ln-626-dead-code-auditor

SKILL.md

Paths: File paths (references/, ../ln-*) are relative to this skill directory.

Dead Code Auditor (L3 Worker)

Type: L3 Worker

Specialized worker auditing unused and unreachable code.

Purpose & Scope

Audit dead code (Category 9: Low Priority)

Find unused imports, variables, functions, commented-out code

Calculate compliance score (X/10)

Inputs

MANDATORY READ: Load references/audit_worker_core_contract.md.
MANDATORY READ: Load references/mcp_tool_preferences.md and references/mcp_integration_patterns.md
Receives contextStore with tech stack, codebase root, output_dir.

Use hex-graph first when export liveness or workspace hotspots materially improve the audit. Use hex-line first for local code reads when available. If MCP is unavailable, unsupported, or not indexed, continue with built-in Read/Grep/Glob/Bash and state the fallback in the report.

Workflow

MANDATORY READ: Load references/two_layer_detection.md for detection methodology.

Parse context + output_dir

Run dead code detection (Layer 1: linters, grep)

Graph-capable projects: For JavaScript, TypeScript/TSX, Python, C#, and PHP, use index_project then bounded audit_workspace(verbosity="minimal", limit=5) as primary detection for unused exports when graph indexing is available. Raise limit only for deliberate drill-down.

Keep grep/linter fallback for unsupported languages, graph-unavailable runs, and checks outside export liveness.

Analyze context per candidate (Layer 2):

Unused functions: used via dynamic import/reflection? Exported in public API? Used in other packages (monorepo)?

Commented code: TODO with context or algorithm explanation -> FP. Truly dead code block -> confirmed

Legacy shims: read git blame -- age? Is there an issue/PR tracking removal?

Collect confirmed findings

Calculate score

Write Report: Build full markdown report in memory per references/templates/audit_worker_report_template.md, write to {output_dir}/ln-626--global.md in single Write call

Return Summary: Return minimal summary to coordinator

Audit Rules

MANDATORY READ: Load references/clean_code_checklist.md for universal dead code patterns and severity definitions.

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, unsupported 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)

Unsupported exports/re-exports:

Grep for // DEPRECATED, @obsolete JSDoc tags

Pattern: export.*as.*old.* or export.*legacy.*

Conditional code for old versions:

Pattern: if.*legacy.* or if.*old.*version.* or 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, // unsupported, // kept for backward

Severity:

HIGH: Backward compatibility shims in critical paths (auth, payment, core features)

MEDIUM: Unsupported 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 unsupported 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 unsupported exports

M: Refactor code using old APIs to new APIs

L: Remove complex backward compatibility layer affecting multiple modules

Scoring Algorithm

MANDATORY READ: Load references/audit_worker_core_contract.md and references/audit_scoring.md.

Output Format

MANDATORY READ: Load references/audit_worker_core_contract.md and references/templates/audit_worker_report_template.md.

Write JSON summary per references/audit_summary_contract.md. In managed mode the caller passes both runId and summaryArtifactPath; in standalone mode the worker generates its own run-scoped artifact path per shared contract.

Write report to {output_dir}/ln-626--global.md with category: "Dead Code" and checks: unreachable_code, unused_exports, commented_code, legacy_shims.

Return summary per references/audit_summary_contract.md.

When summaryArtifactPath is absent, write the standalone runtime summary under .hex-skills/runtime-artifacts/runs/{run_id}/evaluation-worker/{worker}--{identifier}.json and optionally echo the same summary in structured output.

Report written: .hex-skills/runtime-artifacts/runs/{run_id}/audit-report/ln-626--global.md
Score: X.X/10 | Issues: N (C:N H:N M:N L:N)

Reference Files

Clean code checklist: references/clean_code_checklist.md

Audit output schema: references/audit_output_schema.md

Critical Rules

MANDATORY READ: Load references/audit_worker_core_contract.md.

Do not auto-fix: Report only, never delete code

Age-aware severity: Legacy shims >6 months = MEDIUM, <3 months = LOW

Effort realism: S = <1h, M = 1-4h, L = >4h

Exclusions: Skip generated code, vendor, migrations, test fixtures

Git-aware: Recommend deletion confidently -- git history preserves old code

Definition of Done

MANDATORY READ: Load references/audit_worker_core_contract.md.

 contextStore parsed (including output_dir)

 All 4 checks completed (unreachable code, unused imports/vars/functions, commented-out code, legacy shims)

 Clean code checklist loaded from references/clean_code_checklist.md

 Findings collected with severity, location, effort, recommendation

 Score calculated per references/audit_scoring.md

 Report written to {output_dir}/ln-626--global.md (atomic single Write call)

 Summary written per contract

Version: 3.0.0
Last Updated: 2025-12-23