Most developers test whether their code works. Far fewer test whether anyone can reach it. I did not. For eighteen months.
Last week a ten minute script found five unreachable features in a game I started three weeks ago. One of them was an entire progression system.
The player paid for it, and nothing in the interface had ever called the function that delivers it.
This week I point the same script at the eighteen month old application sitting on the Microsoft Store, in front of real users.
The check
The check is trivial. List every public method in the layer that holds rules. Search the layer that holds the buttons for each name. Zero matches means dead or unreachable, and you have to find out which. I already know it will find something.
I can point at twenty four separate times I said "that one is done" and was wrong, and every one had the same shape. Nothing crashed.
That is part I never see written down. Every safety net you build is also a place a failure can hide. Fallback image. Default value. Bare except. The green test that never opened the real window. You add them so the thing does not crash, and doing that deletes the only signal you had.
This week
So the week is short. Run the sweep across whole application. Publish the raw count on Friday, whatever it is. Fix what an afternoon fixes, log what it does not, add a ratchet per class so it cannot ship twice.
Friday will tell the truth. If you ran that sweep on your own project today, what is your honest guess for the number?