css/css-values/inherit-function-invalidation.html

<!DOCTYPE html>
<title>CSS Values: The inherit() function (invalidation)</title>
<link rel="help" href="https://drafts.csswg.org/css-values-5/#inherit-notation">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<main id=main>
</main>

<template id=parent_change_unregistered>
  <style>
    #outer {
      --z: 2;
    }
    #target {
      z-index: inherit(--z);
    }
  </style>
  <div id=outer>
    <div id=target>
    </div>
  </div>
</template>
<script>
  test((t) => {
    main.append(parent_change_unregistered.content.cloneNode(true));
    t.add_cleanup(() => { main.replaceChildren(); });
    assert_equals(getComputedStyle(target).zIndex, '2');
    assert_equals(getComputedStyle(target).getPropertyValue('--z'), '2');
    outer.style.setProperty('--z', '4');
    assert_equals(getComputedStyle(target).zIndex, '4');
    assert_equals(getComputedStyle(target).getPropertyValue('--z'), '4');
  }, 'inherit() invalidates when values changes on parent element, inherited');
</script>

<!-- Like the previous test, but #target is buried deeper. -->
<template id=parent_change_unregistered_deep>
  <style>
    #outer {
      --z: 2;
    }
    #target {
      z-index: inherit(--z, 7);
    }
  </style>
  <div id=outer>
    <div>
      <div>
        <div>
          <div id=target></div>
        </div>
      </div>
    </div>
  </div>
</template>
<script>
  test((t) => {
    main.append(parent_change_unregistered_deep.content.cloneNode(true));
    t.add_cleanup(() => { main.replaceChildren(); });
    assert_equals(getComputedStyle(target).zIndex, '2');
    outer.style.setProperty('--z', '4');
    assert_equals(getComputedStyle(target).zIndex, '4');
  }, 'inherit() invalidates when values changes on parent element, inherited, deeper');
</script>

<template id=parent_change_registered>
  <style>
    @property --z {
      syntax: "<integer>";
      inherits: false;
      initial-value: 0;
    }
    #outer {
      --z: 2;
    }
    #target {
      z-index: inherit(--z, 7);
    }
  </style>
  <div id=outer>
    <div id=target>
    </div>
  </div>
</template>
<script>
  test((t) => {
    main.append(parent_change_registered.content.cloneNode(true));
    t.add_cleanup(() => { main.replaceChildren(); });
    assert_equals(getComputedStyle(target).zIndex, '2');
    assert_equals(getComputedStyle(target).getPropertyValue('--z'), '0');
    outer.style.setProperty('--z', '4');
    assert_equals(getComputedStyle(target).zIndex, '4');
    assert_equals(getComputedStyle(target).getPropertyValue('--z'), '0');
  }, 'inherit() invalidates when values changes on parent element, non-inherited');
</script>