inert/inert-on-slots.tentative.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>inert inside ShadowRoot affects slotted content</title>
    <link rel="author" title="Alice Boxhall" href="aboxhall@chromium.org">
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
</head>
<body>
  <div>Button 1 should be inert, and Button 2 should not be inert.</div>
  <div id="shadow-host">
    <button slot="slot-1" id="button-1">Button 1 (inert)</button>
    <button slot="slot-2" id="button-2">Button 2 (not inert)</button>
  </div>
  <script>
    /*
    Eventual flattened tree structure:

    <div id="shadow-host">
      #shadow-root (open)
      | <slot id="slot-1" inert>
      :   <button id="button-1">Button 1</button> <!-- slotted -->
      | </slot>
      | <slot id="slot-2">
      :   <button id="button-2">Button 2</button> <!-- slotted -->
      | </slot>
    </div>
    */

    const shadowHost = document.getElementById("shadow-host");
    const shadowRoot = shadowHost.attachShadow({ mode: "open" });

    const slot1 = document.createElement("slot");
    slot1.name = "slot-1";
    slot1.inert = true;
    shadowRoot.appendChild(slot1);

    const slot2 = document.createElement("slot");
    slot2.name = "slot-2";
    shadowRoot.appendChild(slot2);

    function testCanFocus(selector, canFocus) {
      const element = document.querySelector(selector);
      let focusedElement = null;
      element.addEventListener("focus", function() { focusedElement = element; }, false);
      element.focus();
      assert_equals((focusedElement === element), canFocus);
    }

    test(() => {
      testCanFocus("#button-1", false);
      testCanFocus("#button-2", true);
    }, "inert inside ShadowRoot affects slotted content");
  </script>
</body>
</html>