Tests alert events when a shadow DOM element's own visibility and role change simultaneously.
Key steps:
- Shadow content element exists as IGNORED (visibility:hidden on itself)
- Element's visibility changes to visible AND gains role="alert" (same element, same update)
- Change type: NODE_CHANGED (element updates in place)
- NotifyNodeAttributesHaveBeenChanged returns early for ignored transitions
- OnIgnoredChanged fires Event::ALERT
@UIA-WIN-DENY:*
@UIA-WIN-ALLOW:SystemAlert*
@UIA-WIN-ALLOW:LiveRegion*
-->
<!DOCTYPE html>
<html>
<head>
<title>Alert on Property Change Test</title>
</head>
<body>
<test-alert id="alert"></test-alert>
<script>
class TestAlert extends HTMLElement {
constructor() {
super();
this.attachShadow({ mode: 'open' });
this.shadowRoot.innerHTML = `
<style>
#container {
visibility: hidden;
}
#container.visible {
visibility: visible;
}
</style>
<div id="container">
Settings saved successfully!
</div>
`;
}
show() {
const container = this.shadowRoot.getElementById('container');
container.classList.add('visible');
container.setAttribute('role', 'alert');
}
}
customElements.define('test-alert', TestAlert);
function go() {
const alert = document.getElementById('alert');
alert.show();
return false;
}
</script>
</body>
</html>
