MINOR: extract TestSslUtils to new test-common-base

[soarez]

This change moves TestSslUtils, TestUtils and accessory classes from the
test classpath in clients to a new module: test-common-base,
allowing other modules to use these classes for testing without having
to include all of the test classpath for clients.

The package name for these classes changed, from org.apache.kafka.test
to org.apache.kafka.base.test.

The move from a test classpath to a main classpath triggered some issues
with spotbugs which were addressed. A couple of reflection utilities
required a new exception, and were moved to their own class to isolate
it.

For some modules it was possible to replace the dependency on
project(':clients').sourceSets.test.output with
project(:test-common:test-common-base), but the others still have to
keep both dependencies for now.

For further details on the context and purpose of this change, check
this thread:
#20376 (comment)

Reviewers: Ken Huang s7133700@gmail.com, Chia-Ping Tsai
chia7712@gmail.com

[m1a2st]

Thanks to @soarez for this patch. Could we add some documentation for this new module?

[soarez]

@m1a2st where would be a good place for docs? We can add a README.md, but I haven't found one for other modules. Currently there's only a few lines of comment in build.gradle, like others, to explain the purpose of this module.

[m1a2st]

I think we can place the README.md in the root of the module, similar to https://github.com/apache/kafka/tree/trunk/trogdor

I’m wondering if we could add more comprehensive documentation to clarify what this module is intended to contain. There are already many different TestUtils in all module, and without clear guidelines, it’s easy for the utilities in to test-common-base grow too large.

For now, a comment in build.gradle might be sufficient.

SSL utilities, wait functions, file-related operations

Should JaasUtils also be moved to this new module?

[chia7712]

typo? nase

[soarez]

yes, good catch. removed this rule

[chia7712]

In order to align with other modules, maybe we should use org.apache.kafka.common.test.base instead

[soarez]

Agreed. I renamed the package

[chia7712]

Have you considered using TestReflectionUtils?

[soarez]

I didn't, but I like it. The 'Test' prefix makes it clear this is a test utility. Renamed

[soarez]

Should JaasUtils also be moved to this new module?

@m1a2st I can't see a reason why not. These are the implications:

• test-common-runtime would have to depend on test-common-base.
• JaasModule would have to move too.
• Both classes would need a rewrite to avoid the use of record due to the language level requirement for test-common-base.

If we all think the above are acceptable changes, I'm happy to include this in a subsequent patch, as this one is already quite large and changes a lot of import statements, making it easy to run into merge conflicts.

[m1a2st]

Thanks @soarez, I think we can address these in a follow-up patch.

[chia7712]

This reference causes AppInfoParserTest to fail, as it makes the test scope depend on the JAR rather than class files. While not a serious issue, it does prompt me to rethink the approach of this PR. Perhaps we should consider using fixtures that allow us to keep the same package while maintaining isolation. WDYT?

[chia7712]

I noticed that you are using implementation project(':clients').sourceSets.main.output instead of fixtures. Would you mind sharing reasoning behind this?