css/css-values/tree-counting/sibling-function-media-query.tentative.html

<!DOCTYPE html>
<title>CSS Values and Units Test: sibling-index() and sibling-count() invalid in media queries</title>
<link rel="help" href="https://drafts.csswg.org/css-values-5/#tree-counting">
<link rel="help" href="https://drafts.csswg.org/mediaqueries-5/#width">
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/10982">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style id="test_sheet">
  #target {
    background-color: green;
  }
  @media (width > CALC(0px * sibling-index())) {
    #target { background-color: red; }
  }
  @media (width > CALC(0px * sibling-count())) {
    #target { background-color: red; }
  }
</style>
<div id="target"></div>
<script>
  test(() => {
    assert_equals(getComputedStyle(target).backgroundColor, "rgb(0, 128, 0)");
  }, "sibling-index() and sibling-count() are not valid in @media queries");

  test(() => {
    let rules = test_sheet.sheet.cssRules;
    assert_equals(rules.length, 3);
    assert_equals(rules[1].media.mediaText, "(width > CALC(0px * sibling-index()))");
    assert_equals(rules[2].media.mediaText, "(width > CALC(0px * sibling-count()))");
  }, "@media queries with sibling-index() and sibling-count() as general-enclosed");

</script>