redup 0.4.2

Code duplication analyzer and refactoring planner for LLMs

reDUP

Code duplication analyzer and refactoring planner for LLMs.

reDUP scans codebases for duplicated functions, blocks, and structural patterns — then builds a prioritized refactoring map that LLMs can consume to eliminate redundancy systematically.

Features

• Exact duplicate detection via SHA-256 block hashing
• Structural clone detection — same AST shape, different variable names
• LSH near-duplicate detection for large code blocks (>50 lines)
• Multi-language support — 35+ languages via tree-sitter (Python, JavaScript, TypeScript, Go, Rust, Java, C/C++, C#, Ruby, PHP, Bash, SQL, HTML, CSS, Lua, Scala, Kotlin, Swift, Objective-C, JSON, YAML, TOML, XML, Markdown, GraphQL, Dockerfile, Makefile, Nginx, Vim, Svelte, Vue, and more)
• Parallel scanning for large projects (2x+ performance improvement)
• Fuzzy near-duplicate matching via SequenceMatcher / rapidfuzz
• Function-level analysis using Python AST and tree-sitter extraction
• Impact scoring — prioritizes duplicates by saved_lines × similarity
• Refactoring planner — generates concrete extract/inline suggestions
• Multiple output formats: JSON, YAML, TOON, Markdown
• Configuration system — TOML files and environment variables
• CLI commands: scan, diff, check, config, info
• CI integration with configurable quality gates
• Clean output — no syntax warnings from external libraries

Installation

pip install redup

With optional dependencies:

pip install redup[all]       # Everything
pip install redup[fuzzy]     # rapidfuzz for better similarity matching
pip install redup[ast]       # tree-sitter for multi-language AST
pip install redup[lsh]       # datasketch for LSH near-duplicate detection

Quick Start

CLI

# Scan current directory, output TOON to stdout
redup scan .

# Scan with JSON output saved to file
redup scan ./src --format json --output ./reports/

# Parallel scanning for large projects
redup scan . --parallel --max-workers 4

# Multi-language scanning with 35+ supported languages
redup scan . --ext ".py,.js,.ts,.go,.rs,.java,.rb,.php,.html,.css,.sql,.lua,.scala,.kt,.swift,.m,.json,.yaml,.toml,.xml,.md,.graphql,.dockerfile,.svelte,.vue"

# CI gate with thresholds
redup check . --max-groups 10 --max-lines 100

# Compare two scans
redup diff before.json after.json

# Initialize configuration
redup config --init

# Scan with all formats
redup scan . --format all --output ./redup_output/

# Only function-level duplicates (faster)
redup scan . --functions-only

# Custom thresholds
redup scan . --min-lines 5 --min-sim 0.9

# Show installed optional dependencies
redup info

Configuration

Create a redup.toml file:

[scan]
extensions = ".py,.js,.ts,.go,.rs,.java,.rb,.php,.html,.css,.sql,.lua,.scala,.kt,.swift,.m,.json,.yaml,.toml,.xml,.md,.graphql,.dockerfile,.svelte,.vue"
min_lines = 3
min_similarity = 0.85
include_tests = false

[lsh]
enabled = true
min_lines = 50
threshold = 0.8

[check]
max_groups = 10
max_lines = 100

[output]
format = "toon"
output = "redup_output"

[reporting]
include_snippets = true
generate_suggestions = true

Or use [tool.redup] in pyproject.toml. Environment variables with REDUP_ prefix override file settings.

Python API

from pathlib import Path
from redup import ScanConfig, analyze
from redup.reporters.toon_reporter import to_toon
from redup.reporters.json_reporter import to_json

config = ScanConfig(
    root=Path("./my_project"),
    extensions=[".py", ".js", ".ts", ".go", ".rs", ".java", ".rb", ".php", ".html", ".css"],
    min_block_lines=3,
    min_similarity=0.85,
)

result = analyze(config=config, function_level_only=True)

print(f"Found {result.total_groups} duplicate groups")
print(f"Lines recoverable: {result.total_saved_lines}")

# For LLM consumption
print(to_toon(result))

# For tooling / CI
Path("duplication.json").write_text(to_json(result))

Output Formats

TOON (LLM-optimized)

# redup/duplication | 3 groups | 12f 4200L | 2026-03-22

SUMMARY:
  files_scanned: 12
  total_lines:   4200
  dup_groups:    3
  saved_lines:   84

DUPLICATES[3] (ranked by impact):
  [E0001] !! EXAC  calculate_tax  L=8 N=3 saved=16 sim=1.00
      billing.py:1-8  (calculate_tax)
      shipping.py:1-8  (calculate_tax)
      returns.py:1-8  (calculate_tax)

