When I have a global event handler attached to the main frame, Edge on iOS always seems to throw an error and the event.error object is always NULL. Is this by design?
<!doctype HTML>
<html>
<head>
<title>Global error handler test</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<script type='text/javascript'>
window.addEventListener('error', function(event) {
alert(event.message + " - " + event.error);
});
</script>
</body>
</html>
When viewed in Edge iOS, this will always show an alert showing "Script error. - null". If I intentionally throw an error after adding the handler, then I first get an alert for it with the expected message, but then I also get the generic null error message too.