Test-Driven Development - Are you doing it right?

Recently I have been doing test-driven development (TDD) exclusively in both Java and C#, and I have made great progress in doing it the right way. I was fortunate to learn the right way from Uncle Bob who my employer invited for a TDD in-house training course for our engineering team.

So how do you know that you are doing it right?

Here are the signs that you are on the right path:

• You are writing more tests than ever before 
• Your test coverage is creeping up to > 90%
• You create a test class before creating the class under test
• You write a failing unit test before making any code changes
• Your test classes are longer (more lines) than the class under test
• You start to feel itchy when you write a line of code that is not making a test pass
• You are more confident in the code you are writing
• You are refactoring your tests
• You are not deploying and debugging every time you change the code
• You are debugging tests rather than production code
  

Doing TTD is not easy and requires that you stop following old habits and force yourself to do it properly for a few weeks. For me it was a slow off-and-on process, but as I do more and more of it, I find that I am getting my development speed back, with an added boost of confidence provided by over 90% code coverage. Yes, I have tests to prove it!