## Summary of Changes in version 4.9

### ClassRule

The `ClassRule` annotation extends the idea of method-level Rules, adding static fields that can affect the operation of a whole class. Any subclass of `ParentRunner`, including the standard `BlockJUnit4ClassRunner` and `Suite` classes, will support `ClassRule`s.

For example, here is a test suite that connects to a server once before all the test classes run, and disconnects after they are finished:

    @RunWith(Suite.class)
    @SuiteClasses({A.class, B.class, C.class})
    public class UsesExternalResource {
        public static Server myServer= new Server();

        @Rule
        public static ExternalResource resource= new ExternalResource() {
            @Override
            protected void before() throws Throwable {
                myServer.connect();
            };

            @Override
            protected void after() {
                myServer.disconnect();
            };
        };
    }

### TestRule

In JUnit 4.9, fields that can be annotated with either `@Rule` or `@ClassRule` should be of type `TestRule`. The old `MethodRule` type, which only made sense for method-level rules, will still work, but is deprecated.

Most built-in Rules have been moved to the new type already, in a way that should be transparent to most users. `TestWatchman` has been deprecated, and replaced by `TestWatcher`, which has the same functionality, but implements the new type.

`TestRule` is an abstract base class, and its abstract `apply` method is protected. In order to apply `TestRule`s to a `Statement`, use the `RunRules` class in `org.junit.rules` (thanks to `@kcooney`)

### LICENSE checked in

The Common Public License that JUnit is released under is now included in the source repository.

### Bug fixes

- github#98: assumeTrue() does not work with expected exceptions

- github#74: Categories + Parameterized

  In JUnit 4.8.2, the Categories runner would fail to run correctly if any contained test class had a custom Runner with a structure significantly different from the built-in Runner. With this fix, such classes can be assigned one or more categories at the class level, and will be run correctly. Trying to assign categories to methods within such a class will flag an error.

- github#163: Bad comparison failure message when using assertEquals(String, String)

  Thanks to `@kcooney`

### Minor changes

- Backed out unused folder "experimental-use-of-antunit", replaced by bash-based script at build_tests.sh

- Made MultipleFailureException public, to assist extension writers. Thanks to `@kcooney`