ln-624-code-quality-auditor

name	ln-624-code-quality-auditor
description	Code quality audit worker (L3). Checks cyclomatic complexity, deep nesting, long methods, god classes, method signature quality, O(n²) algorithms, N+1 queries, magic numbers/constants. Returns findings with severity, location, effort, recommendations.
allowed-tools	Read, Grep, Glob, Bash

Paths: File paths (shared/, references/, ../ln-*) are relative to skills repo root. If not found at CWD, locate this SKILL.md directory and go up one level for repo root.

Code Quality Auditor (L3 Worker)

Specialized worker auditing code complexity, method signatures, algorithms, and constants management.

Purpose & Scope

• Worker in ln-620 coordinator pipeline - invoked by ln-620-codebase-auditor
• Audit code quality (Categories 5+6+NEW: Medium Priority)
• Check complexity metrics, method signature quality, algorithmic efficiency, constants management
• Return structured findings with severity, location, effort, recommendations
• Calculate compliance score (X/10) for Code Quality category

Inputs (from Coordinator)

MANDATORY READ: Load shared/references/task_delegation_pattern.md#audit-coordinator--worker-contract for contextStore structure.

Receives contextStore with: tech_stack, best_practices, principles, codebase_root, output_dir.

Domain-aware: Supports domain_mode + current_domain (see audit_output_schema.md#domain-aware-worker-output).

Workflow

1. Parse context — extract fields, determine scan_path (domain-aware if specified), extract output_dir

2. Scan codebase for violations

   • All Grep/Glob patterns use scan_path (not codebase_root)
   • Example: Grep(pattern="if.*if.*if", path=scan_path) for nesting detection

3. Collect findings with severity, location, effort, recommendation

   • Tag each finding with domain: domain_name (if domain-aware)

4. Calculate score using penalty algorithm

5. Write Report: Build full markdown report in memory per shared/templates/audit_worker_report_template.md, write to {output_dir}/624-quality-{domain}.md (or 624-quality.md in global mode) in single Write call

6. Return Summary: Return minimal summary to coordinator (see Output Format)

Audit Rules (Priority: MEDIUM)

1. Cyclomatic Complexity

What: Too many decision points in single function (> 10)

Detection:

• Count if/else, switch/case, ternary, &&, ||, for, while
• Use tools: eslint-plugin-complexity, radon (Python), gocyclo (Go)

Severity:

• HIGH: Complexity > 20 (extremely hard to test)
• MEDIUM: Complexity 11-20 (refactor recommended)
• LOW: Complexity 8-10 (acceptable but monitor)

Recommendation: Split function, extract helper methods, use early returns

Effort: M-L (depends on complexity)

2. Deep Nesting (> 4 levels)

What: Nested if/for/while blocks too deep

Detection:

• Count indentation levels
• Pattern: if { if { if { if { if { ... } } } } }

Severity:

• HIGH: > 6 levels (unreadable)
• MEDIUM: 5-6 levels
• LOW: 4 levels

Recommendation: Extract functions, use guard clauses, invert conditions

Effort: M (refactor structure)

3. Long Methods (> 50 lines)

What: Functions too long, doing too much

Detection:

• Count lines between function start and end
• Exclude comments, blank lines

Severity:

• HIGH: > 100 lines
• MEDIUM: 51-100 lines
• LOW: 40-50 lines (borderline)

Recommendation: Split into smaller functions, apply Single Responsibility

Effort: M (extract logic)

4. God Classes/Modules (> 500 lines)

What: Files with too many responsibilities

Detection:

• Count lines in file (exclude comments)
• Check number of public methods/functions

Severity:

• HIGH: > 1000 lines
• MEDIUM: 501-1000 lines
• LOW: 400-500 lines

Recommendation: Split into multiple files, apply separation of concerns

Effort: L (major refactor)

5. Too Many Parameters (> 5)

What: Functions with excessive parameters

Detection:

• Count function parameters
• Check constructors, methods

Severity:

• MEDIUM: 6-8 parameters
• LOW: 5 parameters (borderline)

Recommendation: Use parameter object, builder pattern, default parameters

Effort: S-M (refactor signature + calls)

6. O(n²) or Worse Algorithms

What: Inefficient nested loops over collections

Detection:

• Nested for loops: for (i) { for (j) { ... } }
• Nested array methods: arr.map(x => arr.filter(...))

