Add `rewrite` support for `errorprone.refasterrules`

[Pankraz76]

Description

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

[DaveCTurner]

Thanks for your interest @Pankraz76. Adopting a new static analysis toolset imposes nontrivial work, and we're not seeing sufficient benefits to go down this path right now. We continue to evaluate the situation, and if we start to see compelling reasons to adopt Google's Error Prone in future then we'll reconsider.

[Pankraz76]

static analysis toolset imposes nontrivial work
Yes and no. It's effectively free since it auto-fixes itself—just like Spotless—as long as CI handles it.

The analysis only creates extra work if the code is corrupt. For a project that emphasizes quality, it's surprising PMD's ErrorProne ruleset isn't configured yet. Those rules would catch the same issues this auto-fix addresses—worth considering.

I'll implement the Spotless fix because I value software quality. This is an opportunity you could benefit from.

As a Spotless/PMD/Checkstyle contributor, I recognize this misconfiguration. Most projects fail to properly adopt "convention over configuration"—an important principle.

Having rolled out this UX improvement successfully 10+ times (always well-received), this is the first rejection. Nearly all projects welcome enhanced look and feel—especially their logo.

• [chore] Add project icon for IntelliJ IDEA #131427