chromium/third_party/blink/web_tests/accessibility/aom-relation-properties.html

<!DOCTYPE HTML>
<script src="../resources/gc.js"></script>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>

<!--

Accessibility Object Model
Explainer: https://github.com/WICG/aom/blob/gh-pages/explainer.md
Spec: https://wicg.github.io/aom/spec/

-->

<script>
test(function(t) {
    assert_true(internals.runtimeFlags.accessibilityObjectModelEnabled);
}, "Make sure that Accessibility Object Model is enabled");
</script>

<div role="listbox" id="listbox" tabindex=0>
  <div role="option" id="option1">Option 1</div>
  <div role="option" id="option2">Option 2</div>
  <div role="option" id="option3">Option 3</div>
</div>

<script>
test(function(t) {
    var listbox = document.getElementById("listbox");
    var option1 = document.getElementById("option1");
    listbox.focus();
    var axListbox = accessibilityController.accessibleElementById("listbox");
    var axOption1 = accessibilityController.accessibleElementById("option1");
    assert_false(axOption1.isSelected);
    assert_equals(axListbox.ariaActiveDescendantElement(), undefined);

    listbox.accessibleNode.activeDescendant = option1.accessibleNode;

    assert_equals(axListbox.ariaActiveDescendantElement(), undefined);

    // Previously, Active Descendant also makes the option selected. This check
    // is here to verify that this no longer happens now that AccessibleNode is
    // becoming uncoupled from the Accessibility Tree.
    assert_false(axOption1.isSelected);
}, "AccessibleNode.activeDescendant");
</script>