css/css-counter-styles/idlharness.html

<!doctype html>
<title>css-counter-styles IDL tests</title>
<link rel="help" href="https://drafts.csswg.org/css-counter-styles/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/WebIDLParser.js"></script>
<script src="/resources/idlharness.js"></script>

<style>
  @counter-style triangle {
    system: cyclic;
    symbols: ‣;
    suffix: " ";
  }
</style>
<script>
  'use strict';
  idl_test(
    ['css-counter-styles'],
    ['cssom'],
    idl_array => {
      try {
        self.counter = document.styleSheets[0].rules[0];
      } catch (e) {
        // Will be surfaced when counter is undefined below.
      }

      idl_array.add_objects({
        CSSCounterStyleRule: ['counter'],
      });
    }
  );
</script>