Rails ActiveRecord and ActiveSupport callbacks wrapper for collecting metrics in pair with rspec

debug_callbacks.rb

if ENV["DEBUG_CALLBACKS"]
  Rails.application.eager_load!

  ActiveRecord::Callbacks::CALLBACKS.each do |callback_type|
    ApplicationRecord.descendants.each do |model|
      kind, name = callback_type.to_s.split("_")
      chain = model.__callbacks[name.to_sym]&.send(:chain)
      filtered = chain&.select { |chain_callback| chain_callback.kind == kind.to_sym }
      $callbacks_counter ||= {}
      $callbacks_counter[model.name] ||= {}
      $callbacks_counter[model.name][callback_type] = filtered&.count || 0
    end

    ApplicationRecord.define_method(:run_callbacks) do |kind, *args, &block|
      $callbacks_stack ||= []
      $callbacks_stack << [self.class.name, kind, caller_locations(1, 1).first.label].join("; ")
      super(kind, *args, &block)
    end
  end

  p $callbacks_counter

  RSpec.configure do |config|
    config.after(:each) do
      $callbacks_stack.each do |callback|
        puts callback
      end
      $callbacks_stack = []
    end
  end
end