BUGFIX: template-no-empty-headings — recognize boolean aria-hidden

lib/rules/template-no-empty-headings.js

@@ -1,17 +1,37 @@
 const HEADINGS = new Set(['h1', 'h2', 'h3', 'h4', 'h5', 'h6']);
 
+function isAriaHiddenTruthy(attr) {
+  if (!attr) {
+    return false;
+  }
+  const value = attr.value;
+  // Valueless or empty-string attribute — <h1 aria-hidden />. Per HTML boolean
+  // attribute semantics (and jsx-a11y/vue-a11y convention), presence = truthy.
+  if (!value || (value.type === 'GlimmerTextNode' && value.chars === '')) {
+    return true;
+  }
+  if (value.type === 'GlimmerTextNode') {
+    return value.chars === 'true';
+  }
+  if (value.type === 'GlimmerMustacheStatement' && value.path) {
+    if (value.path.type === 'GlimmerBooleanLiteral') {
+      return value.path.value === true;
+    }
+    if (value.path.type === 'GlimmerStringLiteral') {
+      return value.path.value === 'true';
+    }
+  }
+  return false;
+}
+
 function isHidden(node) {
   if (!node.attributes) {
     return false;
   }
   if (node.attributes.some((a) => a.name === 'hidden')) {
     return true;
   }
-  const ariaHidden = node.attributes.find((a) => a.name === 'aria-hidden');
-  if (ariaHidden?.value?.type === 'GlimmerTextNode' && ariaHidden.value.chars === 'true') {
-    return true;
-  }
-  return false;
+  return isAriaHiddenTruthy(node.attributes.find((a) => a.name === 'aria-hidden'));
 }
 
 function isComponent(node) {

tests/lib/rules/template-no-empty-headings.js

@@ -43,6 +43,14 @@ ruleTester.run('template-no-empty-headings', rule, {
     '<template><h1><this.Heading /></h1></template>',
     '<template><h2><@heading /></h2></template>',
     '<template><h3><ns.Heading /></h3></template>',
+
+    // aria-hidden as a boolean / valueless / empty / mustache attribute — all
+    // should exempt the heading (aligns with jsx-a11y / vue-a11y treatment of
+    // boolean HTML attributes).
+    '<template><h1 aria-hidden></h1></template>',
+    '<template><h1 aria-hidden=""></h1></template>',
+    '<template><h1 aria-hidden={{true}}></h1></template>',
+    '<template><h1 aria-hidden="true">Visible to sighted only</h1></template>',
   ],
   invalid: [
     {