“As we were saying, up-front testing really isn’t testing at all. It is really up-front design through the analysis of our tests. Can we take this testing even further? When XP came out and suggested doing unit tests, many of us realized that if we combined a series of unit tests together, we could get the equivalent of automated acceptance testing.”
“By the way, there may be certain arguments for not writing and maintaining a set of automated tests. We don’t think we would agree with them, or at least, in virtually all cases we are fairly sure we wouldn’t. However, there is little argument that can be made for not at least specifying the tests first. This is because you are going to have to specify them at some time. You might as well do it at the time it provides the greatest value.”
Reference: “Essential Skills for the Agile Developer”, Alan Shalloway, Scott Bain, Ken Pugh, Amir Kolsky, Addison-Wesley, ISBN 978-0-321-54373-8