Add `rewrite` support for `errorprone.refasterrules`

[Pankraz76]

Add rewrite support for errorprone.refasterrules

I’d like to propose integrating Google’s Error Prone and its Picnic extension (demonstrated in Automating Away Bugs with Error Prone | PlatformCon 2023) to enable automated bug fixes via rewrite rules. This would complement Checkstyle’s static analysis capabilities by addressing semantic bugs rather than stylistic issues.

Motivation

Error Prone’s refaster/rewrite rules can automatically:

• Fix common bug patterns (e.g., String.equals() misuse)
• Modernize code (e.g., JDK migration helpers)
• Enforce best practices (e.g., null-check improvements)

Real-world adoptions show tangible benefits:

• Issue #17487: Introduce Rewrite covering S1144: Unused "private" methods should be removed checkstyle/checkstyle#17545
• Fix #5953: [java] PoC: Add rewrite support for errorprone.refasterrules pmd/pmd#5956
• Introduce Rewrite & PMD covering S1144: Unused "private" methods should be removed opensearch-project/OpenSearch#18791
• PoC: Add rewrite support for errorprone.refasterrules diffplug/spotless#2576
• PoC: Add rewrite support for errorprone.refasterrules apache/kafka#20219

This might be something to gain feedback on in boot, to start strings up, see the alignment in an ease, following the same direction and convention.

Thanks for considering.

[philwebb]

Thanks for the suggestion. Errorprone is something we're planning to investigate at some point, but currently we don't have the bandwidth to take this on. It's something we might get to after 4.0.x has been released.

[Pankraz76]

Hi, thanks for the feedback, yes thats totally reasonable.

Just to let you know that its actually just an effort of minutes, considering its only 1 LOC to target than dedicated recipes like removeunusedprivatemethods. The adoption for the dev´s is also kind of a no brainer, as its always the same command to fix any kind of bug/issue/flaw.

Lets me know if you want some PoC, thanks for considering.

[Pankraz76]

Having moved forward in several other major projects, it seems ready and easy to integrate, keeping the focus tight.

• Issue #17487: Add StreamRulesRecipes checkstyle/checkstyle#17782
• Apply StreamRulesRecipes apache/maven#11159
• [openrewrite] add SanityCheck featuring CommonStaticAnalysis diffplug/spotless#2651
• [openrewrite] add SanityCheck featuring tech.picnic.errorprone.refasterrules junit-team/junit-framework#5003