ck-scenario

name	ck:scenario
description	Generate comprehensive edge cases and test scenarios by decomposing features across 12 dimensions. Use for pre-implementation risk discovery, QA planning, regression design, and iterative saturation when coverage must be exhaustive.
user-invocable	true
when_to_use	Invoke to expand requirements into edge cases and QA scenarios.
category	utilities
keywords	["edge-cases","test-scenarios","dimensions","saturation","iterations"]
argument-hint	<file path or feature description> [--iterations N] [--saturation]
metadata	{"author":"claudekit","attribution":"Scenario exploration pattern adapted from autoresearch by Udit Goenka (MIT)","license":"MIT","version":"1.1.0"}

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.

Supports two modes:

• One-shot (default): single pass, 3–5 scenarios per relevant dimension. Fast, backwards-compatible.
• Iterative (--iterations N or --saturation): loop until bounded count or novelty exhausted.

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
• Deep pre-release coverage audit (--saturation)

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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Flags

Flag	Default	Purpose
--iterations N	—	Bounded loop: run exactly N iterations, then stop with summary
--saturation	off	Saturation loop: keep iterating until 2 consecutive iterations produce no novel scenarios
--domain <type>	auto	Domain hint: software, product, business, security, marketing
--focus <dim>	auto	Prioritize dimension: edge-cases, failures, security, scale
--format <type>	table	Output format: table, use-cases, test-scenarios, threat-scenarios

When neither --iterations nor --saturation is set: one-shot mode (original behavior, default).

---

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

One-Shot Mode (default)

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

Iterative Mode (--iterations N or --saturation)

Iterative mode runs the loop described in references/saturation-loop.md. Summary:

1. Read target and build understanding (actors, components, preconditions)
2. Filter dimensions — same as one-shot
3. Loop — each iteration: a. Pick highest-priority unexplored dimension or combination b. Generate one concrete situation (specific trigger, flow, expected outcome) c. Classify against all previously kept situations:
   • New: different dimension AND different trigger/precondition → KEEP
   • Variant: same dimension but different actor, data, or outcome → KEEP
   • Duplicate: same dimension + same trigger + same outcome → DISCARD
   • Out of scope / Low value → DISCARD, log reason d. If kept: expand edge cases (what-if, boundary, interruption, ordering, missing data, stale data) e. Log row to scenario-results.tsv f. Every 5 iterations: print progress summary (see format below)
4. Halt:
   • --iterations N: stop after N iterations
   • --saturation: stop when 2 consecutive iterations produce zero New classifications
5. Output final summary with coverage matrix and composite score

Force dimension rotation after 3 consecutive same-dimension iterations. Rotate through: Dimension walk → Combination → Negation → Amplification → Persona shift → Temporal shift

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

One-Shot

## 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

Iterative — Progress Summary (every 5 iterations)

=== Scenario Progress (iteration 15) ===
Scenarios kept:    12  (8 new, 4 variants)
Discarded:          3  (2 duplicates, 1 out-of-scope)
Dimensions covered: 7/12 (58%)
Edge cases found:  18
Severity:          2 Critical, 4 High, 8 Medium, 4 Low
Coverage gaps:     scale, temporal, recovery

Iterative — TSV Log (scenario-results.tsv)

iteration	dimension	classification	severity	title	description	parent
1	happy_path	new	-	Successful checkout	User completes standard checkout	-
2	error_path	new	HIGH	Payment declined	Card rejected during checkout	-
3	edge_case	duplicate	-	Empty cart	Already covered by #1	#1

Iterative — Final Summary

## Scenario Report: [target]  (iterations: N)

[Full table of kept scenarios, grouped by dimension]

### Coverage Matrix
[dimension × severity grid]

### Composite Score: NNN
  scenarios_generated * 10  = X
  edge_cases_found * 15     = X
  dimensions_covered * 30   = X
  unique_actors * 5         = X
  high_severity * 3         = X

### Saturation
Halted: [after N iterations — bounded] | [saturation — 2 consecutive iterations with no novel cases]

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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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Reference

Saturation loop mechanics, novelty detection algorithm, and generation strategies: → claude/skills/ck-scenario/references/saturation-loop.md

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Example Invocations

# One-shot (default — backwards compatible)
/ck:scenario src/api/payment.ts
/ck:scenario "User registration with OAuth providers"

# Bounded iterative — exactly 25 iterations
/ck:scenario src/api/payment.ts --iterations 25

# Saturation — stop when coverage exhausted
/ck:scenario "Add multi-tenancy to the database layer" --saturation

# Saturation with domain hint for priority dimension ordering
/ck:scenario src/middleware/auth.ts --saturation --domain security

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Lineage

Faithful absorption (in scope) of upstream /autoresearch:scenario (uditgoenka/autoresearch, MIT). The local version supports both one-shot generation and the iterative saturation loop (closed in #729).

See /ck:autoresearch for the full family map.