css/cssom/rule-restrictions.html

<!doctype html>
<meta charset="utf-8">
<title>CSSOM Should correctly honor property restrictions</title>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1665816">
<link rel="help" href="https://drafts.csswg.org/css-page-3/#conform-partial">
<link rel="help" href="https://drafts.csswg.org/css-animations/#keyframes">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  @page {
    margin-top: 10px;
    transform: scale(1);
  }

  @keyframes foo {
    from {
      margin-top: 10px;
      animation-name: none;
    }
  }
</style>
<script>
test(function() {
  let rule = document.styleSheets[0].cssRules[0];
  assert_equals(rule.type, CSSRule.PAGE_RULE, "Should be a page rule");
  assert_equals(rule.style.length, 1, "Transform doesn't quite apply to pages");
  assert_equals(rule.style.marginTop, "10px", "Should have a margin-top declaration");
  rule.style.setProperty("transform", "scale(1)");
  assert_equals(rule.style.getPropertyValue("transform"), "", "Shouldn't have been able to set the transform property via setProperty");
  assert_equals(rule.style.length, 1, "Shouldn't have been able to set transform via setProperty");
  rule.style.cssText = "margin-bottom: 10px; transform: scale(1);";
  assert_equals(rule.style.length, 1, "Should not have been able to set transform via cssText");
  assert_equals(rule.style.marginBottom, "10px", "Should have a margin-bottom declaration");
}, "@page");

test(function() {
  let rule = document.styleSheets[0].cssRules[1].cssRules[0];
  assert_equals(rule.type, CSSRule.KEYFRAME_RULE, "Should be a keyframe rule");
  assert_equals(rule.style.length, 1, "animation-name doesn't apply to keyframes");
  assert_equals(rule.style.marginTop, "10px", "Should have a margin-top declaration");
  rule.style.setProperty("animation-name", "none");
  assert_equals(rule.style.getPropertyValue("animation-name"), "", "Shouldn't have been able to set the animation-nameproperty via setProperty");
  assert_equals(rule.style.length, 1, "Shouldn't have been able to set animation-name via setProperty");
  rule.style.cssText = "margin-bottom: 10px; animation-name: none;";
  assert_equals(rule.style.length, 1, "Should not have been able to set animation-name via cssText");
  assert_equals(rule.style.marginBottom, "10px", "Should have a margin-bottom declaration");

}, "@keyframe");
</script>