TDD: How Did You Start? What Is Stopping You From Starting?

Based on the folks who came to the session, most people have yet to start doing TDD.

The session started with a story from someone who was doing TDD. They had heard about it in school. However, they didn't feel that they got TDD until they started working for a company where TDD is emphasized. There they had access to mentors that could show them how TDD works in practice. After practicing coding using TDD they shared that it now felt strange to code without tests. The words they used were scary and fragile.

Not surprisingly, given that the T in TDD stands for Test, the next discussion was about the relationship between QA and development once the development group starts to practice TDD. We all agreed that cultural changes are needed in any organization where development adopts TDD. The kinds of QA activities that produce value change when development starts to practice TDD.

The rest of the session was an examination of the costs and benefits of TDD.

Costs of TDD

• Time to write tests
• Can't change UI without breaking tests
• Can't change code without breaking tests
• Takes time to learn how to do TDD

Benefits of TDD

• Less regression
• Less time spent debugging
• Emergent design
• Simpler design
• Freedom to change code