chromium/third_party/blink/web_tests/external/wpt/shadow-dom/focus-navigation/focus-navigation-slot-nested-2levels.html

<!DOCTYPE html>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="resources/shadow-dom.js"></script>
<script src="resources/focus-utils.js"></script>
<div id="log"></div>

<input id='i0'>
<div id='outer'>
  <template data-mode='open'>
    <input id='outer-before'>
    <slot></slot>
    <input id='outer-after'>
  </template>
  <div id='dummy1'></div>
  <div id='nested1'>
    <template data-mode='open'>
      <input id='inner-before'>
      <div id='inner-div' tabindex='0'><slot></slot></div>
      <input id='inner-after'>
    </template>
    <div id='dummy2'></div>
    <div id='nested2'>
      <template data-mode='open'>
        <input id='innermost-before'>
        <slot></slot>
        <input id='innermost-after'>
      </template>
      <input id='innermost1'>
      <input id='innermost2'>
    </div>
    <span>button</span>
  </div>
</div>
<input id='i1'>

<script>
promise_test(async () => {
  var outer = document.querySelector('#outer');
  convertTemplatesToShadowRootsWithin(outer);

  var elements = [
    'i0',
    'outer/outer-before',
    'nested1/inner-before',
    'nested1/inner-div',
    'nested2/innermost-before',
    'innermost1',
    'innermost2',
    'nested2/innermost-after',
    'nested1/inner-after',
    'outer/outer-after',
    'i1'
  ];

  await assert_focus_navigation_bidirectional(elements);
}, 'Focus controller should treat each slot as a focus scope.');
</script>