LayoutTests/fast/events/mutation-in-DOMCharacterDataModified.html

foo
<script type="text/javascript">
if (window.testRunner)
    testRunner.dumpAsText();

document.addEventListener("DOMCharacterDataModified", () => {
    document.body.textContent = "This test passes if it doesn't crash";
});
onload = () => {
    document.body.firstChild.data = "bar";
};
</script>