Teachable's Rubocop configuration, it's in a public repository so we can easily inherit from these settings.

By default, we enable all the cops and only disable the ones we don't like.

• Rubocop Documentation
• Configuration Options
• Enabled by default
• Disabled by default
• Rubocop Sourcecode

You inherit from the configurations you need and you can override settings in your own .rubocop.yml file.

Here's a common place to start for a Rails project:

require:
  - rubocop-performance
  - rubocop-rails
  - rubocop-rspec

inherit_from:
  - https://config.teachablecdn.com/rubocop/ruby.yml
  - https://config.teachablecdn.com/rubocop/performance.yml
  - https://config.teachablecdn.com/rubocop/rails.yml
  - https://config.teachablecdn.com/rubocop/rspec.yml

AllCops:
  EnabledByDefault: true
  ExtraDetails: true
  DisplayCopNames: true
  DisplayStyleGuide: true
  TargetRubyVersion: 2.6
  TargetRailsVersion: 5.2

And for non-rails projects:

require:
  - rubocop-performance
  - rubocop-rspec

inherit_from:
  - https://config.teachablecdn.com/rubocop/ruby.yml
  - https://config.teachablecdn.com/rubocop/performance.yml
  - https://config.teachablecdn.com/rubocop/rspec.yml

AllCops:
  EnabledByDefault: true
  ExtraDetails: true
  DisplayCopNames: true
  DisplayStyleGuide: true
  TargetRubyVersion: 2.6

The reason performance.yml is separate is because you need a separate gem for it. Add the rubocop-performance gem to your Gemfile to get it.

group :development, :test do
  gem "rubocop-performance", require: false
  gem "rubocop-rails",       require: false
  gem "rubocop-rspec",       require: false
end

We don't want to require it in normal use, just when running the rubocop command.

And it should go without saying that rubocop-rails should only be added when you are in a Rails project. The same goes for rubocop-rspec.

Also add this to your .gitignore file to not commit the cached configuration files.

.rubocop-*

To test the config, just run bundle exec rubocop.