Severity:

• HIGH: O(n²) in hot path (API request handler)
• MEDIUM: O(n²) in occasional operations
• LOW: O(n²) on small datasets (n < 100)

Recommendation: Use hash maps, optimize with single pass, use better data structures

Effort: M (algorithm redesign)

7. N+1 Query Patterns

What: ORM lazy loading causing N+1 queries

Detection:

• Find loops with database queries inside
• Check ORM patterns: users.forEach(u => u.getPosts())

Severity:

• CRITICAL: N+1 in API endpoint (performance disaster)
• HIGH: N+1 in frequent operations
• MEDIUM: N+1 in admin panel

Recommendation: Use eager loading, batch queries, JOIN

Effort: M (change ORM query)

8. Constants Management (NEW)

What: Magic numbers/strings, decentralized constants, duplicates

Detection:

Issue	Pattern	Example
Magic numbers	Hardcoded numbers in conditions/calculations	if (status === 2)
Magic strings	Hardcoded strings in comparisons	if (role === 'admin')
Decentralized	Constants scattered across files	MAX_SIZE = 100 in 5 files
Duplicates	Same value multiple times	STATUS_ACTIVE = 1 in 3 places
No central file	Missing constants.ts or config.py	No single source of truth

Severity:

• HIGH: Magic numbers in business logic (payment amounts, statuses)
• MEDIUM: Duplicate constants (same value defined 3+ times)
• MEDIUM: No central constants file
• LOW: Magic strings in logging/debugging

Recommendation:

• Create central constants file (constants.ts, config.py, constants.go)
• Extract magic numbers to named constants: const STATUS_ACTIVE = 1
• Consolidate duplicates, import from central file
• Use enums for related constants

Effort: M (extract constants, update imports, consolidate)

9. Method Signature Quality

What: Poor method contracts reducing readability and maintainability

Detection:

Issue	Pattern	Example
Boolean flag params	>=2 boolean params in signature	def process(data, is_async: bool, skip_validation: bool)
Too many optional params	>=3 optional params with defaults	def query(db, limit=10, offset=0, sort="id", order="asc")
Inconsistent verb naming	Different verbs for same operation type in one module	get_user() vs fetch_account() vs load_profile()
Unclear return type	-> dict, -> Any, -> tuple without TypedDict/NamedTuple	def get_stats() -> dict instead of -> StatsResponse

Severity:

• MEDIUM: Boolean flag params (use enum/strategy), unclear return types
• LOW: Too many optional params, inconsistent naming

Recommendation:

• Boolean flags: replace with enum, strategy pattern, or separate methods
• Optional params: group into config/options dataclass
• Naming: standardize verb conventions per module (get_ for sync, fetch_ for async, etc.)
• Return types: use TypedDict, NamedTuple, or dataclass instead of raw dict/tuple

Effort: S-M (refactor signatures + callers)

10. Side-Effect Cascade Depth

What: Functions triggering cascading chains of external side-effects (DB writes → notifications → metrics → limits).

Detection: MANDATORY READ: shared/references/ai_ready_architecture.md for side-effect markers, false positive exclusions, and opaque sink rules.

• Glob **/services/**/*.{py,ts,js,cs,java} to find service files
• For each public function: check body for side-effect markers (per reference)
• Recursively follow called internal functions for additional markers
• Calculate max chain depth from entry point

Severity:

• HIGH: cascade_depth >= 4
• MEDIUM: cascade_depth = 3
• OK: depth <= 2

Recommendation: Refactor to flat orchestration — extract side-effects into independent sink functions. See reference.

Effort: M-L

Output: Also generate summary Pipe/Sink table per module:

Module	Sinks (0-1)	Shallow Pipes (2)	Deep Pipes (3+)	Sink Ratio

Scoring Algorithm

MANDATORY READ: Load shared/references/audit_scoring.md for unified scoring formula.

Output Format

MANDATORY READ: Load shared/templates/audit_worker_report_template.md for file format.

Write report to {output_dir}/624-quality-{domain}.md (or 624-quality.md in global mode) with category: "Code Quality" and checks: cyclomatic_complexity, deep_nesting, long_methods, god_classes, too_many_params, quadratic_algorithms, n_plus_one, magic_numbers, method_signatures, cascade_depth.

Return summary to coordinator:

Report written: docs/project/.audit/ln-620/{YYYY-MM-DD}/624-quality-orders.md
Score: X.X/10 | Issues: N (C:N H:N M:N L:N)

Critical Rules

• Do not auto-fix: Report only
• Domain-aware scanning: If domain_mode="domain-aware", scan ONLY scan_path (not entire codebase)
• Tag findings: Include domain field in each finding when domain-aware
• Context-aware: Small functions (n < 100) with O(n²) may be acceptable
• Constants detection: Exclude test files, configs, examples
• Metrics tools: Use existing tools when available (ESLint complexity plugin, radon, gocyclo)

Definition of Done

• contextStore parsed (including domain_mode, current_domain, output_dir)
• scan_path determined (domain path or codebase root)
• All 10 checks completed (scoped to scan_path):
  • complexity, nesting, length, god classes, parameters, O(n²), N+1, constants, method signatures, cascade depth
• Findings collected with severity, location, effort, recommendation, domain
• Score calculated
• Report written to {output_dir}/624-quality-{domain}.md (atomic single Write call)
• Summary returned to coordinator

Reference Files

• Worker report template: shared/templates/audit_worker_report_template.md
• Audit scoring formula: shared/references/audit_scoring.md
• Audit output schema: shared/references/audit_output_schema.md
• Code quality rules: references/code_quality_rules.md

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Version: 3.0.0 Last Updated: 2025-12-23