[justlevine]

What?

This PR fixes an issue in gutenberg_get_block_style_variation_name_from_class() where an array would be returned even if the variation name was not matched in the CSS class string.

This is due to the fact that preg_match_all() will always set $matches[1], and instead uses an empty string if no match is found.

Why?

While this issue was surfaced by PHPStan (via #66693) it can be remediated independently as part of #66598

How?

Testing Instructions

Testing Instructions for Keyboard

Screenshots or screencast

Before	After

[github-actions]

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[westonruter]

🤖 Comment by Claude Opus 5.5

trunk was merged in, and 632f393 replaces the approach here with a sync of wp_get_block_style_variation_name_from_class() as it stands in core after r63890 (Core-66162). Core returns $matches[1] as-is, since preg_match_all() always populates it with an array, so the ?? is dropped rather than turning an empty result into null. Core's unit tests expect an empty array for a string without a variation, so returning null there would diverge from core. The only caller, gutenberg_render_block_style_variation_support_styles(), checks ! $variations, which treats both the same.

The docblock and signature now match core too: a string|null parameter, a native ?array return type, and a conditional @phpstan-return that resolves to list<non-empty-string> when a string is passed. This fixes the two PHPStan level 5 errors on this function and introduces none. Since the function is now identical to core's, the No Core Sync Required label was added.

[github-actions]

🤖 PR meta 🤖

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Co-authored-by: justlevine <justlevine@git.wordpress.org>
Co-authored-by: westonruter <westonruter@git.wordpress.org>

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[westonruter]

Only difference between core and Gutenberg now is the function name itself:

--- core.txt	2026-10-25 13:36:57
+++ gutenberg.txt	2026-10-25 13:36:35
@@ -7,7 +7,7 @@
  * @return string[]|null The block style variation names (empty if none found), or null if a string was not supplied.
  * @phpstan-return ( $class_string is string ? list<non-empty-string> : null )
  */
-function wp_get_block_style_variation_name_from_class( $class_string ): ?array {
+function gutenberg_get_block_style_variation_name_from_class( $class_string ): ?array {
 	if ( ! is_string( $class_string ) ) {
 		return null;
 	}