I just created a Manager that deals with a SuperClass that is extended all over the code base and registered with some sort of SuperClassManager (SCM).

Now I would like to test my Manager that is aware of only the SuperClass. I tried to create a concrete SCM, however, that depends on a third party library and therefore I failed to do that in my jUnit test. Now the option is to mock all instances of this SCM.

All is good until now, however, when my Manager deals with the SCM, it returns children of the SuperClass that my Manager does not know or care about. Nevertheless, the identities of these children are vital for my tests (for equality, etc.).

Since I cannot use the concrete SCM, I have to mock the results of calls to the appropriate functions of the SCM, however, this means that my tests and therefore my Manager need to know and care about the children of the SuperClass.

Checking the code base, there does not seem to be a more appropriate location for my test (that already maintains the appropriate real dependencies).

Is it worth it to introduce unnecessary dependencies for the sake of unit testing?