RuboCop has had an “official” extensions for RSpec for years. In fact the rubocop-rspec project was the thing that pushed us in the direction to make RuboCop itself modular and to make it easy to create RuboCop extensions in general. There’s still a lot of work remaining to be done when it comes to providing a robust extension API, but the explosion of extensions in recent years certainly contributed to a lot of progress on that front. Today one of the important goals of the RuboCop project is to provide support for every important library or framework in the Ruby ecosystem, as they typically have their own sets of best practices. The big goal probably deserves its own post. Today, however, I just want to share with you a small milestone towards achieving it.

I’m a big fan of RSpec, but I also have a lot of appreciation and respect for the simple design of Minitest. Today I’m happy to announce that for a while we (RuboCop’s team) have been working on rubocop-minitest, which extends RuboCop with some extra understanding of Minitest. You can read a bit more about the project here.

Setting up rubocop-minitest is really simple. Just add it to your .rubocop.yml and you’re good to go:

require : - rubocop-other-extension - rubocop-minitest

By default all the cops are scoped to **/test/**/* , which in theory should work fairly well for most projects. Keep in mind, however, that you mind have to adjust it if your project utilizes some non-standard folder layout.

On a related note - we’ve also launched a Minitest Style Guide alongside the extension. Right now both the gem and the style guide are pretty basic, but I hope that with the help of the awesome Ruby community we’ll level them up quickly. Fortunately for us, the simplicity of Minitest means that there’s not that much work to do in general, at least compared to RSpec.