In the rare cases we find a library that doesn't have a typescript definition, we just do:

   declare var Thing : any;

In a global definition file.

Pro tip. We've got a lot of mixed js and ts at the moment and when you're really lazy you can take advantage of how every object is a dictionary in js and just do something like `window["notification"]` instead of window.notification, which resolves to an 'any' type in ts.

Obviously you should try and minimise that usage, but it's a useful trick to know.