This is the exception that we raise when we find an invalid request. By default, the full details of this exception will be displayed to the browser in development mode. In production mode it will be intercepted, and a 404 Not Found response will be displayed to the user.

This means that if you are using the exception_notification plugin to get emails about exceptions while running in production mode, then you will not get an email when your application encounters bad requests. This is intentional, since bad requests in production are not necessarily an indicator of a bug in your program, and your mailbox can quickly fill up if your visitors are using out-of-date bookmarks, or if someone links to your site incorrectly.

If you would rather have the assertions in this plugin result in status 500 errors, then edit init.rb in the plugin root and comment out the call to alias_method_chain.