css/cssom/insertRule-font-face.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>insertRule with font-face rule</title>
<link rel="help" href="https://drafts.csswg.org/cssom/#dom-cssstylesheet-insertrule">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<!-- Regression test for https://github.com/jsdom/jsdom/issues/3979 -->

<style></style>

<script>
"use strict";

test(() => {
  const styleSheet = document.styleSheets[0];

  styleSheet.insertRule(
    "@font-face{font-family:fcicons;font-style:normal;font-weight:400;" +
    "src:url(\"data:application/x-font-ttf;charset=utf-8;base64,AAA=\") format(\"truetype\")}",
    0
  );

  assert_equals(styleSheet.cssRules.length, 1, "Stylesheet should have one rule");
  assert_equals(styleSheet.cssRules[0].constructor.name, "CSSFontFaceRule");
}, "insertRule with font-face rule should not throw");
</script>