As introduced before, Jupiter is the name given to the new programming model of JUnit 5, described in detail in chapter 3, JUnit 5 standard tests and chapter 4, Simplifying testing with advanced JUnit features, together with the extension model. The extension model allows to extend the Jupiter programming model with custom additions. Thanks to this, third-party frameworks (such as Spring or Mockito, to name a few) can achieve interoperability with JUnit 5 in a seamless way. The extensions provided by these frameworks will be studied in chapter 5, Integration of JUnit 5 with external frameworks. In the current section, we analyze the general performance of the extension model and also the extensions provided out of the box in JUnit 5.
In contrast to former extension points in JUnit 4 (that is, test runners and rules...