Rails: Good process for adding tests retroactively?

Question

I've got a few apps that I'd like to go back and retroactively build a test suite (RSpec & Cucumber) for, but it's a little daunting to get that process started.

What would your process be for going back on an existing app and building out a test suite for it?

Answer 1

I would go and add highlevel tests (cucumber) first. This will give you the confidence that the behavior won't change unnoticed. I wouldn't go and add rspec tests (or maybe just a few imporant ones) because you'll probably want to refactor a lot too.

Then, run metrics. MetricFu recently got a metric called "HotSpots", that will combine other metrics and point you to the biggest troublespots in the code. These places are usually also the most critical to your application. Fix them just enough so there readable and you get a good sense of what it's about. Don't go overboard just yet.

Then, for every new feature that you'll add, add specs and clean up some code that you're interacting with. So test and refactor the dependencies of new features, but don't go beyond that. Do it in tiny chunks or you'll lose hope quickly.