Fix reporting of @Ignored JUnit 3 test classes

[pshevche]

Overview

If JUnit3 test cases are annotated w/ @Ignore and run w/ JUnit Vintage engine, they will be reported twice: once as started and once as skipped.

This is caused by inconsistent checking for the annotation presence. DefensiveAllDefaultPossibilitiesBuilder will check for the annotation presence on the Java class to create an IgnoringRunnerDecorator (ref), while RunListenerAdapter will look for the annotation on the runner's Description to actually ignore the class (ref).

So, if the Java class is annotated w/ @Ignore, but the runner does no add it to the root Description, then the test class will be once reported as started by the RunListenerAdapter and once as skipped by IgnoringRunnerDecorator. And this is exactly the case for JUnit38ClassRunner which does not include class-level annotation in the runner's description (ref).

In this PR, I propose to explicilty add @Ignore annotation for the JUnit3 runner's description and warn creators of custom runners about the missing annotation. I open this PR as a draft proposal first to discuss the approach.

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I hereby agree to the terms of the JUnit Contributor License Agreement.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[marcphilipp]

@pshevche Thanks for the PR! I had some qualms about decorating Description so went a slight different route. Instead of looking for the annotation in IgnoringRunnerDecorator that's now done in RunListenerAdapter.

[pshevche]

@marcphilipp , looks good from my side, thank you for getting it over the finish line 👍