before_action with inheritance with opposite option

foo.rb

require "bundler/inline"

gemfile do
  source "https://rubygems.org"

  gem "rails"
  gem "pry-byebug"
end

require "rack/test"
require "action_controller/railtie"

class TestApp < Rails::Application
  config.root = __dir__
  config.hosts << "example.org"
  config.session_store :cookie_store, key: "cookie_store_key"
  secrets.secret_key_base = "secret_key_base"
  Rails.logger = Logger.new(STDOUT)

  routes.draw do
    get "/" => "test2#index"
  end
end

class TestController < ActionController::Base
  before_action :only_except, only: [:index]
  before_action :only_only, only: [:index]
  before_action :except_only, except: [:index]

  def index
  end

  def only_except
    @only_except ||= 0
    @only_except += 1
  end

  def only_only
    @only_only ||= 0
    @only_only += 1
  end

  def except_only
    @except_only ||= 0
    @except_only += 1
  end
end

class Test2Controller < TestController
  before_action :only_except, except: [:index]
  before_action :only_only, only: [:index]
  before_action :except_only, only: [:index]

  def index
    render(json: {only_except: @only_except, only_only: @only_only, except_only: @except_only})
  end
end

require "minitest/autorun"

class BugTest < Minitest::Test
  include Rack::Test::Methods

  def test_index
    get "/"
    assert_equal ({"only_except"=>nil, "only_only"=>1, "except_only"=>1}), JSON.parse(last_response.body)
  end

  private

  def app
    Rails.application
  end
end