<!DOCTYPE html>
<html>
<body>
<p>Test passes if you see a single 100px by 100px green box below.</p>
<svg style="width: 100px; height: 100px;" viewbox="0 0 100 100">
    <defs>
        <path id="path1" d="M0,50 L100,50 Z" />
        <path id="path2" d="M0,-5 L100,-5 Z" />
    </defs>
    <rect x="0" y="0" width="100" height="100" fill="green"></rect>
    <text>
        <textPath href="#path1">FAIL</textPath>
    </text>
</svg>
<script>

if (window.testRunner)
    testRunner.waitUntilDone();

window.onload = () => {
    requestAnimationFrame(() => {
        document.querySelector('textPath').setAttribute('href', '#path2');
        if (window.testRunner)
            requestAnimationFrame(() => testRunner.notifyDone());
    });
}

</script>
</body>
</html>