I'm writing an application that is using Drupal APIs to connect to an external database and doing a bunch of stuff with this data (reading/writing/deleting). I was wondering if there are any best practices for writing simpletests in Drupal 7 with this kind of application. I know simpletest basically installs a new instance of Drupal, then uses this sandbox environment to do testing. However none of the schema for this external database is defined in drupal.
Any tips on how I can test against this database, and not have a bunch of left over data when tests complete?