RuboCop::CallbackChecker

A collection of RuboCop cops to ensure your ActiveRecord callbacks are safe, performant, and maintainable.

Banning callbacks entirely is a blunt instrument that slows down development. This gem provides a "surgical" approach—allowing callbacks for internal state management while preventing the most common architectural "gotchas" like recursive loops, phantom API calls, and bloated models.

Install the gem and add to the application's Gemfile by executing:

bundle add rubocop-callback_checker

If bundler is not being used to manage dependencies, install the gem by executing:

gem install rubocop-callback_checker

In your .rubocop.yml, add the following:

require:
  - rubocop-callback_checker

You can then run RuboCop as usual:

bundle exec rubocop

Goal: Prevent external side effects from running inside a database transaction.

If a side effect (like sending an email) triggers in an after_save but the transaction later rolls back, the email is sent for data that doesn't exist.

• Bad: Calling UserMailer.welcome.deliver_now in after_create.
• Good: Use after_commit or after_create_commit.

Goal: Prevent infinite recursion and "Stack Level Too Deep" errors.

• Bad: Calling self.save or update(status: 'active') inside a before_save.
• Good: Assign attributes directly: self.status = 'active'.

Goal: Reduce unnecessary database I/O.

Callbacks that run "before" persistence should only modify the object's memory state, not trigger a secondary database write.

• Bad: before_validation { update(attr: 'val') }
• Good: before_validation { self.attr = 'val' }

Goal: Prevent "Fat Models" and maintain testability.

Callbacks should be "post-it notes," not "instruction manuals." If a callback method is too long, it should be moved to a Service Object.

• Default Max: 10 lines.

Goal: Improve readability and allow for easier debugging.

• Bad: before_save :do_thing, if: -> { status == 'active' && !deleted? }
• Good: before_save :do_thing, if: :active_and_present?

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/rubocop-callback_checker.

The gem is available as open source under the terms of the MIT License.