You can do that but I think youíre probably going to be happier testing the application itself instead of components; or testing the components from within the application. Controllers need to have a notion of the Catalyst context. Essentially, they donít even properly exist except as part of a request dispatch. A controller endpoint cannot naturally do anything outside of that.
What youíre doing is akin to trying to check subs inside a script instead of the script itself. It can be done but itís weird given the, well, context of the code. Catalyst controllers arenít code that can be run alone, only within and by the app. Side-note: models and views differ here. Catalyst only adds configuration and access affordances for those.
Catalyst testing is really extremely good and flexible. Only Mojo is better, easier. It doesnít require any (system, standalone, external) server or special environment or anything.