chromium/third_party/blink/web_tests/external/wpt/css/css-conditional/container-queries/custom-property-style-query-change.html

<!doctype html>
<title>CSS Container Queries Test: custom property style query changes</title>
<link rel="help" href="https://drafts.csswg.org/css-conditional-5/#style-container">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/cq-testcommon.js"></script>
<style>
  #container { container-name: my-container; }
  #child, #grandchild { color: red; }
  @container style(--target: child) {
    #child { color: green; }
  }
  @container my-container style(--target: grandchild) {
    #grandchild { color: green; }
  }
</style>
<div id="container">
  <div id="child"></div>
  <div>
    <div id="grandchild"></div>
  </div>
</div>
<script>
  setup(() => assert_implements_container_queries());

  const green = "rgb(0, 128, 0)";
  const red = "rgb(255, 0, 0)";

  test(() => {
    assert_equals(getComputedStyle(child).color, red);
    assert_equals(getComputedStyle(grandchild).color, red);
  }, "Initially no queries match.");

  test(() => {
    container.style.setProperty("--target", "child");
    assert_equals(getComputedStyle(child).color, green);
    assert_equals(getComputedStyle(grandchild).color, red);
  }, "Target child");

  test(() => {
    container.style.setProperty("--target", "grandchild");
    assert_equals(getComputedStyle(child).color, red);
    assert_equals(getComputedStyle(grandchild).color, green);
  }, "Target grandchild");
</script>

<style>
  @property --length {
    syntax: "<length>";
    inherits: false;
    initial-value: 0px;
  }

  #reg_container {
    container-name: my-reg-container;
    font-size: 50px;
  }
  #reg_child, #reg_grandchild { color: red; }
  @container style(--length: 100px) {
    #reg_child { color: green; }
  }
  @container my-reg-container style(--length: 200px) {
    #reg_grandchild { color: green; }
  }
</style>
<div id="reg_container">
  <div id="reg_child"></div>
  <div>
    <div id="reg_grandchild"></div>
  </div>
</div>
<script>
  test(() => {
    assert_equals(getComputedStyle(reg_child).color, red);
    assert_equals(getComputedStyle(reg_grandchild).color, red);
  }, "Initially no queries for registered property match.");

  test(() => {
    reg_container.style.setProperty("--length", "2em");
    assert_equals(getComputedStyle(reg_child).color, green);
    assert_equals(getComputedStyle(reg_grandchild).color, red);
  }, "Registered property query child");

  test(() => {
    reg_container.style.setProperty("--length", "200px");
    assert_equals(getComputedStyle(reg_child).color, red);
    assert_equals(getComputedStyle(reg_grandchild).color, green);
  }, "Registered property query grandchild");
</script>