chromium/third_party/blink/web_tests/external/wpt/html/semantics/popovers/popover-shadowhost-focus.html

<!DOCTYPE html>
<link rel=author href="mailto:[email protected]">
<link rel=help href="https://github.com/whatwg/html/issues/8994">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<div popover=auto tabindex=0 data-test="autofocus=true, delegatesfocus=false" autofocus class=should-be-focused>
  <template shadowrootmode=open>
    <button autofocus>autofocus button</button>
  </template>
</div>

<!-- The autofocus popover is what focus() gets called on, but since it has a
  delegatesFocus shadowroot, focus() itself goes into the shadowroot. -->
<div popover=auto tabindex=0 data-test="autofocus=true, delegatesfocus=true" autofocus>
  <template shadowrootmode=open shadowrootdelegatesfocus>
    <button autofocus class=should-be-focused>autofocus button</button>
  </template>
</div>

<div popover=auto tabindex=0 data-test="autofocus=false, delegatesfocus=false">
  <template shadowrootmode=open>
    <button autofocus>autofocus button</button>
  </template>
</div>

<div popover=auto tabindex=0 data-test="autofocus=false, delegatesfocus=true">
  <template shadowrootmode=open shadowrootdelegatesfocus>
    <button autofocus>autofocus button</button>
  </template>
</div>

<script>
document.querySelectorAll('body > [popover]').forEach(popover => {
  promise_test(async () => {
    const expectedFocusedElement = (popover.matches('.should-be-focused') ? popover : null)
      || popover.querySelector('.should-be-focused')
      || popover.shadowRoot.querySelector('.should-be-focused')
      || document.body;

    popover.showPopover();

    let actualFocusedElement = document.activeElement;
    if (actualFocusedElement.shadowRoot && actualFocusedElement.shadowRoot.activeElement) {
      actualFocusedElement = actualFocusedElement.shadowRoot.activeElement;
    }

    popover.hidePopover();

    // Resetting focus may happen asynchronously
    await new Promise(resolve => requestAnimationFrame(resolve));

    assert_equals(actualFocusedElement, expectedFocusedElement);
  }, popover.getAttribute('data-test'));
});
</script>