TCK: MissingValueOnObserverMethodInjectionTest fails for a different reason

[mkouba]

Describe the bug
org.eclipse.microprofile.config.tck.broken.MissingValueOnObserverMethodInjectionTest asserts a DeploymentException. However, since the ConfigObserver bean is @ApplicationScoped (must be proxyable) and final (unproxybale type) the deployment fails but for a different reason:
https://github.com/eclipse/microprofile-config/blob/master/tck/src/main/java/org/eclipse/microprofile/config/tck/broken/ConfigObserver.java#L40

[mkouba]

Actually, it seems that the bean class is final and declares private no-args constructor, ie. unproxyable, but the observer method is static. That's very confusing. The truth is that a CDI container should only validate bean types used for injection points but what's the point of @ApplicationScoped?

[dmlloyd]

@ljnelson ?

[ljnelson]

Happy to make any changes needed. What's the recommendation? The original PR is here: #423.

[mkouba]

Ideally, a test like this should rely on minimum features and if possible avoid "unusual" features. In this particular case, pls remove the final flag from the ConfigObserver class and use an ordinary observer method instead of the static one.