Migrating from JUnit 4 to JUnit 5: replacing rules with the extension model. Part 1
JUnit 5 Jupiter is the combination of the new programming model (annotations, classes, methods) and extension model for writing tests and extensions in JUnit 5. The Jupiter sub-project provides a test engine for running Jupiter based tests on the platform. In contrast to the previously existing runners and rules extension points in JUnit 4, the JUnit Jupiter extension model consists of a single, coherent concept: the Extension API.