chromium/third_party/blink/web_tests/external/wpt/shadow-dom/slot-fallback-content-005.html

<!DOCTYPE html>
<meta charset="utf-8" >
<meta name="author" title="Di Zhang" href="mailto:[email protected]">
<meta name="assert" content="Remove slot with assigned node, when dynamically created.">
<title>Shadow DOM: Slots and fallback contents</title>
<link rel="match" href="slot-fallback-content-005-ref.html">

<p>Test passes if empty.</p>

<div id="host">
  <slot id="slot1" name="slot1">FAIL</slot>
  <div id="A" slot="slot1">FAIL</div>
</div>

<script>
const shadowRoot = host.attachShadow({ mode: "open" });
shadowRoot.appendChild(slot1);
const s1 = shadowRoot.getElementById('slot1');
s1.remove();

</script>