Dead Code Auditor (L3 Worker)

Specialized worker auditing unused and unreachable code.

Purpose & Scope

Worker in ln-620 coordinator pipeline
Audit dead code (Category 9: Low Priority)
Find unused imports, variables, functions, commented-out code
Calculate compliance score (X/10)

Inputs (from Coordinator)

Receives

contextStore

with tech stack, codebase root.

Workflow

Parse context
Run dead code detection (linters, grep)
Collect findings
Calculate score
Return JSON

Audit Rules

1. Unreachable Code

Detection:

Linter rules:
```
no-unreachable
```
(ESLint)
Check code after
```
return
```
,
```
throw
```
,
```
break
```

Severity: MEDIUM

2. Unused Imports/Variables/Functions

Detection:

ESLint:
```
no-unused-vars
```
TypeScript:
```
noUnusedLocals
```
,
```
noUnusedParameters
```
Python:
```
flake8
```
with
```
F401
```
,
```
F841
```

Severity:

MEDIUM: Unused functions (dead weight)
LOW: Unused imports (cleanup needed)

3. Commented-Out Code

Detection:

Grep for
```
//.*{
```
or
```
/*.*function
```
patterns
Large comment blocks (>10 lines) with code syntax

Severity: LOW

Recommendation: Delete (git preserves history)

4. Legacy Code & Backward Compatibility

What: Backward compatibility shims, deprecated patterns, old code that should be removed

Detection:

Renamed variables/functions with old aliases:
- Pattern:
```
const oldName = newName
```
  or
```
export { newModule as oldModule }
```
- Pattern:
```
function oldFunc() { return newFunc(); }
```
  (wrapper for backward compatibility)
Deprecated exports/re-exports:
- Grep for
```
// DEPRECATED
```
  ,
```
@deprecated
```
  JSDoc tags
- Pattern:
```
export.*as.*old.*
```
  or
```
export.*legacy.*
```

Conditional code for old versions:

Pattern:

if.*legacy.*

if.*old.*version.*

isOldVersion ? oldFunc() : newFunc()

Migration shims and adapters:
- Pattern:
```
migrate.*
```
  ,
```
Legacy.*Adapter
```
  ,
```
.*Shim
```
  ,
```
.*Compat
```

Comment markers:

Grep for

// backward compatibility

// legacy support

// TODO: remove in v

Grep for

// old implementation

// deprecated

// kept for backward

Severity:

HIGH: Backward compatibility shims in critical paths (auth, payment, core features)
MEDIUM: Deprecated exports still in use, migration code from >6 months ago
LOW: Recent migration code (<3 months), planned deprecation with clear removal timeline

Recommendation:

Remove backward compatibility shims - breaking changes are acceptable when properly versioned
Delete old implementations - keep only the correct/new version
Remove deprecated exports - update consumers to use new API
Delete migration code after grace period (3-6 months)
Clean legacy support comments - git history preserves old implementations

Effort:

S: Remove simple aliases, delete deprecated exports
M: Refactor code using old APIs to new APIs
L: Remove complex backward compatibility layer affecting multiple modules

Scoring Algorithm

See

shared/references/audit_scoring.md

for unified formula and score interpretation.

Output Format

json

{
  "category": "Dead Code",
  "score": 6,
  "total_issues": 12,
  "critical": 0,
  "high": 2,
  "medium": 3,
  "low": 7,
  "checks": [
    {"id": "unreachable_code", "name": "Unreachable Code", "status": "passed", "details": "No unreachable code detected"},
    {"id": "unused_exports", "name": "Unused Exports", "status": "failed", "details": "3 unused functions found"},
    {"id": "commented_code", "name": "Commented Code", "status": "warning", "details": "7 blocks of commented code"},
    {"id": "legacy_shims", "name": "Legacy Shims", "status": "failed", "details": "2 backward compatibility shims"}
  ],
  "findings": [
    {
      "severity": "MEDIUM",
      "location": "src/utils/helpers.ts:45",
      "issue": "Function 'formatDate' is never used",
      "principle": "Code Maintainability / Clean Code",
      "recommendation": "Remove unused function or export if needed elsewhere",
      "effort": "S"
    },
    {
      "severity": "HIGH",
      "location": "src/api/v1/auth.ts:12-15",
      "issue": "Backward compatibility shim for old password validation (6+ months old)",
      "principle": "No Legacy Code / Clean Architecture",
      "recommendation": "Remove old password validation, keep only new implementation. Update API version if breaking.",
      "effort": "M"
    }
  ]
}

Reference Files

Audit scoring formula:
```
shared/references/audit_scoring.md
```

Audit output schema:

shared/references/audit_output_schema.md

Version: 3.0.0 Last Updated: 2025-12-23

ln-626-dead-code-auditor

NPX Install

Tags

SKILL.md Content

Dead Code Auditor (L3 Worker)

Purpose & Scope

Inputs (from Coordinator)

Workflow

Audit Rules

1. Unreachable Code

2. Unused Imports/Variables/Functions

3. Commented-Out Code

4. Legacy Code & Backward Compatibility

Scoring Algorithm

Output Format

Reference Files