quanganh208/ck:scenario

ck:scenario — Edge Case & Scenario Explorer

Decompose any feature or code path across 12 dimensions to surface edge cases, risks, and test targets before implementation begins.

When to Use

• Before implementing complex or stateful features
• Before writing tests (generates test targets)
• Risk assessment during planning or code review
• API design review — surface contract edge cases early

When NOT to Use

• Trivial single-line changes or cosmetic UI tweaks
• Already well-tested, stable code with no recent modifications
• Pure configuration changes with no logic paths

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12 Decomposition Dimensions

Not all 12 apply to every feature. Identify relevant dimensions first, then generate scenarios only for those.

| # | Dimension | What to Look For | |---|-----------|------------------| | 1 | User Types | admin, guest, banned, new user, power user, bot/scraper | | 2 | Input Extremes | empty, null, max length, unicode, special chars, SQL/script injection | | 3 | Timing | concurrent access, race conditions, timeout, slow network, retry storms | | 4 | Scale | 0 items, 1 item, 1M items, pagination boundary, cursor wrap | | 5 | State Transitions | first use, mid-flow abort, resume after crash, partial completion | | 6 | Environment | mobile/low-end CPU, no JS, screen reader, proxy/VPN, different timezone/locale | | 7 | Error Cascades | DB down, API timeout, disk full, OOM, network partition, partial write | | 8 | Authorization | expired token, wrong role, shared/public link, CORS, CSRF, privilege escalation | | 9 | Data Integrity | duplicate entries, orphan references, encoding mismatch, concurrent schema migration | | 10 | Integration | webhook replay, API version mismatch, third-party outage, contract drift | | 11 | Compliance | GDPR deletion request, audit logging gap, data retention, accidental PII exposure | | 12 | Business Logic | edge pricing (zero/negative), coupon stacking, refund after partial delivery, free tier limits |

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Workflow

1. Read target file(s) or parse feature description from argument
2. Filter dimensions — mark which of the 12 apply; skip irrelevant ones explicitly
3. Generate 3–5 scenarios per relevant dimension
4. Categorize severity — Critical / High / Medium / Low
5. Output as structured table (see format below)
6. Summarize total scenario count by severity

Severity Criteria

| Level | Meaning | |-------|---------| | Critical | Data loss, security breach, auth bypass, silent corruption | | High | Feature broken for a subset of users, data inconsistency | | Medium | Degraded UX, recoverable error not surfaced to user | | Low | Minor visual glitch, non-blocking warning |

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Output Format

## Scenario Report: [target]

Dimensions analyzed: [list]
Dimensions skipped: [list + reason]

| # | Dimension | Scenario | Severity | Expected Behavior |
|---|-----------|----------|----------|-------------------|
| 1 | Input Extremes | Empty string for required name field | High | Return 400 with field error |
| 2 | Authorization | Expired JWT accessing protected route | Critical | Redirect to login, invalidate session |
| 3 | Timing | Two users submit same form simultaneously | High | Idempotency key or conflict error |

### Summary
- Critical: N
- High: N
- Medium: N
- Low: N
- Total: N scenarios across X dimensions

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Integration with Other Skills

| Next Step | Skill | How | |-----------|-------|-----| | Generate test cases from scenarios | ck:test | Pass scenario table as input context | | Inform implementation plan risks | ck:plan | Paste Critical/High rows into risk assessment | | Deep persona debate on top risks | ck:predict | Feed Critical scenarios as the change proposal |

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Example Invocations

/ck:scenario src/api/payment.ts
/ck:scenario "User registration with OAuth providers"
/ck:scenario src/middleware/auth.ts
/ck:scenario "Add multi-tenancy to the database layer"