[jboss-dev] How can a project run in both AS 4.2.0 and AS 5.0?

[Adrian]

On Thu, 2007-07-19 at 15:28 +0100, Tim Fox wrote:
> But this is a big maintenance hassle - and will mean double the test 
> runs. Our test runs already take forever.
> 
> How do other projects deal with this? Surely we are not the only ones.

Welcome to multiple branches and the N^2 problem.

Like I've said many times before, if you want to avoid the N^2 problem
you need to make sure that;

1) you have a clean integration with the other projects you use and
2) that those other projects have tests for how you use them.

If you do it properly, you should be able to replace those
projects with a "mock" implementation in your tests.

I'd even encourage you to make some tests
with a "pathological mock".

That is, it will "randomly misbehave" so you know your
error handling/reporting and integration is "robust" in the event
of failures beyond your control.

> Or perhaps other projects don't worry about it and "hope for the best" 
> when installed in AS 5.0?

Certainly when people use other people's apis "Willy Nilly"
rather than an api with a well defined, stable and tested semantic
you going to get problems.

Remember last year when the Portal team complained that Hibernate's
"Transaction Demarcation" integration with JBoss was broken?

It was and it always was, even when it appeared to work. 
It was never tested!

Everybody "passed the buck" saying "it's not my problem",
except Steve Ebersole who fixed it. :-)

The real answer is, if you are using something that
isn't tested for regressions its almost certainly going
to fail at some point due to Murphy's law.

Caveat Emptor - buyer beware. :-)
-- 
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Adrian Brock
Chief Scientist
JBoss, a division of Red Hat
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