<!DOCTYPE html>
<html>
<head>
<script>
if (window.internals)
    window.internals.settings.setShouldAllowDesignSystemUIFonts(true);
</script>
</head>
<body>
This test makes sure that the design system UI fonts don't work unless the shouldAllowDesignSystemUIFonts preference is set. The test passes if all the text below is bold.
<div>
<div style="display: inline-block; font: bold 72px '-apple-system-ui-serif';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '-apple-system-ui-monospaced';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '-apple-system-ui-rounded';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '.AppleSystemUIFontSerif';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '.SF NS Mono';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '.SF UI Mono';">HeJllo</div>
<div style="display: inline-block; font: bold 72px '.AppleSystemUIFontRounded';">HeJllo</div>
</div>
</body>
</html>