The issue I run into most often is that a system or set of functions I want to test relies on or resides in a complicated object that requires proper initializa

The issue I run into most often is that a system or set of functions I want to test relies on or resides in a complicated object that requires proper initialization. This means that to run tests I need to manually perform all of this initialization, including spoofing complicated internal data structures and whatnot. The fix? Better compartmentalization in a lot of cases. Or writing classes with a viable form of default initialization in mind.