In this chapter, we took a look at how tests guide the final steps to create the complete app. We used tests to drive the implementation of the navigation between the view controllers of the app. We also implemented the serialization and deserialization of the to-do items.

Finally, we used functional tests to make sure that the app worked from the user perspective, and we found a critical bug by doing so.

In the next chapter, we will take a look at the code coverage of our tests. This means that we will get a better insight into how much of the code is covered by tests. We will also set up continuous integration in order to improve the feedback about our code.