Install and use Rubocop - TLDR

Resources:

• https://docs.rubocop.org/rubocop-rails/index.html
• https://github.com/rubocop/rubocop-rails

Installation

Gemfile

group :development, :test do
  gem 'rubocop-rails', require: false
end

console

bundle
echo > .rubocop.yml

.rubocop.yml - basic setup example

require: 
  - rubocop-rails

AllCops:
  TargetRubyVersion: 3.0.1
  Exclude:
    - '**/db/schema.rb'
    - '**/db/**/*'
    - 'config/**/*'
    - 'bin/*'

Style/Documentation:
  Enabled: false

Style/ClassAndModuleChildren:
  Enabled: false

Rails/Output:
  Enabled: false

Style/EmptyMethod:
  Enabled: false

Bundler/OrderedGems:
  Enabled: false
  
Lint/UnusedMethodArgument:
  Enabled: false

Run the cops

console - run check:

bundle exec rubocop

console - run check on specific file/folder:

rubocop app/models/user.rb

Disable cops

1. in a file, for a method:

app/models/user.rb

  # rubocop: disable Metrics/AbcSize, Metrics/MethodLength
  def full_name
    ...
  end
  # rubocop: enable Metrics/AbcSize, Metrics/MethodLength

1. on a whole file:

.rubocop.yml

Metrics/ClassLength:
  Exclude:
    - 'app/models/user.rb'
    - 'app/controllers/users_controller.rb'

AutoCorrect

console - safe auto correct

rubocop -a

console - dangerous auto correct

rubocop - A

console - autocorrect a single specific cop

bundle exec rubocop -a --only Style/FrozenStringLiteralComment
bundle exec rubocop -A --only Layout/EmptyLineAfterMagicComment

generate comments for uncorrected problems and stop flagging them as TODO:

rubocop --auto-correct --disable-uncorrectable