chromium/third_party/blink/web_tests/external/wpt/shadow-dom/focus-navigation/focus-navigation-slot-with-tabindex.html

<!DOCTYPE html>
<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>
<p>
  document tree: [i0 -> [x-foo]]<br>
  x-foo's shadow tree: [j1 -> [s1] -> [s2] -> j2 ->[x-bar]]<br>
  x-bar's shadow tree: [[s3] -> k1]<br>
  slot #s1: [i1 -> i2]<br>
  slot #s2: [i3]<br>
  slot #s3: [l1 -> l2]<br><br>
  <b>v1 ideal nav forward:  [i0 -> j1 -> i1 -> i2 -> i3 -> j2 -> x-bar -> l1 -> l2 -> k1]</b><br>
</p>

<input id='i0' tabindex=0 value='i0'>
<div id='x-foo'>
  <input id='i2' slot='s1' tabindex=2 value='i2'>
  <input id='i1' slot='s1' tabindex=1 value='i1'>
  <input id='i3' slot='s2' tabindex=3 value='i3'>
  <template data-mode='open'>
    <div id='x-bar' tabindex=5>
      <input id='l2' slot='s3' tabindex=2 value='l2'>
      <input id='l1' slot='s3' tabindex=1 value='l1'>
      <template data-mode='open'>
        <slot id='s3' name='s3' tabindex=1></slot>
        <input id='k1' tabindex=2 value='k1'>
      </template>
    </div>
    <input id='j1' tabindex=1 value='j1'>
    <slot id='s2' name='s2' tabindex=3></slot>
    <slot id='s1' name='s1' tabindex=2></slot>
    <input id='j2' tabindex=4 value='j2'>
  </template>
</div>

<script>
'use strict';

promise_test(async () => {
    let xfoo = document.getElementById('x-foo');
    convertTemplatesToShadowRootsWithin(xfoo);

    let elements = [
        'i0',
        'x-foo/j1',
        'i1',
        'i2',
        'i3',
        'x-foo/j2',
        'x-foo/x-bar',
        'x-foo/l1',
        'x-foo/l2',
        'x-foo/x-bar/k1',
    ];

    await assert_focus_navigation_bidirectional(elements);
}, 'Slots tabindex should be considred in focus navigation.');
</script>