Currently we have abstract layout test classes in Symfony\Component\Form\Tests namespace. None of these classes is extended in the Symfony\Component\Form namespace. All tests are implemented in Symfony\Bridge\Twig namespace.

At the same time the templates for which these abstract tests are designed also live in TwigBridge.

Because of this after any change in templates we have to adjust requirements in symfony/twig-bridge for deps=high and deps=low to pass.

I suggest moving abstract tests to TwigBridge. As far as I know, tests are considered internal, so this won't be a BC break.