Summary

In this chapter, we compared unit tests with its siblings: integration and Sintegration tests. We listed test doubles and gave an example of each, and we have also seen xUnit and NSubstitute in action.

Our journey with understanding unit testing and test doubles will not stop here, but we will cover more examples of the two topics across the rest of the book.

So far, you can consider the experience from this chapter to take you to TDD level 3 out of 5! And now, you should be able to write a basic unit test that uses test doubles.

We have not covered the advantages and disadvantages of unit testing—yes, it has disadvantages! We have also not covered how TDD relates to unit testing and the best practices of unit testing because this is the role of the next chapter, Test-Driven Development Explained.