From abfb58421e0867ead650171f0b78669ce8f8fa6e Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 3 Sep 2026 09:25:50 -0400
Subject: [PATCH] Preserve hidden accessibility support text

---
 .../Style/SourceBlockAttributeProjector.php     | 14 ++++++++++++++
 .../unit/inert-closed-state-interactions.php    | 17 +++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/php-transformer/src/HtmlToBlocks/Style/SourceBlockAttributeProjector.php b/php-transformer/src/HtmlToBlocks/Style/SourceBlockAttributeProjector.php
index 31d45415..278bd861 100644
--- a/php-transformer/src/HtmlToBlocks/Style/SourceBlockAttributeProjector.php
+++ b/php-transformer/src/HtmlToBlocks/Style/SourceBlockAttributeProjector.php
@@ -58,6 +58,9 @@ public function project(
         if ( 'core/group' === $name && $facts->isAuthorLayoutItem ) {
             $attrs['className'] = SourceDom::mergeClassNames((string) ($attrs['className'] ?? ''), self::CSS_OWNED_LAYOUT_ITEM_CLASS);
         }
+        if ( in_array($name, array( 'core/group', 'core/paragraph' ), true) && self::isHiddenAccessibilitySupportElement($sourceElement) ) {
+            $attrs['className'] = SourceDom::mergeClassNames((string) ($attrs['className'] ?? ''), self::HIDDEN_RICH_TEXT_MARKER_CLASS);
+        }
         if ( 'core/group' === $name && $this->isAtomicInlineChildFlow($sourceElement, $innerBlocks) ) {
             $attrs['className'] = SourceDom::mergeClassNames((string) ($attrs['className'] ?? ''), self::CSS_OWNED_INLINE_FLOW_CLASS);
         }
@@ -90,6 +93,17 @@ public function project(
         return $attrs;
     }
 
+    private static function isHiddenAccessibilitySupportElement(DOMElement $element): bool
+    {
+        $identity = strtolower(SourceDom::attr($element, 'id') . ' ' . SourceDom::attr($element, 'class'));
+        if ( 1 !== preg_match('/(?:a11y|accessib|screen[-_]?reader|sr[-_]?only|visually[-_]?hidden)/', $identity) ) {
+            return false;
+        }
+
+        $style = strtolower(SourceDom::attr($element, 'style'));
+        return 1 === preg_match('/(?:^|;)\s*(?:display\s*:\s*none|visibility\s*:\s*hidden)\s*(?:!important)?\s*(?:;|$)/', $style);
+    }
+
     public function sourceProjectionClassName(DOMElement $element, SourceBlockAttributeProjectionContext $context, string $className = ''): string
     {
         $sourceTagMarker = $context->selectorProjections->tagMarker(strtolower($element->tagName));
diff --git a/php-transformer/tests/unit/inert-closed-state-interactions.php b/php-transformer/tests/unit/inert-closed-state-interactions.php
index db7c8a94..decd312b 100644
--- a/php-transformer/tests/unit/inert-closed-state-interactions.php
+++ b/php-transformer/tests/unit/inert-closed-state-interactions.php
@@ -335,6 +335,23 @@
     $boundaryMarkerAfterAuthor
 );
 
+$hiddenNavigationSupport = <<<'HTML'
+<wix-dropdown-menu>
+  <nav><ul><li><a href="/">Home</a></li></ul><div id="menu-hiddenA11ySubMenuIndication" style="display:none">Use tab to navigate through the menu items.</div></nav>
+</wix-dropdown-menu>
+HTML;
+
+$hiddenNavigationSupportResult = ( new HtmlTransformer() )->transform($hiddenNavigationSupport)->toArray();
+$hiddenNavigationSupportMarkup = (string) ($hiddenNavigationSupportResult['serialized_blocks'] ?? '');
+$hiddenNavigationSupportBeforeAuthor = $cssContent($hiddenNavigationSupportResult, 'before-author', 'both');
+$assert(
+    str_contains($hiddenNavigationSupportMarkup, 'Use tab to navigate through the menu items.')
+        && str_contains($hiddenNavigationSupportMarkup, 'blocks-engine-hidden-richtext-marker')
+        && str_contains($hiddenNavigationSupportBeforeAuthor, ':where(.blocks-engine-hidden-richtext-marker){display:none}'),
+    'an explicitly hidden navigation accessibility support group retains its hidden state',
+    $hiddenNavigationSupportMarkup . "\n" . $hiddenNavigationSupportBeforeAuthor
+);
+
 if ( $failures > 0 ) {
     fwrite(STDERR, "inert closed-state interactions: {$failures} failed, {$passes} passed\n");
     exit(1);