>You're assuming that for instance the library is correctly setup and won't crapout because a system requirement is not met. Or that no other external factor wi

>You're assuming that for instance the library is correctly setup and won't crapout because a system requirement is not met. Or that no other external factor will interfere with the result (e.g. your library is hooked to an API) Correct, and if that isn't the case then that's a problem with the library, not my code. In C# I've had none of the issues you just mentioned with libraries, with the exception of ones that expect some specific native DLL to be present that the C# library calls into. And unit testing won't save you from that issue because the system you're running your tests on isn't the same as the system prod is running on. To be frankly honest I question how much you know/understand about languages with strong type systems based on your comments.