fix: use classifyAttribute for tabindex + disabled (rows d3, d6, t6, t7)

Author: johanrd

lib/rules/template-no-aria-hidden-on-focusable.js

@@ -2,6 +2,7 @@
 
 const { isNativeElement } = require('../utils/is-native-element');
 const { getStaticAttrValue } = require('../utils/static-attr-value');
+const { classifyAttribute } = require('../utils/glimmer-attr-presence');
 
 function findAttr(node, name) {
   return node.attributes?.find((a) => a.name === name);
@@ -63,22 +64,12 @@ function isDisabledFormControl(node, tag) {
     return false;
   }
   const attr = findAttr(node, 'disabled');
-  if (!attr) {
-    return false;
-  }
-  // Per docs/glimmer-attribute-behavior.md, ONLY bare-mustache boolean-false
-  // (`disabled={{false}}`) renders as omitted at runtime — concat
-  // (`disabled="{{false}}"`) and string-literal (`disabled={{"false"}}`) forms
-  // still render the attribute as present and the control IS disabled.
-  const v = attr.value;
-  if (
-    v?.type === 'GlimmerMustacheStatement' &&
-    v.path?.type === 'GlimmerBooleanLiteral' &&
-    v.path.value === false
-  ) {
-    return false;
-  }
-  return true;
+  // Per docs/glimmer-attribute-behavior.md (rows d3, d6 plus cross-attribute
+  // observation on falsy-coercion), bare-mustache falsy literals on a boolean
+  // HTML attribute cause Glimmer to omit the attribute at runtime. We use
+  // classifyAttribute so the runtime-rendered presence drives the answer
+  // rather than AST-presence.
+  return classifyAttribute(attr).presence === 'present';
 }
 
 // Narrow rule-local "keyboard-focusable" check. Intentionally distinct from
@@ -98,8 +89,11 @@ function isKeyboardFocusable(node, getTextAttrValueFn) {
   }
 
   // Any tabindex (including "-1") makes the element at least programmatically
-  // focusable — still a keyboard-trap risk under aria-hidden.
-  if (findAttr(node, 'tabindex')) {
+  // focusable — still a keyboard-trap risk under aria-hidden. Use
+  // classifyAttribute so bare `{{false}}` / `{{null}}` / `{{undefined}}`
+  // (rows t6, t7) — which Glimmer omits at runtime — are NOT treated as
+  // having a tabindex.
+  if (classifyAttribute(findAttr(node, 'tabindex')).presence === 'present') {
     return true;
   }
 

tests/lib/rules/template-no-aria-hidden-on-focusable.js

@@ -47,6 +47,14 @@ ruleTester.run('template-no-aria-hidden-on-focusable', rule, {
     '<template><button disabled aria-hidden="true">Click me</button></template>',
     '<template><input disabled aria-hidden="true" /></template>',
 
+    // Bare-mustache falsy on tabindex (rows t6, t7) — Glimmer omits the
+    // attribute at runtime, so the element is NOT focusable from tabindex
+    // and aria-hidden isn't trapping anything. AST-presence check would
+    // have false-positive flagged these.
+    '<template><div tabindex={{false}} aria-hidden="true"></div></template>',
+    '<template><div tabindex={{null}} aria-hidden="true"></div></template>',
+    '<template><div tabindex={{undefined}} aria-hidden="true"></div></template>',
+
     // Components — we don't know if they render a focusable element.
     '<template><CustomBtn aria-hidden="true" /></template>',
 
@@ -148,6 +156,17 @@ ruleTester.run('template-no-aria-hidden-on-focusable', rule, {
       output: null,
       errors: [{ messageId: 'noAriaHiddenOnFocusable' }],
     },
+    // Same shape with bare-mustache null/undefined — also omitted (rows d6 + cross-attr observation).
+    {
+      code: '<template><button aria-hidden="true" disabled={{null}}>click</button></template>',
+      output: null,
+      errors: [{ messageId: 'noAriaHiddenOnFocusable' }],
+    },
+    {
+      code: '<template><button aria-hidden="true" disabled={{undefined}}>click</button></template>',
+      output: null,
+      errors: [{ messageId: 'noAriaHiddenOnFocusable' }],
+    },
     {
       code: '<template><button aria-hidden="TRUE"></button></template>',
       output: null,