Doesn't seem that way unfortunately.
I am currently trying to write a basic test for authorizing access to a custom tool and I can't find pretty much anything on testing Nova stuff..
I've found this package https://joshgaber.github.io/NovaUnit , that however has nothing on testing authorization nor custom tools.
For resources and dashboards I've been asserting that I get a 403 on hitting routes, then granting the test user permissions and asserting 200 status. However Tools behave differently, when canSee() method returns false, I get a 404 error page with status 200 instead a 404 or 403... which breaks my process