Recently I’ve been aiming to do more katas, both in my personal time, and at work in our Deliberate Practice group.

I noticed that whenever I was starting on a new kata, I was doing the same basic setup repeatedly before being able to write a first test. I also felt I was missing some of the configuration that my other ‘real’ projects benefited from.

This led me to create ruby-kata-template. By clicking on Use this template, I get a new blank project in seconds, configured to my preferences.

I don’t expect my preferences to match everyone else’s, so I encourage you to fork it and customize to your own ideal template.


Starting Point

There is an empty Project (project.rb) and a corresponding test (project_test.rb). I expect the first step in many katas will be to rename these.

Directory Structure

I’ve followed the standard Ruby convention of the implementation being in lib/ and the tests in test/


Although Minitest is already provided as a Bundled gem with Ruby, it’s included in the Gemfile to ensure we’re on the latest version. (I’ve used RSpec extensively in the past, but my current preference is Minitest).


ActiveSupport::TestCase is part of Rails but here we are using it independently. It allows you to write ‘declarative’ tests, e.g. test "it works" do... rather than def test_it_works, which I feel is more readable.

Rake Task

It’s common on Ruby apps to have rake or rake test, so we provide that. It has support for both MiniTest naming conventions (test_*.rb and *_test.rb)


Standard is an opinionated RuboCop configuration.

For me, the real value of Standard (or RuboCop) is only apparent when you have two things configured in your editor:

  • Immediate feedback (your editor highlights problems as you code)
  • Auto-formatting (you can fix issues with one single shortcut, or automatically when the file is saved).

There are various ways to set up this, but the template uses rubocop-lsp.


rubocop-lsp is a gem which implements the Language Server Protocol. It allows for a close integration between your editor with RuboCop. It avoids the overhead of starting RuboCop, meaning linting or auto-correction is near-instant.

To use it, you’ll also need an plugin or extension for your editor. The template is set up to recommend the VS Code Shopify.rubocop-lsp extension.


Solargraph adds IDE-like experience for your editor. It provides helpful features such as a content-aware autocompletion, and documentation for the Ruby language.

However, I often run into problems with it, so I was on the fence about including it.

It’s not as powerful as Sorbet, so it’s unable to infer types unless they are a Ruby primitive (String, Array, etc.)

Solargraph example

And more

Take a look at the README to learn what else is included.