Add rewrite support

[Pankraz76]

See JENKINS-XXXXX.

Testing done

Proposed changelog entries

• human-readable text

Proposed changelog category

/label

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N/A

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Desired reviewers

@mention

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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:

• Apache Kafka’s integration
• Spotless’s implementation

Proposal

1. Add support for errorprone.refasterrules-based rewrites
2. Implement with opt-in adoption (no breaking changes)
3. Include suppression mechanisms for API constraints

Discussion Points

• Need consensus on:
  • Scope of auto-fixes
  • Preferred suppression strategy
  • Integration approach

Next Steps

I’m happy to:

• Prepare a PoC demonstrating the value
• Collaborate on implementation strategy
• Address any concerns about compatibility

relates to:

• implement IDE agnostic configuration with editorconfig.org checkstyle/checkstyle#16543
• Add rewrite support for errorprone.refasterrules checkstyle/checkstyle#17487

[github-actions]

Missing required label for changelog. Requires at least 1 of: bug, developer, dependencies, internal, localization, major-bug, major-rfe, rfe, regression-fix, removed, skip-changelog. Found: .

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