Very good point, thanks! That is one of the little joys of CoffeeScript, many of the "defensive" coding practices don't exist. Fortunately, the book isn't just

Very good point, thanks! That is one of the little joys of CoffeeScript, many of the "defensive" coding practices don't exist. Fortunately, the book isn't just about avoiding problems but also about positive, productive idioms and practices. I think I picked this example in a bootless attempt to humblebrag by pointing out something I'd been cargo culting.