<!DOCTYPE html>
<html hidden>
<head>
<style>
html, head, style {
    display: block;
}
</style>
</head>
<script>
    document.designMode = "on";
    document.execCommand("selectAll");
    document.execCommand("italic");
    document.execCommand("justifyLeft");
    document.documentElement.removeAttribute("hidden");
</script>
<body>
This test passes if it does not crash.
</body>
</html>
