fix(role): ignore invalid `aria-labelledby` attributes (#33667)

packages/playwright-core/src/server/injected/roleUtils.ts

@@ -383,7 +383,11 @@ export function getAriaLabelledByElements(element: Element): Element[] | null {
   const ref = element.getAttribute('aria-labelledby');
   if (ref === null)
     return null;
-  return getIdRefs(element, ref);
+  const refs = getIdRefs(element, ref);
+  // step 2b:
+  // "if the current node has an aria-labelledby attribute that contains at least one valid IDREF"
+  // Therefore, if none of the refs match an element, we consider aria-labelledby to be missing.
+  return refs.length ? refs : null;
 }
 
 function allowsNameFromContent(role: string, targetDescendant: boolean) {

tests/library/role-utils.spec.ts

@@ -495,6 +495,16 @@ test('should not include hidden pseudo into accessible name', async ({ page }) =
   expect.soft(await getNameAndRole(page, 'a')).toEqual({ role: 'link', name: 'hello hello' });
 });
 
+test('should ignore invalid aria-labelledby', async ({ page }) => {
+  await page.setContent(`
+    <label>
+      <span>Text here</span>
+      <input type=text aria-labelledby="does-not-exist">
+    </label>
+  `);
+  expect.soft(await getNameAndRole(page, 'input')).toEqual({ role: 'textbox', name: 'Text here' });
+});
+
 function toArray(x: any): any[] {
   return Array.isArray(x) ? x : [x];
 }