Discovery Testing the Game of Life (Part 4)

This is a series which explores the two schools of test-driven development (Detroit-school TDD and London-school TDD), and introduces an iteration on London-school we call "Discovery Testing".

In this concluding episode, we'll do one last Collaborator test to break up the role of replacing individual cells a little further. Then, we'll (finally!) pivot into classical TDD to drive out the logical leaf node that, via a pure function with no dependencies, that implements the four rules of Conway's Game of Life.

[StephenTurley]

I'm curious. Why don't you mock your value objects in the higher level collaborator tests? Seems like you are just verifying input and output between collaborators and the implementation of the value object doesn't matter. You would also have the added benefit that your value object constructors can change without breaking your higher level tests.

[letsdeveloper]

Hey Justin, thanks for this series! I especially like part 1, because you're clarifying lots of terminology and what you see as the differences between the TDD schools. Part 4 was a bit disappointing though, because you take many shortcuts, because dinner... So you throw TDD overboard when you're lacking time? No offense, I know this happens a lot. It's just that I'd have liked to see you do this last part like you actually need to keep working on that code tomorrow ;)

[cedriclhomme]

Thank you so much for sharing this. It gives an other example that you can compare to the GOOS' one.
Do yours Eclipse templates are available somewhere?