So far, this book has introduced JUnit and its latest version, 5. We’ve discussed the core classes and methods and presented them in action so that you have a good understanding of how to build your tests efficiently. We’ve emphasized the importance of software architecture in general and shown the significant architectural changes between JUnit 4 and JUnit 5.
This chapter demonstrates how to make the step from JUnit 4 to JUnit 5 inside a project managed by our example company, Tested Data Systems Inc. The company keeps its customer information in a repository and addresses this repository to get the data. In addition, the company needs to track payments and other business rules.