dedupe-scan

name	dedupe-scan
description	Find and report duplicated code patterns. Read-only - does not fix.

/dedupe-scan [path]

Read-only scan for duplicated code patterns. Reports findings without making changes.

No arguments? Describe this skill and stop. Do not execute.

Process

1. Search for common duplication patterns
2. Analyze each finding for true duplication
3. Report with consolidation recommendations

Also Detect: AI-Generated Antipatterns

In addition to duplicates, flag these signs of AI-generated code:

Antipattern	How to Detect
Over-abstraction	Factory/Builder/Wrapper classes used only once
Defensive paranoia	Null checks on values that can never be null
Speculative features	Config options with only one value ever used
Wrapper classes	Classes that just delegate to another class
Enterprise patterns	AbstractFactory, *Builder, *Manager in simple code

Report these in a separate "AI Antipatterns Detected" section.

---

Patterns to Detect

Search for these function/pattern names appearing in multiple files:

PATTERN                         SEARCH
──────────────────────────────────────────────────────────────
Directory operations            function copy.*Directory
                                function.*Recursive
Hashing                         function hash
                                createHash
Git operations                  execSync.*git
                                getGitCommit
                                getGitRemote
File operations                 fs.readFileSync (repeated)
                                fs.writeFileSync (repeated)
                                fs.existsSync (repeated patterns)
Validation                      function validate
                                function is[A-Z].*\(
Path resolution                 path.join.*\.claude
                                homedir()
Error handling                  try.*catch (identical blocks)

Search Commands

Run these searches in parallel:

# Function definitions appearing in multiple files
grep -r "function copy" --include="*.ts" | grep -v test | grep -v node_modules

# Hash functions
grep -r "function hash" --include="*.ts" | grep -v test | grep -v node_modules

# Git exec calls
grep -r "execSync.*git" --include="*.ts" | grep -v test | grep -v node_modules

# Repeated utility patterns
grep -r "createHash" --include="*.ts" | grep -v test | grep -v node_modules

Analysis Criteria

A pattern is TRUE DUPLICATION if:

• Same logic in 2+ files
• Could be extracted to shared utility
• No semantic reason to keep separate

A pattern is FALSE POSITIVE if:

• Similar names but different logic
• Intentionally separate (different algorithms)
• Test files duplicating production code

REQUIRED Output Format

## Deduplication Report: [path]

DUPLICATIONS_FOUND: N

### 1. [Pattern Name]
FILES:
- [file1:line] - [brief description]
- [file2:line] - [brief description]

RECOMMENDATION: [Extract to utils/X.ts | Keep separate because Y]

### 2. [Pattern Name]
...

FALSE_POSITIVES_SKIPPED: N
- [pattern]: [reason kept separate]

CONSOLIDATION_PRIORITY:
1. [highest impact pattern]
2. [next pattern]
3. ...

DEDUPLICATION_COMPLETE

Example Output

## Deduplication Report: src/

DUPLICATIONS_FOUND: 3

### 1. copyDirectoryRecursive
FILES:
- src/canon/helpers.ts:114 - sync recursive copy
- src/workflow/index.ts:223 - sync recursive copy
- src/profiles/apply.ts:94 - async recursive copy

RECOMMENDATION: Extract to utils/fs.ts with sync and async variants

### 2. hashDirectory
FILES:
- src/canon/hash.ts:21 - hashSkillDirectory
- src/workflow/index.ts:191 - hashDirectory

RECOMMENDATION: Keep separate - different algorithms for different manifest formats

FALSE_POSITIVES_SKIPPED: 1
- validateProfile: Different validation logic per module

CONSOLIDATION_PRIORITY:
1. copyDirectoryRecursive (3 files, identical logic)
2. git operations (2 files, execSync vs file read)

DEDUPLICATION_COMPLETE

After Analysis

Report findings only. Use /deduplication to consolidate duplicates.

Comparison

Skill	Finds	Fixes
/dedupe-scan	✓	✗ (read-only)
/deduplication	✓	✓ (consolidates)