LayoutTests/accessibility/custom-elements/orientation.html

<!DOCTYPE html>
<html>
<body>
<script src="../../resources/js-test.js"></script>
<script src="../../resources/accessibility-helper.js"></script>
<custom-radio-group id="group-1"></custom-radio-group>
<custom-radio-group id="group-2" aria-orientation="horizontal"></custom-radio-group>
<script>

customElements.define('custom-radio-group', class CustomGrid extends HTMLElement {
    constructor()
    {
        super();
        const internals = this.attachInternals();
        internals.role = 'radiogroup';
        internals.ariaOrientation = 'vertical';
    }
});

description("This tests that aria fallback roles work correctly.");
if (!window.accessibilityController)
    debug('This test requires accessibilityController');
else {
    shouldBeEqualToString('accessibilityController.accessibleElementById("group-1").orientation', 'AXOrientation: AXVerticalOrientation');
    shouldBeEqualToString('accessibilityController.accessibleElementById("group-2").orientation', 'AXOrientation: AXHorizontalOrientation');
}

</script>
</body>
</html>