ln-634-test-coverage-auditor

name	ln-634-test-coverage-auditor
description	Identifies missing tests for critical paths (money, security, data integrity, core flows). Use when auditing test coverage gaps.
allowed-tools	Read, Grep, Glob, Bash, mcp__hex-graph__audit_workspace, mcp__hex-line__read_file, mcp__hex-line__grep_search, mcp__hex-line__outline
license	MIT
model	claude-haiku-4-5

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

Coverage Gaps Auditor (L3 Worker)

Type: L3 Worker

Specialized worker identifying missing tests for critical business logic.

Purpose & Scope

• Audit Coverage Gaps (Category 4: High Priority)
• Identify untested critical paths
• Classify by category (Money, Security, Data, Core Flows)
• Calculate compliance score (X/10)

Inputs

MANDATORY READ: Load references/audit_worker_core_contract.md. Tool policy: follow host AGENTS.md MCP preferences; load references/mcp_tool_preferences.md and references/mcp_integration_patterns.md only when host policy is absent or MCP behavior is unclear.

Receives contextStore with: tech_stack, testFilesMetadata, codebase_root, output_dir.

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

Use hex-graph first when hotspots materially improve coverage-gap discovery. Use hex-line first for local code and test 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

Detection policy: use two-layer detection (candidate scan, then context verification); load references/two_layer_detection.md only when the verification method is ambiguous.

1. Parse context -- extract fields, determine scan_path (domain-aware if specified) ELSE: scan_path = codebase_root domain_name = null

2. Identify critical paths in scan_path (not entire codebase)

   • Scan production code in scan_path for money/security/data keywords
   • All Grep/Glob patterns use scan_path (not codebase_root)
   • Example: Grep(pattern="payment|refund|discount", path=scan_path)

3. Check test coverage for each critical path (Layer 1)

   • Search ALL test files for coverage (tests may be in different location than production code)
   • Match by function name, module name, or test description 3b) Context Analysis (Layer 2 -- MANDATORY): For each gap candidate, ask:
   • Is this function already covered by E2E/integration test? -> downgrade to LOW
   • Is this a helper function with <10 lines called from tested code? -> skip
   • Is keyword match a false positive (e.g., paymentIcon() is UI, not payment logic)? -> skip

4. Collect missing tests

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

5. Calculate Score: Count violations by severity, calculate compliance score (X/10)

6. Write Report: Build full markdown report in memory per references/templates/audit_worker_report_template.md, write to {output_dir}/ln-634--{identifier}.md (or {output_dir}/ln-634--{identifier}.md if domain-aware) in single Write call

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

Critical Paths Classification

1. Money Flows (Priority 20+)

What: Any code handling financial transactions

Examples:

• Payment processing (/payment, processPayment())
• Discounts/promotions (calculateDiscount(), applyPromoCode())
• Tax calculations (calculateTax(), getTaxRate())
• Refunds (processRefund(), /refund)
• Invoices/billing (generateInvoice(), createBill())
• Currency conversion (convertCurrency())

Min Priority: 20

Why Critical: Money loss, fraud, legal compliance

2. Security Flows (Priority 20+)

What: Authentication, authorization, encryption

Examples:

• Login/logout (/login, authenticate())
• Token refresh (/refresh-token, refreshAccessToken())
• Password reset (/forgot-password, resetPassword())
• Permissions/RBAC (checkPermission(), hasRole())
• Encryption/hashing (custom crypto logic, NOT bcrypt/argon2)
• API key validation (validateApiKey())

Min Priority: 20

Why Critical: Security breach, data leak, unauthorized access

3. Data Integrity (Priority 15+)

What: CRUD operations, transactions, validation

Examples:

• Critical CRUD (createUser(), deleteOrder(), updateProduct())
• Database transactions (withTransaction())
• Data validation (custom validators, NOT framework defaults)
• Data migrations (runMigration())
• Unique constraints (checkDuplicateEmail())

Min Priority: 15

Why Critical: Data corruption, lost data, inconsistent state

4. Core User Journeys (Priority 15+)

What: Multi-step flows critical to business

Examples:

• Registration -> Email verification -> Onboarding
• Search -> Product details -> Add to cart -> Checkout
• Upload file -> Process -> Download result
• Submit form -> Approval workflow -> Notification

Min Priority: 15

Why Critical: Broken user flow = lost customers

Audit Rules

1. Identify Critical Paths

Process:

• Scan codebase for money-related keywords: payment, refund, discount, tax, price, currency
• Scan for security keywords: auth, login, password, token, permission, encrypt
• Scan for data keywords: transaction, validation, migration, constraint
• Scan for user journeys: multi-step flows in routes/controllers

2. Check Test Coverage

For each critical path:

• Search test files for matching test name/description
• If NO test found -> add to missing tests list
• If test found but inadequate (only positive, no edge cases) -> add to gaps list

3. Categorize Gaps

Severity by Priority:

• CRITICAL: Priority 20+ (Money, Security)
• HIGH: Priority 15-19 (Data, Core Flows)
• MEDIUM: Priority 10-14 (Important but not critical)
• Downgrade when: Function already covered by E2E test -> LOW. Helper with <10 lines called from tested code -> skip

4. Provide Justification

For each missing test:

• Explain WHY it's critical (money loss, security breach, etc.)
• Suggest test type (E2E, Integration, Unit)
• Estimate effort (S/M/L)

Scoring Algorithm

MANDATORY READ: Load references/audit_scoring.md.

Severity mapping by Priority:

• Priority 20+ (Money, Security) missing test -> CRITICAL
• Priority 15-19 (Data Integrity, Core Flows) missing test -> HIGH
• Priority 10-14 (Important) missing test -> MEDIUM
• Priority <10 (Nice-to-have) -> LOW

Output Format

MANDATORY READ: Load 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-634--{identifier}.md (global) or {output_dir}/ln-634--{identifier}.md (domain-aware) with category: "Coverage Gaps" and checks: money_flow_coverage, security_flow_coverage, data_integrity_coverage, core_journey_coverage.

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-634--{identifier}.md
Score: X.X/10 | Issues: N (C:N H:N M:N L:N)

Critical Rules

Apply the already-loaded references/audit_worker_core_contract.md.

• Domain-aware scanning: If domain_mode="domain-aware", scan ONLY scan_path production code (not entire codebase)
• Tag findings: Include domain field in each finding when domain-aware
• Test search scope: Search ALL test files for coverage (tests may be in different location than production code)
• Match by name: Use function name, module name, or test description to match tests to production code

Definition of Done

Apply the already-loaded references/audit_worker_core_contract.md.

• contextStore parsed successfully (including output_dir, domain_mode, current_domain)
• scan_path determined (domain path or codebase root)
• Critical paths identified in scan_path (Money, Security, Data, Core Flows)
• Test coverage checked for each critical path
• Missing tests collected with severity, priority, justification, domain
• Score calculated using penalty algorithm
• Report written to {output_dir}/ln-634--{identifier}.md or ln-634--{identifier}.md (atomic single Write call)
• Summary written per contract

Reference Files

• Audit output schema: references/audit_output_schema.md

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Version: 3.0.0 Last Updated: 2025-12-23