rubocop-kata

A RuboCop plugin that replaces a pile of linter gems and config with one dependency. Install it and your .rubocop.yml shrinks to project-specific overrides. Everything else comes from the gem: a curated stack of RuboCop extensions, opinionated style defaults, and four house cops.

• One dependency. Bundles rubocop-rspec, rubocop-performance, rubocop-elegant, rubocop-packaging, and rubocop-thread_safety behind a single gem.
• Opinionated defaults. Methods under 5 lines, classes under 100, 4 parameters max, 120-column lines, double quotes, NewCops: enable. See config/default.yml.
• Four house cops. Kata/AgentNoun, Kata/NoComments (autocorrecting), Kata/IoDiscipline, Kata/ProsePlacement.

class PaymentProcessor  # Kata/AgentNoun: `PaymentProcessor` names a doer;
end                     #   name the class for the thing it is, not the work it does.

class Payment           # OK
end

Getting started

Add the gem to your Gemfile:

gem "rubocop-kata", group: :development, require: false

Install it and point .rubocop.yml at the plugin:

plugins:
  - rubocop-kata

AllCops:
  TargetRubyVersion: 3.4

bundle install
bundle exec rubocop

That's it. The plugin loads the bundled extensions and the shared defaults, so your .rubocop.yml keeps only what's specific to your project. Requires Ruby >= 3.4 and RuboCop ~> 1.75.

The cops

Cop	Default	What it enforces
Kata/AgentNoun	on	Classes named for what they are, not -er/-or doers. Allow exceptions via AllowedNames.
Kata/NoComments	on	No prose comments; say it in the code. Magic comments, linter directives, and licence headers survive. Autocorrects.
Kata/IoDiscipline	on	No bare puts/warn/pp/p outside specs/scripts; write through an injected @io or an explicit receiver.
Kata/ProsePlacement	off	Sentence-length strings belong in the presentation layer. Enable with an Include/Exclude matching your layering.

The defaults

Double-quoted strings, Metrics/MethodLength: 5, Metrics/ClassLength: 100, Metrics/ParameterLists: 4, 120-column lines, endless methods on one line, rescue => error, NewCops: enable, and heredocs counted as one line in spec examples. See config/default.yml.

License

MIT.