March 11, 2018

...Learn TDD with Codemanship

Proposing The xUnit "Meta-Kata"

A while back I ruminated on refactoring old-fashioned "test it all with a main method" test code (like we did back in the day) into the xUnit unit test framework pattern.

It occurred to me that this might make a good code kata. TDD a well-known kata (e.g., FizzBuzz, Bowling Game, "Rock, Paper, Scissors"), but starting without a unit testing framework doing it all in a single main method.

As the code evolves, refactor the test code to remove code smells like methods testing more than one thing, classes testing more than one "unit" or "feature" (depending on how you roll), high-level modules that depend directly on low-level test fixtures, multiple tests being different examples of the same test, and so on.

It could be an interesting exercise in discovering frameworks. Perhaps it'll take multiple katas for a complete xUnit framework to reveal itself, just as so many great and useful frameworks don't really take shape until they've been reused a few times on other problems.

It might also be an exercise in applying the TDD discipline on two problems simultaneously; a test of your Craft Fu.

Really, it would be a kata within a kata: a meta-kata, if you like. And as such, I think it could be really interesting and rather challenging. I'll hopefully be giving it a go - well, probably a few goes - when I pair with my "apprentice" Will Price soon. When I think we've cracked it, I'll post a screencast and the code (with version history, so you can play it back).




Posted 5 months, 4 days ago on March 11, 2018