mozilla-release/testing/web-platform/tests/notifications/event-onerror-denied-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Notification.onerror (permission=denied)</title>
<link rel="author" title="Apple Inc." href="http://www.apple.com/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
setup({ explicit_timeout: true })
Notification.requestPermission()
if (Notification.permission != "denied") {
    alert("TEST NOT RUN. Change your browser settings so that notifications"
        + " for this origin are blocked, and then reload this page.")
} else {
    async_test(function (t) {
        t.step(function () {
            var notification = new Notification("New Email Received")
            notification.onerror = function(e) {
                assert_equals(Object.prototype.toString.call(e), "[object Event]")
                assert_equals(e.type, "error")
                Notification.requestPermission()
                t.done()
            }
        })
    })
}
</script>