Setup

The detailed example from Chapter 2, ​Test-Driven Development: A First Example​ shows what Test-Driven Development should look like in practice. As we worked through the example, we touched on a considerable number of concepts and good practices. (You might also have chosen to skip that chapter if you’re already familiar with TDD.) This chapter explores these topics in more detail, providing a bit more background and rationale behind each.

• The definition of unit

• The TDD cycle of red-green-refactor

• The three rules of TDD

• Why you should never skip observing test failure

• Mind-sets for success

• Mechanics for success

When you’ve worked through each of these topics, you’ll be well grounded in the process and concepts behind TDD.