In this episode, Joe and Ben look at a class which was written without using TDD. By rewriting it with tests first, we discover that a new class was waiting to be extracted, making the overall solution clearer.
This is a companion discussion topic for the original entry at https://thoughtbot.com/upcase/videos/demonstrate-class-design-via-tdd
What VIM plugin are you using to get the terminal in another pane?
You can also use windows in vim with ctrl +w {v,s}
Apparently thoughtbot thinks this guy is awesome too, but this is some info on windows