Justin Duke

Forcing functions in everything

Kelly Sutton wrote a great article about how TDD impacts software design:

Design Pressure is the little voice in the back of your head made manifest by a crappy test with too much setup. It’s a force that says when your tests become hard to write, you need to refactor your code.

I think this is absolutely correct, and touches on a larger concept that I’ve been internalizing over the past few months – that the best methods for evaluating the soundness of a codebase come from activities adjacent to the codebase. (Or, to use fewer syllables, if it sucks to do something with the code, then the code probably sucks.)

  • Is it tedious and frustrating to create documentation for a codebase? That’s a sign that the codebase is disjointed and documentation tooling is inadequate.
  • Are tests painful to write or run? That’s a sign that the interfaces and abstractions you’ve chosen are incorrect.
  • Are code reviews disjointed or overly cumbersome? That’s a sign of improper organization and poor structuring.
  • Is it a non-trivial task to deploy new changes or onboard a new developer? That’s a sign your environment is on the wrong side of the spectrum between pleasant and eldritch.

All the things that are commonly loathed as tasks – keeping an accurate, performant test suite, having comprehensive documentation, thorough and probing code reviews – are bellwethers of a codebase’s overall health.

Obviously, they’re good tasks to do in of themselves, just like TDD provides the lower order benefit of ensuring a certain level of correctness, but they give you the opportunity to examine your codebase through a lens other than “the person writing the code”, which is even more valuable.

Or, to quote Anne Lamont:

It’s like discovering that while you thought you needed the tea ceremony for the caffeine, what you really needed was the tea ceremony.

Liked this post? You should subscribe to my newsletter and follow me on Twitter.
© 2017 Justin Duke • All rights reserved • I hope you have a nice day.