A set of a unit tests for a project 3+ years old, now fail. It seems the tests themselves have become out of date, and I've wasted time trying to find non existent bugs.
To prevent this happening again, I will update the unit tests to correct values, and want to document why the input data is and expected results are correct.
Any advice and recommendations on best practices to do this, to make it easier for the next guy on this project would be very helpful right now.