Introduction: Driving Design—TDD and SOLID

So far, we’ve created some basic unit tests that have driven out a simple design for a couple of classes. We’ve experienced how test-driven development (TDD) makes decision-making about design choices central. In order to build out to a larger application, we’re going to need to be able to handle designs of greater complexity. To do that, we’re going to apply some recommended approaches to assessing what makes one design preferable to another.

The SOLID