. That means the first method call will go through the #method_missing mechanism, you moron, and then the Ruby method will be defined on the Ruby proxy class, thus allowing all (initial queries to Obj C classes to not know about the method while) further calls to be direct, and faster.
The best way to drive a developer nutz is to tell him something doesn’t exists when he/she is absolutely certain of the contrary. Go against logic. 1+1!=2, set a = b and (a == b) == false, function fooBar cannot be found because function fooBar is defined. There are plenty of other examples I’m sure.
Yes genius, you are attempting to learn Ruby Cocoa from the ass end. You know this but you are too arrogant to admit it, even to your significant other. Sure you’ll lie in bed and discuss things like how was work. The typical conversation leads you into a rambling session beginning with, “I had a bad day…” with you trying to explain to your incoherent loved one why things are getting you down. You can’t admit failure at this point as your loved one is lying, waiting for your to reveal weakness… any weakness that will serve as ammo in the next argument when you forget to cut the grass or have to run partially clad after the trash truck that powers away mercilessly from your residence because you had too many Bud Ice’s the prior night and passed out with that uncomfortable feeling that you knew you needed perform some important task but what the heck is it? No need to explain that you can’t perform your job because you skipped the fundamental steps required (actually learning the technology) to be productive in any capacity.
No worry, you can learn this stuff after you’ve used it. Learning is for sissies anyway, right? Who takes a class on starting an IV before declaring themselves a qualified Phd? That’s utter nonsense isn’t it? Just jam the damned needle somewhere close to the greenish looking line thing running down the arm and you’re all good! After the lawsuite begin you can enrol in Lincoln Tech and figure out why the deadly infection began in your first and only client. Yes we learn after we’ve trash talked the entire industry because it’s everyone else’s fault by now. The APIs should be written in a way that require no knowledge acquisition!
Disclaimer: The entirety of this article is meant tongue in cheek, while I appreciate all feedback positive and especially negative, don’t waste your time claiming Ruby and/or Cocoa is the best thing since Parish Smith got back with Eric Sermon. As a lover/consumer/advocate of anything programming related you’ll be preaching to the choir or buttering the tub of Land ‘o Lakes… you’ll be mowing the lawn mower… spray painting the brush, redundantly repeating the repetitive, repeatedly, or threading the thread spool. Save your keystrokes and don’t respond.
Can't see nothing but the source code 
There is an iPhone Unit Testing stack written in Objective C that you can use.
http://code.google.com/p/google-toolbox-for-mac/wiki/iPhoneUnitTesting.
Yeah, I’ve already picked it up and started using it. I’m now trying to get OCMock to play with it. I think I like using ObjC in my test code instead of having to pick up yet another language/platform. Still, I wanna get RSpec happening too so we’ll see.