For a project as complex as the wanderer reconstruction, testing is crucial. There is some lightweight unit testing in the framework classes, but there are no unit tests in the entity classes, so some serious testing is now needed to make sure that the game itself works properly.
One problem with this is that the original version of the game doesn't provide a precise specification to test against. The same problem would occur with a newly designed game, where a developer might have an intuitive notion of what should happen in various situations, but no precise specification of how each type of entity should behave.
A good way round this is to implement replay testing. A game level, real or simplified, is set up and played manually to check that everything happens as desired. The user's commands and the resulting actions that appear on screen are recorded into a file. Then, whenever desired, that game can be replayed. That is, the commands can be extracted from the file, offered to the system as if they came from the user, and the resulting actions on the screen checked against the ones recorded. With care, this reply testing can be fully automatic, without displaying anything graphically. In other words, regression testing of manual play takes the place of testing against a specification.
There is no proof that the wanderer reconstruction exactly matches the original game. In fact it doesn't. There are known details where it would not be sensible to blindly copy the original game. However, replay testing does provide proof that all of the original 60 levels are solvable in the reconstruction, in the same way that they might have been solved in the original game. The later stages of development involved making sure that each of the 60 levels in turn worked properly. Each level was very likely to introduce a new type of entity, or new examples of interaction between entities. Replay testing was critical to ensure that previous levels still worked properly.
It is desirable to have a graphical user interface in place to do the
recording of the play. In practice, in the reconstruction of the wanderer game,
replay testing wasn't done until a working prototype of the user interface was
available. However, it is essential that the replay testing itself should not
involve graphics. The general mechanism is therefore implemented in the
Level class, and the game-specific testing is driven by a
non-graphics Test class in the wanderer package.
Typing make Test ensures that all the entity classes are compiled,
and then runs the entire suite of replay tests.