<!DOCTYPE html>
<link rel=author href="mailto:jarhar@chromium.org">
<link rel=help href="https://github.com/whatwg/html/pull/9093">
<link rel=help href="https://drafts.csswg.org/css-position-4/#overlay">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<title>CSS Position Test: User agent style for overlay</title>

<style>
div {
  overlay: auto;
}
</style>

<body>
<script>
test(() => {
  const div = document.createElement('div');
  document.body.appendChild(div);
  div.style.overlay = 'auto';
  assert_equals(getComputedStyle(div).overlay, 'none');
}, 'HTML elements should have overlay:none !important from the user-agent.');

test(() => {
  const svg = document.createElement('svg');
  document.body.appendChild(svg);
  svg.style.overlay = 'auto';
  assert_equals(getComputedStyle(svg).overlay, 'none');
}, 'SVG elements should have overlay:none !important from the user-agent.');

test(() => {
  const nullNamespace = document.createElementNS(null, 'div');
  document.body.appendChild(nullNamespace);
  assert_equals(getComputedStyle(nullNamespace).overlay, 'none');
}, 'Null namespace elements should have overlay:none !important from the user-agent.');

test(() => {
  const weirdNamespace = document.createElementNS('hello world', 'div');
  document.body.appendChild(weirdNamespace);
  assert_equals(getComputedStyle(weirdNamespace).overlay, 'none');
}, 'Arbitrary namespace elements should have overlay:none !important from the user-agent.');
</script>
