applyFallthroughAttributes doesn't apply when a <?php preamble is present

[iamdadmin]

Tempest version

3.3.1 dev-main

PHP version

8.5

Operating system

Linux, macOS

Description

applyFallthroughAttributes uses /^<(?<tag>[\w-]+)/ without the m (multiline) flag which anchors to the absolute start of the viewComponent.

For x-form-view.php, x-input-view.php, x-submitview.phpand any of the other built-ins or self-created components with a<?php` preamble the regex never matches, and fallthrough attributes silently don't apply.

I've extended the Fixtures and test to demonstrate this (attached for info)

fallthrough-preamble.view.php
x-fallthrough-preamble-dynamic-test.view.php
x-fallthrough-preamble-test.view.php

FallthroughAttributesTest.php

[iamdadmin]

I would however argue, that we actually should remove applyFallthroughAttributes and have them remain as variables which are used, or not, by the developer, in-line with closure semantics from Brent's comments in #2026 due to collision and lack of ability to turn it on or off on a case-by-case basis. In the case that developers and this applies to me too, where all my .view.php have a <?php block to at least docblock props, it would be breaking behaviour to fix it, so removing it may be less breaking, depending.

Consider if someone is using a Class Variance utility like my own tweaked https://github.com/iamdadmin/vewe-classvariance or any of the other implementations, the developer needs to be able to pass $class into that for collision treatment, whereas if class is automatically fallthrough, it will be merged inline and won't get collision treatment.