[java] Fix #4770: UnusedFormalParameter should ignore public constructor as same as method

[UncleOwen]

Describe the PR

Treat public constructors the exact same way as public methods.

Related issues

• Fix [java] UnusedFormalParameter should ignore public constructor as same as method #4770

Ready?

I could use some help here. The problem is this line. If it's present, dogfood tells me to remove it. If it's not present, verify tells me to add it. How do I get around this?

• Added unit tests for fixed bug/feature
• Passing all unit tests
• Complete build ./mvnw clean verify passes (checked automatically by github actions)
• Added (in-code) documentation (if needed)

[zbynek]

If it's present, dogfood tells me to remove it. If it's not present, verify tells me to add it. How do I get around this?

Instead of suppressing the warning, why not just remove the formal parameter? The constructor is called from one place only.

[UncleOwen]

Because the code says

        // topNode is unused, but we'll need it if we want to discount lambdas
        // if we add it later, we break binary compatibility

[UncleOwen]

On the other hand, the file is in a package called internal. Does that mean, breaking binary compatibility isn't a concern?

[pmd-actions-helper]

Documentation Preview

Compared to main:
This changeset changes 0 violations,
introduces 1 new violations, 0 new errors and 0 new configuration errors,
removes 602 violations, 0 errors and 0 configuration errors.

Regression Tester Report

(comment created at 2025-08-19 11:27:25+00:00 for ad73e08)

[UncleOwen]

Found the answer myself: If the variable name begins with ignore or unused, there is no violation.

[adangel]

On the other hand, the file is in a package called internal. Does that mean, breaking binary compatibility isn't a concern?

Yes, that's what internal means - we could basically remove the parameter. Not sure, what this comment about binary compatibility is about here.

The API compatibility is described here: https://docs.pmd-code.org/latest/pmd_projectdocs_decisions_adr_3.html