fix potential fatal error on Interactivity API processing directives …

[hugosolar]

This may be an edge case for posts created with Classic editor or classic editor block.
_process_directives function within WP_Interactivity_API class will process html and check for closer tags.
if there's a wrong tag like </br> (in my case) will result in a TypeError:

Fatal error: Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in wp-includes/interactivity-api/class-wp-interactivity-api.php on line 442

by checking the line of code, count() function is applied to get_attribute_names_with_prefix() method from WP_HTML_Tag_Processor which can eventually return null

for newer PHP version (8.0.0 and later) this will throw a fatal error.
probably worth getting an extra check if the funcion is returning a countable variable

Trac ticket: https://core.trac.wordpress.org/ticket/63891

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[sirreal]

Thanks @hugosolar! Did you consider adding a unit test that covers this?

This change seems good to me but I'd like @luisherranz and/or @DAreRodz to review.

[sirreal]

I'd prefer a null check here, it's more consistent with other HTML API code:

Suggested change

	if ( ! is_countable( $each_child_attrs ) ) {
	if ( null === $each_child_attrs ) {

[DAreRodz]

Nice catch, @hugosolar. 🙂

I left a comment. I would be great if you could add a unit test for this case, as @sirreal mentioned. Unit tests for the Interactivity API are inside the tests/phpunit/tests/interactivity-api folder.

[DAreRodz]

I'm not 100% sure right now, but I think the else block below should execute when $each_child_attrs is null, shouldn't it?

At least that's the behavior in PHP < 8.0, when count() returned 0 if null is passed.

Suggested change

	if ( ! is_countable( $each_child_attrs ) ) {
	continue;
	}
	if ( 0 !== count( $each_child_attrs ) ) {
	if ( null !== $each_child_attrs && 0 !== count( $each_child_attrs ) ) {

[sirreal]

I think you're right. I thought it only contained a foreach with another get_attribute_names_with_prefix() but it contains another conditional block.

That other get_attribute_names_with_prefix has the same problem where it lacks a null check.

[sirreal]

👋 @hugosolar Just checking in, are you able to finish this up or would you like some help? The next release is approaching and it would be nice to get this fix in place.

[hugosolar]

@sirreal I've pushed the fix that seems to work better regarding the tests I've made here
Also, added one test to verify if </br> is breaking _process_directive function
I tested it locally and it's passing but not sure why it's failing in the pipelines
would you help me to figure what's the issue here?

The error is throwing this

Parse error: syntax error, unexpected ')' in /var/www/tests/phpunit/tests/interactivity-api/wpInteractivityAPI.php on line 1272

checked that line but can't see anything wrong with it

[hugosolar]

Thanks for the help @sirreal !
I think this is ready for a CR