custom-elements/custom-element-registry/upgrade.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>customElements.upgrade()</title>
<link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
<link rel="help" href="https://html.spec.whatwg.org/multipage/#dom-customelementregistry-upgrade">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
"use strict";

test(() => {
  const el = document.createElement("spider-man");

  class SpiderMan extends HTMLElement {}
  customElements.define("spider-man", SpiderMan);

  assert_false(el instanceof SpiderMan, "The element must not yet be upgraded");

  customElements.upgrade(el);
  assert_true(el instanceof SpiderMan, "The element must now be upgraded");
}, "Upgrading an element directly (example from the spec)");

test(() => {
  const el1 = document.createElement("element-a-1");
  const el2 = document.createElement("element-a-2");
  const container = document.createElement("div");
  container.appendChild(el1);
  container.appendChild(el2);

  class Element1 extends HTMLElement {}
  class Element2 extends HTMLElement {}
  customElements.define("element-a-1", Element1);
  customElements.define("element-a-2", Element2);

  assert_false(el1 instanceof Element1, "element 1 must not yet be upgraded");
  assert_false(el2 instanceof Element2, "element 2 must not yet be upgraded");

  customElements.upgrade(container);
  assert_true(el1 instanceof Element1, "element 1 must now be upgraded");
  assert_true(el2 instanceof Element2, "element 2 must now be upgraded");
}, "Two elements as children of the upgraded node");

test(() => {
  const el1 = document.createElement("element-b-1");
  const el2 = document.createElement("element-b-2");
  const container = document.createElement("div");
  const subContainer = document.createElement("span");
  const subSubContainer = document.createElement("span");
  container.appendChild(subContainer);
  subContainer.appendChild(el1);
  subContainer.appendChild(subSubContainer);
  subSubContainer.appendChild(el2);

  class Element1 extends HTMLElement {}
  class Element2 extends HTMLElement {}
  customElements.define("element-b-1", Element1);
  customElements.define("element-b-2", Element2);

  assert_false(el1 instanceof Element1, "element 1 must not yet be upgraded");
  assert_false(el2 instanceof Element2, "element 2 must not yet be upgraded");

  customElements.upgrade(container);
  assert_true(el1 instanceof Element1, "element 1 must now be upgraded");
  assert_true(el2 instanceof Element2, "element 2 must now be upgraded");
}, "Two elements as descendants of the upgraded node");

test(() => {
  const el1 = document.createElement("element-d-1");
  const el2 = document.createElement("element-d-2");

  const container = document.createElement("div");
  const subContainer = document.createElement("span");
  subContainer.attachShadow({ mode: "open" });
  const subSubContainer = document.createElement("span");
  subSubContainer.attachShadow({ mode: "open" });

  container.appendChild(subContainer);
  subContainer.shadowRoot.appendChild(el1);
  subContainer.shadowRoot.appendChild(subSubContainer);
  subSubContainer.shadowRoot.appendChild(el2);

  class Element1 extends HTMLElement {}
  class Element2 extends HTMLElement {}
  customElements.define("element-d-1", Element1);
  customElements.define("element-d-2", Element2);

  assert_false(el1 instanceof Element1, "element 1 must not yet be upgraded");
  assert_false(el2 instanceof Element2, "element 2 must not yet be upgraded");

  customElements.upgrade(container);
  assert_true(el1 instanceof Element1, "element 1 must now be upgraded");
  assert_true(el2 instanceof Element2, "element 2 must now be upgraded");
}, "Two elements as shadow-including descendants (and not descendants) of the upgraded node");

test(() => {
  const template = document.createElement("template");
  template.innerHTML = `
    <div>
      <element-c-1></element-c-1>
      <element-c-2>
        <element-c-3></element-c-3>
        <span>
          <element-c-4></element-c-4>
        </span>
      </element-c-2>
    </div>
    <element-c-5></element-c-5>
  `;

  // This code feels repetitive but I tried to make it use loops and it became harder to see the correctness.

  const el1 = template.content.querySelector("element-c-1");
  const el2 = template.content.querySelector("element-c-2");
  const el3 = template.content.querySelector("element-c-3");
  const el4 = template.content.querySelector("element-c-4");
  const el5 = template.content.querySelector("element-c-5");

  class Element1 extends HTMLElement {}
  class Element2 extends HTMLElement {}
  class Element3 extends HTMLElement {}
  class Element4 extends HTMLElement {}
  class Element5 extends HTMLElement {}

  customElements.define("element-c-1", Element1);
  customElements.define("element-c-2", Element2);
  customElements.define("element-c-3", Element3);
  customElements.define("element-c-4", Element4);
  customElements.define("element-c-5", Element5);

  assert_false(el1 instanceof Element1, "element 1 must not yet be upgraded");
  assert_false(el2 instanceof Element2, "element 2 must not yet be upgraded");
  assert_false(el3 instanceof Element3, "element 3 must not yet be upgraded");
  assert_false(el4 instanceof Element4, "element 4 must not yet be upgraded");
  assert_false(el5 instanceof Element5, "element 5 must not yet be upgraded");

  customElements.upgrade(template);

  assert_false(el1 instanceof Element1, "element 1 must not yet be upgraded despite upgrading the template");
  assert_false(el2 instanceof Element2, "element 2 must not yet be upgraded despite upgrading the template");
  assert_false(el3 instanceof Element3, "element 3 must not yet be upgraded despite upgrading the template");
  assert_false(el4 instanceof Element4, "element 4 must not yet be upgraded despite upgrading the template");
  assert_false(el5 instanceof Element5, "element 5 must not yet be upgraded despite upgrading the template");

  customElements.upgrade(template.content);

  // Template contents owner documents don't have a browsing context, so
  // https://html.spec.whatwg.org/multipage/custom-elements.html#look-up-a-custom-element-definition does not find any
  // custom element definition.
  assert_false(el1 instanceof Element1, "element 1 must still not be upgraded after upgrading the template contents");
  assert_false(el2 instanceof Element2, "element 2 must still not be upgraded after upgrading the template contents");
  assert_false(el3 instanceof Element3, "element 3 must still not be upgraded after upgrading the template contents");
  assert_false(el4 instanceof Element4, "element 4 must still not be upgraded after upgrading the template contents");
  assert_false(el5 instanceof Element5, "element 5 must still not be upgraded after upgrading the template contents");
}, "Elements inside a template contents DocumentFragment node");
</script>