Collateral Effort Revisited

tottinger — Mon, 11 Jun 2007 20:36:00 -0500

One of the things I love about TDD is that it takes all the scaffolding and collateral effort for creating a class, all indications of bad coupling, and makes them entirely visible. This is also one thing that makes it very hard to start TDD in legacy system.

When you realize that it’s very hard to test a class out-of-context, the right answer is to start decoupling each class so it can be run out-of-context. When we are successful here, tests run very very fast and are easily self-verifying and isolated. It is a beautiful thing even if it follows many ugly hours of painstaking work.

The wrong answer, I’m convinced, is to build a mega-framework for testing that allows you to test in-context. This type of framework typically creates a totally realistic runtime environment (complete with database, configuration files, directories, etc). This approach allows you to think that you can ignore your dependency nightmare. You really can not Mega-test-frameworks take a such a long time to run that developers stop running all the tests all the time. This is a far worse problem than breaking dependencies because it breaks the whole process. Mega-frameworks don’t solve the problem, they only defer the solution until the problem gets worse.

When you are faced this kind of collateral effort, the answer is to work through it, not to sweep it under a rug. Working through it is work, indeed, but this is about doing the right thing not doing the easiest thing.

"Collateral Effort Revisited" by Jason

Thu, 14 Jun 2007 07:50:54 -0500

I completely agree. It doesn’t just apply to fixing your code so it’s more testable, but almost any part of code smells. At some point you’re going to have to pay the piper, no matter how many things you try to sweep under the rug or implement some nifty “noone will have to really fix their design problems if they implement this” type solution.

Object Mentor Blog: Collateral Effort Revisited

Collateral Effort Revisited

"Collateral Effort Revisited" by Jason