fix(ui): Ensure hidden passworld field is hidden from a11y tree

.changeset/cold-dodos-lay.md

@@ -0,0 +1,5 @@
+---
+'@clerk/ui': patch
+---
+
+Remove hidden password input from accessibility tree when hidden

packages/ui/src/components/SignIn/SignInStart.tsx

@@ -734,14 +734,26 @@ const InstantPasswordRow = ({
   return (
     <Form.ControlRow
       elementId={field.id}
-      sx={show ? undefined : { position: 'absolute', opacity: 0, height: 0, pointerEvents: 'none', marginTop: '-1rem' }}
+      aria-hidden={show ? undefined : true}
+      sx={
+        show
+          ? undefined
+          : {
+              position: 'absolute',
+              opacity: 0,
+              height: 0,
+              overflow: 'hidden',
+              pointerEvents: 'none',
+              marginTop: '-1rem',
+            }
+      }
     >
       <Form.PasswordInput
         {...field.props}
         actionLabel={show ? localizationKeys('formFieldAction__forgotPassword') : undefined}
         onActionClicked={show ? onForgotPasswordClick : undefined}
-        ref={ref}
         tabIndex={show ? undefined : -1}
+        ref={ref}
       />
     </Form.ControlRow>
   );

packages/ui/src/components/SignIn/__tests__/SignInStart.test.tsx

@@ -573,6 +573,52 @@ describe('SignInStart', () => {
     });
   });
 
+  describe('Instant password field a11y', () => {
+    it('hides the empty instant password field from the a11y tree via aria-hidden', async () => {
+      const { wrapper } = await createFixtures(f => {
+        f.withEmailAddress();
+        f.withPassword({ required: true });
+      });
+      const { container } = render(<SignInStart />, { wrapper });
+
+      const passwordField = container.querySelector('#password-field') as HTMLElement;
+      expect(passwordField).not.toBeNull();
+
+      const row = passwordField.closest('[class*="formFieldRow"]') as HTMLElement;
+      expect(row).toHaveAttribute('aria-hidden', 'true');
+    });
+
+    it('reveals the instant password field when the browser autofills it', async () => {
+      // Simulate the browser's :autofill animation that the component polls for
+      mockGetComputedStyle.mockReturnValue({
+        animationName: 'onAutoFillStart',
+        pointerEvents: 'auto',
+        getPropertyValue: vi.fn().mockReturnValue(''),
+      });
+
+      const { wrapper } = await createFixtures(f => {
+        f.withEmailAddress();
+        f.withPassword({ required: true });
+      });
+      const { container } = render(<SignInStart />, { wrapper });
+
+      const passwordField = container.querySelector('#password-field') as HTMLElement;
+      const row = passwordField.closest('[class*="formFieldRow"]') as HTMLElement;
+
+      // initially hidden from a11y tree until the autofill poll fires
+      expect(row).toHaveAttribute('aria-hidden', 'true');
+
+      await waitFor(
+        () => {
+          expect(row).not.toHaveAttribute('aria-hidden');
+        },
+        { timeout: 2000 },
+      );
+      // Forgot password action only renders once the field is shown
+      screen.getByText(/Forgot password/i);
+    });
+  });
+
   describe('Session already exists error handling', () => {
     it('redirects user when session_exists error is returned during sign-in', async () => {
       const { wrapper, fixtures } = await createFixtures(f => {