@BeforeClass rule about junit4

[aisrael]

I'm recklessly trying to do this myself:

1. Added org.junit.rules.ClassRule, with apply(Statement next, TestClass testClass).
2. Modified ParentRunner#classBlock() to call withClassRules() which looks for fields that are public, static, and implement ClassRule.
3. For each of those fields, call apply() to append to the statement 'chain'.
4. Also, modify BlockJUnit4ClassRunner to only apply @Rule fields that implement MethodRule.

Am I on the right track?

Here're my changes:
http://github.com/AlistairIsrael/junit/commit/79ef5a7e1d7fa144cc81c9414f4791aaea8b3d75

For the record, it works. I've successfully split a Derby+Hibernate+DbUnit @Rule into a static, ClassRule that initializes Derby and Hibernate, and a regular MethodRule that delegates to DbUnit loading/unloading of database fixtures using a local 'build'.

[brolund]

Hi,
I think I did a similar thing in my fork http://github.com/brolund/junit

In addition to what you describe, my goal was to be able to register rules for methods, classes and suites on a root suite and then be able to propagate them to an entire suite hierarchy. My primary reason is to be able to generate documentation like in my pet project
http://www.agical.com/bumblebee/bumblebee_doc.html
but without having to make my own suite implementations.

Of course, this approach could be used for a number of reasons. Suite-scope dependency injection, logging, resource creation and management. It won't work well for running parallel tests (as of now).

[aisrael]

Yup, the natural extension of rules on methods, then rules on classes, would've been rules on suites. My other suggestion along this line was to let rules be declaratively specified, without the end-user having to instantiate a no-arg, non-interactive rule.

I also noticed you used the RunNotifier to pass around 'ancestry' because of the "lack of a context-like structure in JUnit". I ran into a similar issue when I experimented with declarative, class-level rules. There was no easy way for the ParentRunner to pass the test instance, and instances of rules to children.

So I stopped myself there, and contented myself with the smallest change that could apply to my still limited needs. I tend to agree, though, that JUnit might need some kind of "test context" to pass around in the future.

[maxb]

Hi. I've just discovered the problem of a lack of a class-based @rule myself, and located this message: http://tech.groups.yahoo.com/group/junit/message/22522 - I notice there's been no activity on this issue since. Is there any likelyhood of it landing soon? Is there anything I can do to help it along?

[aisrael]

Just an update, updated my class rules tree and 'pulled' from latest JUnit master in to http://github.com/AlistairIsrael/junit/tree/435195876d559ec780e21f4f53e8db6849a65b23

[dsaff]

Thanks. Kent and I will review Monday, if not before.

[dsaff]

Fixed and accepted at HEAD

[dsaff]

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