📋 Introduction

AACR-Bench is the industry’s first multilingual, repository-level context-aware code review evaluation dataset, designed to assess the performance of large language models in automated code review tasks. The dataset comprises 200 real Pull Requests from 50 active open-source projects, covering 10 mainstream programming languages. Each instance includes not only code changes but also preserves complete repository context, authentically reproducing the entire code review process. Through human-LLM collaborative review combined with multi-round expert annotation, we ensure high quality and comprehensiveness of the data.

✨ Core Features

🌍 Multi-language Coverage

Covers 10 mainstream programming languages used in projects:

• System-level languages: C++, Rust, Go
• Enterprise languages: Java, C#, TypeScript
• Scripting languages: Python, JavaScript, Ruby, PHP

📁 Repository-level Context

• Preserves complete project structure
• Supports cross-file references and inter-module interaction analysis
• Includes PR metadata (description, title, comments, etc.)

🤖 Human Expert + LLM Enhanced Annotation

Professional Annotation Team

• 80+ senior software engineers with 2+ years of experience
• Covers frontend, backend, architecture, and other domains
• Three rounds of cross-validation

LLM Intelligent Enhancement

• Systematic issue discovery
• Comprehensive defect identification
• Improvement suggestion generation

Quality Assurance Process: GitHub human comments → LLM enhancement → Expert multi-round cross-annotation → Consistency validation

🎯 Evaluation Capabilities and Applications

AACR-Bench provides systematic evaluation capabilities across four core dimensions, supporting diverse research and application scenarios:

Evaluation Dimension System

1️⃣ Multi-language Evaluation (10 Languages)	2️⃣ Positioning Accuracy Evaluation (Line-level)
• Cross-language performance comparison: Identify model strengths and weaknesses across languages • Language-specific optimization: Improve model capabilities for specific languages • Generalization assessment: Test model’s language transfer effectiveness	• Precise positioning: Assess single-line/multi-line issue location accuracy • Cross-file tracking: Test cross-file reference identification capability • Context boundaries: Verify issue scope judgment accuracy
3️⃣ Issue Classification Evaluation (4 Categories)	4️⃣ Context Understanding Evaluation (3 Levels)
• Classification accuracy: Assess issue type identification capability • Severity assessment: Test issue priority judgment • Specialized capabilities: Analyze detection rates for specific issue types	• Diff-level understanding: Basic code change analysis • File-level understanding: Complete file logic comprehension • Repo-level understanding: Project-wide dependency analysis

Typical Application Scenarios

Model Development

• Performance benchmarking: Evaluate new models’ code review capabilities using unified standards
• Weakness analysis: Discover model shortcomings through fine-grained metrics (e.g., low recall in certain languages)
• Iterative optimization validation: Quantify improvement effects, guide continuous model optimization

Academic Research

• Comparative studies: Fair comparison of different model architectures/training methods
• Ablation experiments: Analyze the impact of different context levels on review quality
• New method validation: Provide standardized evaluation environment for innovative algorithms

Engineering Practice

• Model selection: Help teams choose review models suitable for project characteristics
• Pre-deployment validation: Ensure model reliability in production environments
• Continuous monitoring: Track model performance changes in actual use

🚀 Quick Start

git clone https://github.com/alibaba/aacr-bench.git
cd aacr-bench

The evaluation framework is in the evaluation/ directory, which provides a unified pipeline: data loading → review execution → evaluation. It supports three reviewers: OpenCodeReview (OCR), Claude Code, and Codex. See evaluation/README.md for detailed setup and usage.

📈 Data Overview

Dataset Scale

Classification Statistics

Language Distribution

Data Format

{
  "type": "array",
  "item": {
    "change_line_count": {"type": "integer", "description": "Number of changed lines"},
    "project_main_language": {"type": "string", "description": "Project main language"},
    "source_commit": {"type": "string", "description": "Source commit"},
    "target_commit": {"type": "string", "description": "Target commit"},
    "githubPrUrl": {"type": "string", "description": "GitHub PR URL"},
    "comments": {
      "is_ai_comment": {"type": "boolean", "description": "Whether it's an AI comment"},
      "note": {"type": "string", "description": "Comment content"},
      "path": {"type": "string", "description": "File path"},
      "side": {"type": "string", "description": "Comment anchor position"},
      "source_model": {"type": "string", "description": "Source model"},
      "from_line": {"type": "integer", "description": "Start line number"},
      "to_line": {"type": "integer", "description": "End line number"},
      "category": {"type": "string", "description": "Issue category: Security/Defect/Maintainability/Performance"},
      "context": {"type": "string", "description": "Comment scope: diff/file/repo level"}
    }
  }
}

📏 Evaluation Metrics

We employ a multidimensional metric system to comprehensively evaluate code review model performance. For complete metric definitions, calculation methods, and language-specific statistics, please refer to metrics.md.

Core Metrics

Metric	Description	Formula
Precision	Proportion of valid comments generated	Valid matches / Total generated
Recall	Ability to discover annotated issues	Valid matches / Dataset valid count
Line Precision	Ability to precisely locate code lines	Line matches / Total generated
Noise Rate	Proportion of invalid or incorrect comments	Unmatched / Total generated

🤝 Contributing

We welcome community contributions! If you want to contribute to AACR-Bench, please follow these steps:

1. Fork this repository
2. Create feature branch (git checkout -b feat/add-new-prs)
3. Commit changes (git commit -m 'feat: add new PRs')
4. Push to branch (git push origin feat/add-new-prs)
5. Create Pull Request

For detailed contribution guidelines, please refer to CONTRIBUTING.md

👥 Authors and Maintainers

Name	GitHub	Domain	Responsibilities
Zhengfeng Li	@lizhengfeng	Project Lead	Overall architecture design, technical direction
Boge Wang	@wangboge	Technical Consultant	Technical Solution Review, technical Guidance
Lei Zhang	@zhanglei	Data Architecture	Evaluation framework, metric system, performance optimization
Yongda Yu	@yuyongda	Evaluation System	Data schema design, evaluation protocol, quality standards
Xinxin Guo	@guoxinxin	Annotation Platform	Annotation system development, workflow design, quality assurance
Minghui Yu	@yuminghui	AI Enhancement	LLM annotation pipeline, model selection, prompt optimization
Zhengqi Zhuang	@zhuangzhengqi	Engineering	CI/CD pipeline, automated testing, deployment scripts

📄 License

This project is licensed under the Apache License 2.0. For details, please see the LICENSE file.

📚 Citation

If you use AACR-Bench in your research, please cite our paper:

@misc{zhang2026aacrbenchevaluatingautomaticcode,
      title={AACR-Bench: Evaluating Automatic Code Review with Holistic Repository-Level Context}, 
      author={Lei Zhang and Yongda Yu and Minghui Yu and Xinxin Guo and Zhengqi Zhuang and Guoping Rong and Dong Shao and Haifeng Shen and Hongyu Kuang and Zhengfeng Li and Boge Wang and Guoan Zhang and Bangyu Xiang and Xiaobin Xu},
      year={2026},
      eprint={2601.19494},
      archivePrefix={arXiv},
      primaryClass={cs.SE},
      url={https://arxiv.org/abs/2601.19494}, 
}

🗺️ Roadmap

• v1.0 (2026.01): Initial release - 200 PRs, 10 languages

🌟 Acknowledgments

• Thanks to all contributors who participated in data annotation, especially core contributors who completed 15+ valid annotations. Full list in CONTRIBUTORS.md.
• Thanks to open-source project maintainers for providing original PR data.