chromium/third_party/blink/web_tests/fast/css/font-feature-settings-assert.html

<!DOCTYPE html>
<style>
    #x {
        -webkit-font-feature-settings: "liga";
        font-feature-settings: "liga";
        transition: color 1s;
    }
</style>
<div id="x">PASS if this test didn't assert.<div>
<script>
    if (window.testRunner) {
        testRunner.dumpAsText();
        testRunner.waitUntilDone();
    }

    x.offsetTop;
    x.style.color = "green";

    if (window.testRunner) {
        requestAnimationFrame(() => {
            testRunner.notifyDone();
        });
    }
</script>