<!DOCTYPE html>
<link rel="help" href="https://crbug.com/977953" />
<script type="text/javascript" src="/resources/testharness.js"></script>
<script type="text/javascript" src="/resources/testharnessreport.js"></script>
<style>
    @font-face {}
</style>
<script>
    test(() => {
        let rule = document.styleSheets[0].cssRules[0];
        rule.style.backgroundPosition = 'bottom 10px right 20px';
    }, 'Do not crash when setting an invalid @font-face descriptor via CSSOM');
</script>