Notifer throws error in dev console if no message is supplied

[ycombinator]

Steps to reproduce

Run this code:

import Notifier from 'ui/notify/notifier';

const notifier = new Notifier({ location: 'Some location' });
notifier.error();

Observed behavior

The developer console shows this error + stack trace:

TypeError: Cannot read property 'stack' of undefined
    at formatStack (notifier.js:248)
    at Notifier.error (notifier.js:421)
    at Notifier.wrapper [as error] (index.js:3095)
    at watch_list.js:71
    at processQueue (angular.js:14745)
    at angular.js:14761
    at Scope.$eval (angular.js:15989)
    at Scope.$digest (angular.js:15800)
    at angular.js:16028
    at completeOutstandingRequest (angular.js:5507)

Expected behavior

One of two approaches could be taken here:

• Either the lack of argument to the notifier.error() method should be handled gracefully and the notifier shouldn't be displayed at all, or
• The method should do a validity check and throw a meaningful Error. If uncaught, this would still result in bubbling up to the developer console but at least the message would be a bit more developer-friendly.