Alternative for no-peeping-toms on Rails4

spec_helper.rb

# add it to spec/spec_helper.rb
RSpec.configure do |config| 
  ...
  config.include TestObservers
  ...
end

test_observers.rb

# place file in spec/support
module TestObservers
  def with_observers(*observers)
    disabled_observers = ActiveRecord::Base.observers.send(:disabled_observers)
    ActiveRecord::Base.observers.enable(*observers)

    yield

    ActiveRecord::Base.observers.disable(*disabled_observers.to_a)
  end
end