ln-633-test-value-auditor

name	ln-633-test-value-auditor
description	Risk-Based Value audit worker (L3). Calculates Usefulness Score = Impact (1-5) × Probability (1-5) for each test. Returns KEEP/REVIEW/REMOVE decisions based on thresholds (≥15 KEEP, 10-14 REVIEW, <10 REMOVE).
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.

Risk-Based Value Auditor (L3 Worker)

Specialized worker calculating Usefulness Score for each test.

Purpose & Scope

• Worker in ln-630 coordinator pipeline
• Audit Risk-Based Value (Category 3: Critical Priority)
• Calculate Usefulness Score = Impact × Probability
• Make KEEP/REVIEW/REMOVE decisions
• Calculate compliance score (X/10)

Inputs (from Coordinator)

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

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

Workflow

1. Parse Context: Extract tech stack, Impact/Probability matrices, test file list, output_dir from contextStore
2. Calculate Scores: For each test: calculate Usefulness Score = Impact x Probability
3. Classify Decisions: KEEP (>=15), REVIEW (10-14), REMOVE (<10)
4. Collect Findings: Record each REVIEW/REMOVE decision with severity, location (file:line), effort estimate (S/M/L), recommendation
5. Calculate Score: Count violations by severity, calculate compliance score (X/10)
6. Write Report: Build full markdown report in memory per shared/templates/audit_worker_report_template.md, write to {output_dir}/633-test-value.md in single Write call
7. Return Summary: Return minimal summary to coordinator (see Output Format)

Usefulness Score Calculation

Formula

Usefulness Score = Business Impact (1-5) × Failure Probability (1-5)

Impact Scoring (1-5)

Score	Impact	Examples
5	Critical	Money loss, security breach, data corruption
4	High	Core flow breaks (checkout, login, registration)
3	Medium	Feature partially broken, degraded UX
2	Low	Minor UX issue, cosmetic bug
1	Trivial	Cosmetic issue, no user impact

Probability Scoring (1-5)

Score	Probability	Indicators
5	Very High	Complex algorithm, new technology, many dependencies
4	High	Multiple dependencies, concurrency, edge cases
3	Medium	Standard CRUD, framework defaults, established patterns
2	Low	Simple logic, well-established library, trivial operation
1	Very Low	Trivial assignment, framework-generated, impossible to break

Decision Thresholds

Score Range	Decision	Action
≥15	KEEP	Test is valuable, maintain it
10-14	REVIEW	Consider if E2E already covers this
<10	REMOVE	Delete test, not worth maintenance cost

Scoring Examples

Example 1: Payment Processing Test

Test: "processPayment calculates discount correctly"
Impact: 5 (Critical — money calculation)
Probability: 4 (High — complex algorithm, multiple payment gateways)
Usefulness Score = 5 × 4 = 20
Decision: KEEP

Example 2: Email Validation Test

Test: "validateEmail returns true for valid email"
Impact: 2 (Low — minor UX issue if broken)
Probability: 2 (Low — simple regex, well-tested library)
Usefulness Score = 2 × 2 = 4
Decision: REMOVE (likely already covered by E2E registration test)

Example 3: Login Flow Test

Test: "login with valid credentials returns JWT"
Impact: 4 (High — core flow)
Probability: 3 (Medium — standard auth flow)
Usefulness Score = 4 × 3 = 12
Decision: REVIEW (if E2E covers, remove; else keep)

Audit Rules

1. Calculate Score for Each Test

Process:

• Read test file, extract test name/description
• Analyze code under test (CUT)
• Determine Impact (1-5)
• Determine Probability (1-5)
• Calculate Usefulness Score

2. Classify Decisions

KEEP (≥15):

• High-value tests (money, security, data integrity)
• Core flows (checkout, login)
• Complex algorithms

REVIEW (10-14):

• Medium-value tests
• Question: "Is this already covered by E2E?"
• If yes → REMOVE; if no → KEEP

REMOVE (<10):

• Low-value tests (cosmetic, trivial)
• Framework/library tests
• Duplicates of E2E tests

3. Identify Patterns

Common low-value tests (<10):

• Testing framework behavior
• Testing trivial getters/setters
• Testing constant values
• Testing type annotations

Scoring Algorithm

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

Severity mapping by Usefulness Score:

• Score <5 → CRITICAL (test wastes significant maintenance effort)
• Score 5-9 → HIGH (test likely wasteful)
• Score 10-14 → MEDIUM (review needed)
• Score ≥15 → no issue (KEEP)

Output Format

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

Write report to {output_dir}/633-test-value.md with category: "Risk-Based Value" and checks: usefulness_score, remove_candidates, review_candidates.

Return summary to coordinator:

Report written: docs/project/.audit/ln-630/{YYYY-MM-DD}/633-test-value.md
Score: X.X/10 | Issues: N (C:N H:N M:N L:N)

Note: Tests with Usefulness Score >=15 (KEEP) are NOT included in findings -- only issues are reported.

Critical Rules

• Do not auto-fix: Report only
• Effort realism: S = <1h, M = 1-4h, L = >4h
• Score objectivity: Base Impact and Probability on code analysis, not assumptions
• KEEP tests not reported: Only REVIEW and REMOVE decisions appear in findings
• Cross-reference E2E: REVIEW decisions depend on whether E2E already covers the scenario

Definition of Done

• contextStore parsed successfully (including output_dir)
• Usefulness Score calculated for each test (Impact x Probability)
• Decisions classified: KEEP (>=15), REVIEW (10-14), REMOVE (<10)
• Findings collected with severity, location, effort, recommendation
• Score calculated using penalty algorithm
• Report written to {output_dir}/633-test-value.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

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Version: 3.0.0 Last Updated: 2025-12-23