css/css-syntax/charset-is-not-a-rule.html

<!doctype html>
<title>@charset isn't a valid rule and should be dropped</title>
<meta name="author" title="Tab Atkins-Bittner">
<link rel=help href="https://drafts.csswg.org/css-syntax/#charset-rule">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
@charset "utf-8";
@charset "utf-8";
foo { color: blue; }
@charset "utf-8";
</style>
<script>
test(()=>{
    assert_equals(document.styleSheets[0].cssRules.length, 1)
}, "@charset isn't a valid rule and shouldn't show up in the OM");
</script>