RE: Automated testing of Notifications
When developing automated tests, there are external UI actions unavailable.
Notifications, might be an example. After SEND, the notification is displayed in the UI and if these has been specified with an action (ADDACTION) then users might have or not performed the action to click into the link.
This action is a UI action like, e.g. invoking an external dialog to upload a file, and test toolkit should not be able to catch it.
Maybe you could think of adding another separate testing module to mimic the action that would have been performed with the ADDACTION. That is the only solution that I could see, personally.