fontface-size-adjust-descriptor.html

<!DOCTYPE html>
<title>Tests that the sizeAdjust attribute of FontFace works</title>
<meta charset="utf-8">
<link rel="author" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-font-loading/#fontface-interface">
<link rel="help" href="https://drafts.csswg.org/css-fonts-4/#font-size-adjust-desc">
<link rel="match" href="fontface-size-adjust-descriptor-ref.html">
<script>
const ahem = new FontFace(
    'Ahem-normal',
    'local("Ahem"), url("/fonts/Ahem.ttf")');
document.fonts.add(ahem);
const large = new FontFace(
    'Ahem-large',
    'local("Ahem"), url("/fonts/Ahem.ttf")',
    {sizeAdjust: "200%", unicodeRange: "U+20,U+41-5A"});
document.fonts.add(large);
</script>
<style>
#target {
  font-family: "Ahem-large", "Ahem-normal";
  font-size: 20px;
  letter-spacing: 10px;
}
</style>

<p>The first and fourth characters should be double-sized:</p>
<div id="target">
  FooBar
</div>

chromium/third_party/blink/web_tests/external/wpt/css/css-font-loading/fontface-size-adjust-descriptor.html