2.7. Summary

In this chapter, we covered how to design a system to ensure that it is fully testable. We covered the SOLID principles that can aid your decisions and provide a foundation for you to build your applications. We introduced the various different methods of developer testing such as unit and Test Driven Development. After which, we covered how to take advantage of test doubles to break the dependencies within your system to aid testability. Moving on we discussed test smells and what makes a good test to ensure you have a firm foundation going forward, allowing you to get started writing developer tests.

In the next chapter, we look at applying the techniques discussed to a sample application.