18.2. Aspects of JPA testing

When you use JPA (or any other ORM software) in your application, you’re delegating the task of persisting objects to and from the database to an external tool. But in the end, the results are the same as if you wrote the persistence code yourself. So, in its essence, JPA testing isn’t much different than testing regular database access code, and hence most of the techniques explained in chapter 17 apply here. A few differences and caveats are worth mentioning though, and we cover them in the next subsections. But first, let’s consider some aspects of JPA testing.

What Should Be Tested?

JPA programming could be divided in two parts: entities mapping and API calls. Initially, you need to define how your objects will be mapped to the database tables, typically through the use of Java annotations. Then you use an EntityManager object to send these objects to or from the database: you can create objects, delete them, fetch them using JPA queries, and so on.