MethodRule only gets invoked for the test method, however for a change where you would otherwise extend BlockJUnit4ClassRunner and override withBefores, you can't achieve the same with a Rule.

MethodRule should have a sub-interface e.g. LifeCycleAwareRule that allows a rule to change the test instance before the @before block is run.

One example is unitils @SpringBeanByType, these must be injected before the @before block runs, but with Rule this is not possible