chromium/third_party/blink/web_tests/external/wpt/custom-elements/state/state-css-selector-shadow-dom.html

<!doctype html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="timeout" content="long" />
    <meta
      name="author"
      title="Keith Cirkel"
      href="mailto:[email protected]"
    />
    <link rel="help" href="https://html.spec.whatwg.org/multipage/custom-elements.html#custom-state-pseudo-class" />
    <title>:state() css selector applies in shadow roots</title>

    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
  </head>
  <body>
    <custom-state id="myCE"> I should be green </custom-state>
    <style></style>
    <script>
      customElements.define(
        "custom-state",
        class extends HTMLElement {
          connectedCallback() {
            this.elementInternals = this.attachInternals();
            const css = new CSSStyleSheet();
            css.replaceSync(`
              :host {
                color: #f00;
              }
              :host(:state(green)) {
                color: #0f0;
              }
            `);
            this.attachShadow({ mode: "open" }).adoptedStyleSheets.push(css);
          }
        },
      );

      test(function () {
        assert_false(myCE.elementInternals.states.has("green"));
        assert_equals(
          getComputedStyle(myCE).getPropertyValue("color"),
          "rgb(255, 0, 0)",
        );
      }, "state selector has no influence when state is not applied");

      test(function (t) {
        myCE.elementInternals.states.add("green");
        t.add_cleanup(() => {
          myCE.elementInternals.states.delete("green");
        });
        assert_true(myCE.elementInternals.states.has("green"));
        assert_equals(
          getComputedStyle(myCE).getPropertyValue("color"),
          "rgb(0, 255, 0)",
        );
      }, "state selector has influence when state is applied");

      test(function (t) {
        myCE.elementInternals.states.add("foo");
        t.add_cleanup(() => {
          myCE.elementInternals.states.delete("foo");
        });
        assert_false(myCE.elementInternals.states.has("green"));
        assert_true(myCE.elementInternals.states.has("foo"));
        assert_equals(
          getComputedStyle(myCE).getPropertyValue("color"),
          "rgb(255, 0, 0)",
        );
      }, "state selector only applies on given ident");
    </script>
  </body>
</html>