<!DOCTYPE html>
<body contenteditable></body>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

document.body.focus();
document.execCommand("InsertHTML", true, "<img></img>");
document.execCommand("SelectAll");
document.execCommand("Underline");
document.execCommand("InsertText", true, "foo");
document.body.textContent = `The underlined text should be 'foo': '${document.querySelector("U").textContent}'`;
</script>