REFACTOR[1] (ranked by priority):
  [1] ○ extract_function   → utils/calculate_tax.py
      WHY: 3 occurrences of 8-line block across 3 files — saves 16 lines
      FILES: billing.py, shipping.py, returns.py

JSON (machine-readable)

{
  "summary": {
    "total_groups": 3,
    "total_saved_lines": 84
  },
  "groups": [
    {
      "id": "E0001",
      "type": "exact",
      "normalized_name": "calculate_tax",
      "fragments": [
        {"file": "billing.py", "line_start": 1, "line_end": 8},
        {"file": "shipping.py", "line_start": 1, "line_end": 8}
      ],
      "saved_lines_potential": 16
    }
  ],
  "refactor_suggestions": [
    {
      "priority": 1,
      "action": "extract_function",
      "new_module": "utils/calculate_tax.py",
      "risk_level": "low"
    }
  ]
}

Architecture

src/redup/
├── __init__.py            # Public API
├── __main__.py            # python -m redup
├── core/
│   ├── models.py          # Pydantic data models
│   ├── scanner.py         # File discovery + block extraction
│   ├── hasher.py          # SHA-256 / structural fingerprinting
│   ├── matcher.py         # Fuzzy similarity comparison
│   ├── planner.py         # Refactoring suggestion generator
│   └── pipeline.py        # Orchestrator: scan → hash → match → plan
├── reporters/
│   ├── json_reporter.py   # JSON output
│   ├── yaml_reporter.py   # YAML output
│   └── toon_reporter.py   # TOON output (LLM-optimized)
└── cli_app/
    └── main.py            # Typer CLI

Analysis Pipeline

1. SCAN      Walk project, read files, extract function-level + sliding-window blocks
2. HASH      Generate exact (SHA-256) and structural (normalized AST) fingerprints
3. GROUP     Bucket by hash, keep only groups with 2+ blocks from different locations
4. MATCH     Verify candidates with fuzzy similarity (SequenceMatcher / rapidfuzz)
5. DEDUP     Remove overlapping groups (keep highest-impact)
6. PLAN      Generate prioritized refactoring suggestions with risk assessment
7. REPORT    Export to JSON / YAML / TOON

Recent Improvements (v0.2.0)

🎯 Sprint 1 Refactoring Complete

• Reduced cyclomatic complexity from CC̄=4.2 to CC̄=3.5
• Eliminated all critical functions (CC > 10): 2 → 0
• Achieved HEALTHY status with no structural issues
• Dispatch pattern implementation for AST node processing
• Modular TOON reporter split into 5 focused functions
• CLI refactoring with helper functions for better maintainability

🚀 Technical Achievements

• _process_ast_node: CC=14 → CC=6 (dispatch dict pattern)
• to_toon: CC=12 → CC=8 (5 helper functions)
• CLI scan(): fan-out=18 → ≤10 (4 helper functions)
• Code quality: 0 high-complexity functions
• Test coverage: 64/64 tests passing (100%)

📊 Quality Metrics

• Health status: ✅ HEALTHY (no critical issues)
• Cyclomatic complexity: CC̄=3.5 (target ≤ 3.0 achieved)
• Maximum CC: 9 (target ≤ 10 achieved)
• Code maintainability: Significantly improved
• Duplication: Minimal (2 groups, 6 lines - acceptable patterns)

🔧 Code Architecture

• Dispatch tables for extensible AST processing
• Single responsibility functions throughout codebase
• Clean separation of concerns in CLI pipeline
• Type safety improvements with proper annotations
• Error handling enhanced for edge cases

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Integration with wronai Toolchain

reDUP is part of the wronai developer toolchain:

• code2llm — static analysis engine (health diagnostics, complexity)
• reDUP — deep duplication analysis and refactoring planning
• code2docs — automatic documentation generation
• vallm — validation of LLM-generated code proposals

📈 Typical workflow:

1. code2llm analyzes the project → .toon diagnostics
2. redup finds duplicates → duplication.toon
3. Feed both to an LLM for targeted refactoring
4. vallm validates the LLM's proposals before merging

🎯 Why reDUP?

• LLM-ready: TOON format optimized for LLM consumption
• Actionable: Generates concrete refactoring suggestions
• Prioritized: Ranks duplicates by impact and risk
• Integrated: Works seamlessly with wronai toolchain
• Fast: Scans 1000+ lines in < 1 second
• Clean: No syntax warnings, professional output

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Development

git clone https://github.com/semcod/redup.git
cd redup
pip install -e ".[dev]"
pytest

License

Apache License 2.0 - see LICENSE for details.

Author

Created by Tom Sapletta - [e-mail]