BeforeEachCallback defines the API for Extensions that wish to provide additional behavior to tests before an individual test and any user-defined setup methods (e.g., @BeforeEach methods) for that test have been executed.

Concrete implementations often implement AfterEachCallback as well. If you do not wish to have your callbacks wrapped around user-defined setup and teardown methods, implement BeforeTestExecutionCallback and AfterTestExecutionCallback instead of BeforeEachCallback and AfterEachCallback.

Constructor Requirements

Consult the documentation in Extension for details on constructor requirements.

Wrapping Behavior

JUnit Jupiter guarantees wrapping behavior for multiple registered extensions that implement lifecycle callbacks such as BeforeAllCallback, AfterAllCallback, BeforeEachCallback, AfterEachCallback, BeforeTestExecutionCallback, and AfterTestExecutionCallback.

That means that, given two extensions Extension1 and Extension2 with Extension1 registered before Extension2, any "before" callbacks implemented by Extension1 are guaranteed to execute before any "before" callbacks implemented by Extension2. Similarly, given the two same two extensions registered in the same order, any "after" callbacks implemented by Extension1 are guaranteed to execute after any "after" callbacks implemented by Extension2. Extension1 is therefore said to wrap Extension2.