The Ruby
Linter/Formatter that
Serves and Protects

RuboCop is a Ruby static code checker (linter) and formatter based on the community-driven Ruby Style Guide

$ gem install rubocop

If you'd rather install using bundler, add a line for it in your Gemfile
(set the require option to false, as it is a standalone tool):

gem 'rubocop', require: false

Help fund the project

Find & autocorrect offenses

Check and automatically fix offenses on your Ruby code based on the Ruby Community Style Guide.

Learn more

Configure cops

Edit the .rubocop.yml configuration file to enable/disable certain cops (checks) and alter their behavior.

Learn more

Extend with plugins

Extend RuboCop with additional cops and formatters. There are many official and third-party extensions available.

Learn more

user_greeting.rb

 1# frozen_string_literal: true
 2
 3# Manages user greeting logic
 4class UserGreeting
 5  def sayHello(name)
 6    if name.nil?
 7      name = "stranger"
 8    end
 9
10    msg = "Hello, #{name}!"
11
12    if msg.length > 20
13      puts msg.upcase
14    end
15
16    return msg
17  end
18end
19

Plugins

.rubocop.yml

  1# It's possible to extend RuboCop with additional cops and formatters.
  2# Learn more
  3#
  4# Official Extensions maintained by the RuboCop's team:
  5# (clicking on them leads to their GitHub repo)
  6
  7---
  8plugins:
  9  - rubocop-performance  # Performance optimization analysis
 10  - rubocop-rails  # Rails-specific analysis
 11  - rubocop-rspec  # Rspec-specific analysis
 12  - rubocop-minitest  # Minitest-specific analysis
 13  - rubocop-rake  # Rake-specific analysis
 14  - rubocop-sequel  # Code style checking for Sequel gem
 15  - rubocop-thread_safety  # Thread-safety analysis
 16  - rubocop-capybara  # Capybara-specific analysis
 17  - rubocop-factory_bot  # factory_bot-specific analysis
 18  - rubocop-rspec_rails  # RSpec Rails-specific analysis
 19  - rubocop-i18n  # i18n wrapper function analysis (gettext and rails-i18n)
 20
 21# Third-party Extensions:
 22# https://docs.rubocop.org/rubocop/extensions.html#third-party-extensions
 23