Assign generic role to aside tag within the sectioning content elements

https://bugs.webkit.org/show_bug.cgi?id=235065
rdar://problem/87391915

Reviewed by Tyler Wilcock.

This change assigns a generic ARIA role to <aside> elements when they are nested
within <aside>, <article>, <section>, or <nav> elements, aligning with the spec
(https://w3c.github.io/html-aam/#el-aside).
This follows the discussion in w3c/html-aam#512

Additionally, it introduces a check to return LandmarkComplementary when an <aside>
tag has an explicit accessible name.

* LayoutTests/imported/w3c/web-platform-tests/html-aam/roles-contextual-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/html-aam/roles-contextual.html:
* Source/WebCore/accessibility/AccessibilityNodeObject.cpp:
(WebCore::AccessibilityNodeObject::determineAccessibilityRoleFromNode const):

Canonical link: https://commits.webkit.org/270509@main

LayoutTests/imported/w3c/web-platform-tests/html-aam/roles-contextual-expected.txt

@@ -12,15 +12,17 @@ x
 x
 x
 x
+x
 
 PASS el-a
 PASS el-aside-in-section-with-name
+PASS el-aside-in-section-with-role
 PASS el-aside-ancestorbodymain
 PASS el-footer-ancestorbody
 PASS el-header-ancestorbody
 PASS el-section
 PASS el-a-no-href
-FAIL el-aside-in-section-without-name assert_false: Computed Role: "complementary" does not match any of the acceptable role strings in ["generic", "", "none"]: <aside data-testname="el-aside-in-section-without-name" class="ex-generic">x</aside> expected false got true
+PASS el-aside-in-section-without-name
 PASS el-footer
 PASS el-header
 PASS el-section-no-name

LayoutTests/imported/w3c/web-platform-tests/html-aam/roles-contextual.html

@@ -25,6 +25,7 @@
 <nav>
   <aside data-testname="el-aside-in-section-with-name" data-expectedrole="complementary" aria-label="x" class="ex">x</aside>
   <aside data-testname="el-aside-in-section-without-name" class="ex-generic">x</aside>
+  <aside data-testname="el-aside-in-section-with-role" data-expectedrole="complementary" class="ex" role="complementary">x</aside>
 </nav>
 <aside data-testname="el-aside-ancestorbodymain" data-expectedrole="complementary" class="ex">x</aside>
 
@@ -51,4 +52,4 @@
 </script>
 
 </body>
-</html>
+</html>

Source/WebCore/accessibility/AccessibilityNodeObject.cpp

@@ -440,8 +440,20 @@ AccessibilityRole AccessibilityNodeObject::determineAccessibilityRoleFromNode(Tr
         return AccessibilityRole::LandmarkMain;
     if (node()->hasTagName(navTag))
         return AccessibilityRole::LandmarkNavigation;
-    if (node()->hasTagName(asideTag))
+    if (node()->hasTagName(asideTag)) {
+        if (ariaRoleAttribute() == AccessibilityRole::LandmarkComplementary)
+            return AccessibilityRole::LandmarkComplementary;
+        // The aside element should not assume the complementary role when nested
+        // within the sectioning content elements.
+        // https://w3c.github.io/html-aam/#el-aside
+        if (isDescendantOfElementType({ asideTag, articleTag, sectionTag, navTag })) {
+            // Return LandmarkComplementary if the aside element has an accessible name.
+            if (hasAttribute(aria_labelAttr) || hasAttribute(aria_labelledbyAttr) || hasAttribute(aria_descriptionAttr) || hasAttribute(aria_describedbyAttr))
+                return AccessibilityRole::LandmarkComplementary;
+            return AccessibilityRole::Generic;
+        }
         return AccessibilityRole::LandmarkComplementary;
+    }
     if (node()->hasTagName(searchTag))
         return AccessibilityRole::LandmarkSearch;