Making A Code Coverage Tool for Ruby 1.9
You probably didn’t know this, but code coverage is actually a miracle. Who knows how it works? Oh wait, it’s exactly opposite of what I just said. It’s not a miracle, and we can learn how it works.
I’m not going to go in to depth, but this tool works by hooking in to Ruby's virtual machine...
It turns out that Ruby 1.9 already comes with support for code coverage monitoring. Aaron looks at how it works and improves how we interact with it a shade.