custom-elements/historical.html

<!doctype html>
<title>Custom Elements historical features</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
test(() => {
  assert_false('registerElement' in document);
}, 'document.registerElement should not exist');

test(() => {
  const dummy = document.createElement("div");
  const shadowRoot = dummy.attachShadow({ mode: "closed" });
  assert_equals(shadowRoot.importNode, undefined);
  assert_equals(shadowRoot.createElement, undefined);
  assert_equals(shadowRoot.createElementNS, undefined);
}, "ShadowRoot doesn't have importNode or createElement[NS]");

test(() => {
  const dummy = document.createElement("div");
  dummy.attachShadow({ mode: "closed", get registry() { throw "FAIL" } });
}, "attachShadow() does not recognize a registry member");
</script>