Dev Property Testing (Gate 5)

Overview

Ensure domain logic has property-based tests to verify invariants hold for all randomly generated inputs.

Core principle: Property tests verify universal truths about your domain. If "balance is never negative" is a rule, test it with thousands of random inputs.

<block_condition>

• No property functions = FAIL
• Any counterexample found = FAIL (fix and re-run)
• No quick.Check usage = FAIL </block_condition>

CRITICAL: Role Clarification

This skill ORCHESTRATES. QA Analyst Agent (property mode) EXECUTES.

Who	Responsibility
This Skill	Gather requirements, dispatch agent, track iterations
QA Analyst Agent	Write property tests, run quick.Check, report counterexamples

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Standards Source (Cache-First Pattern)

Standards Source (Cache-First Pattern): This sub-skill reads standards from state.cached_standards populated by dev-cycle Step 1.5. If invoked outside a cycle (standalone), it falls back to direct WebFetch with a warning. See shared-patterns/standards-cache-protocol.md for protocol details.

Standards Reference

MANDATORY: Load testing-property.md standards via the cache-first pattern below.

URL: https://raw.githubusercontent.com/LerianStudio/ring/main/dev-team/docs/standards/golang/testing-property.md

Cache-first loading protocol: For each required standards URL: IF state.cached_standards[url] exists: → Read content from state.cached_standards[url].content → Log: "Using cached standard: {url} (fetched {state.cached_standards[url].fetched_at})" ELSE: → WebFetch url (fallback — should not happen if orchestrator ran Step 1.5) → Log warning: "Standard {url} was not pre-cached; fetched inline"

<fetch_required> https://raw.githubusercontent.com/LerianStudio/ring/main/dev-team/docs/standards/golang/testing-property.md </fetch_required>

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Step 1: Validate Input

REQUIRED INPUT:
- unit_id: [TASK id — runs at task cadence, not per subtask]
- implementation_files: [union of changed files across all subtasks of this task]
- language: [go]
- gate0_handoffs: [array of per-subtask Gate 0 handoffs — one entry per subtask]

OPTIONAL INPUT:
- domain_invariants: [list of invariants to verify]
- gate4_handoff: [full Gate 4 output]

if any REQUIRED input is missing:
  → STOP and report: "Missing required input: [field]"

Step 2: Dispatch QA Analyst Agent (Property Mode)

Task tool:
  subagent_type: "ring:qa-analyst"
  prompt: |
    **MODE:** PROPERTY-BASED TESTING (Gate 5)

    **Standards:** Load testing-property.md

    **Input:**
    - Unit ID: {unit_id}
    - Implementation Files: {implementation_files}
    - Language: {language}
    - Domain Invariants: {domain_invariants}

    **Requirements:**
    1. Identify domain invariants from code
    2. Create property functions (TestProperty_{Subject}_{Property} naming)
    3. Use testing/quick.Check for verification
    4. Report any counterexamples found

    **Output Sections Required:**
    - ## Property Testing Summary
    - ## Properties Report
    - ## Handoff to Next Gate

Step 3: Evaluate Results

Parse agent output:

if "Status: PASS" in output:
  → Gate 5 PASSED
  → Return success with metrics

if "Status: FAIL" in output:
  → Dispatch fix to implementation agent
  → Re-run property tests (max 3 iterations)
  → If still failing: ESCALATE to user

Step 4: Generate Output

## Property Testing Summary
**Status:** {PASS|FAIL}
**Properties Tested:** {count}
**Properties Passed:** {count}
**Counterexamples Found:** {count}

## Properties Report
| Property | Subject | Status |
|----------|---------|--------|
| {property_name} | {subject} | {PASS|FAIL} |

## Handoff to Next Gate
- Ready for Gate 6 (Integration Testing): {YES|NO}
- Iterations: {count}

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Common Properties to Test

Domain	Example Properties
Money/Currency	Amount never negative, currency always valid, addition commutative
User/Account	Email always valid format, password meets policy, status transitions valid
Order/Transaction	Total equals sum of items, quantity always positive, state machine valid
Date/Time	Start before end, duration always positive, timezone valid

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Severity Calibration

Severity	Criteria	Examples
CRITICAL	Counterexample found, invariant violated	quick.Check finds input that breaks property
HIGH	No property tests, missing quick.Check	Zero TestProperty_ functions, no testing/quick usage
MEDIUM	Incomplete properties, naming issues	Missing domain invariants, non-standard names
LOW	Documentation, optimization	Missing property descriptions, generator tuning

Report all severities. CRITICAL = immediate fix (invariant broken). HIGH = fix before gate pass. MEDIUM = fix in iteration. LOW = document.

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Anti-Rationalization Table

Rationalization	Why It's WRONG	Required Action
"Unit tests verify logic"	Unit tests verify SPECIFIC cases. Properties verify ALL cases.	Write property tests
"No domain invariants"	Every domain has rules. "ID is unique", "amount > 0", etc.	Identify and test invariants
"Too abstract"	Properties are concrete: "user.age >= 0 for all users".	Write property tests
"quick.Check is slow"	Milliseconds to find bugs that would take hours to discover.	Write property tests

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