Krt Real World Edge Testing

KRT Real-World Edge Testing

Turn “test the edge cases” into a reproducible failure campaign that exercises the real system and leaves it recoverable. Produce executable cases and evidence, not a generic checklist.

Load References

• Load references/safety.md before designing or running a campaign.
• Load references/campaign-contract.md when defining cases, fixtures, profiles, evidence, state, or completion criteria.
• Load references/failure-taxonomy.md while discovering and prioritizing failure modes. Select relevant categories; do not turn the taxonomy into mandatory busywork.
• Load references/evaluation-pack.md only when evaluating this skill's routing or behavior.

Choose A Mode

• Design: inspect the repository and produce the campaign specification without changing or exercising the system.
• Build: create fixtures, manifests, validators, runners, profiles, and runbook material; do not perform external operations.
• Safe execution: run offline and non-destructive cases after the applicable preflight checks pass.
• Stateful execution: run reversible mutations only after proving target isolation, recording affected resources, and validating recovery.
• Chaos: inject dependency or infrastructure failures only in a verified disposable environment and with explicit authorization for the exact affected target.

Choose the least invasive mode that satisfies the request. A request for “edge cases” does not authorize stateful, chaos, production, credential, or third-party mutations.

Workflow

1. Discover The Real Path

Inspect the repository before asking for facts that can be discovered locally. Map:

• the primary user workflow and its entry points;
• parsers, APIs, persistence, queues, jobs, external dependencies, and infrastructure crossed by that workflow;
• existing test frameworks, schemas, fixtures, error contracts, timeouts, retries, logs, and reset conventions;
• the available environment, its ownership, and whether it is isolated.

State what remains unknown. Do not invent contracts, credentials, target hosts, permissions, or production behavior.

2. Model And Prioritize Failures

Select failure modes from the taxonomy that are plausible for the discovered boundaries. Assign a justified qualitative priority. When evidence supports numerical comparison, optionally score a candidate:

risk = impact (1–5) × likelihood (1–5) × detectability (1–5)

Treat 75–125 as critical, 40–74 as high, 15–39 as medium, and 1–14 as low. Record the rationale for each factor; omit the score rather than manufacturing precision from guesses. Record execution risk separately as read_only, reversible_mutation, isolated_destructive, external_side_effect, or production_forbidden.

Critical cases must be executed or explicitly reported as blocked. Keep low-value permutations out of the primary campaign.

3. Build Executable Cases

Every case must contain the contract described in campaign-contract.md:

Fixture → Setup → Action → Oracle → Recovery

Use deterministic synthetic fixtures with unique canaries. Prefer the project's existing tooling and real production parsers or interfaces over new abstractions or mocks. Every external action needs a timeout.

When the project has no campaign format, copy assets/starter-kit/, adapt the templates, and run python3 scripts/validate_kit.py <kit-directory>. Keep project-native formats when they already provide equivalent guarantees.

Bind related assertions to the same evidence object. For example, source identity and expected text must match within one result; separate “source exists” and “text exists” checks can pass on unrelated records.

4. Verify Offline, Then Preflight

Before contacting the system, verify fixture-manifest integrity, generated paths, canaries, declared duplicates, campaign schema, runner dry-run behavior, and sanitization rules.

Treat preflight as a hard gate. Identify the target, reject ambiguous or shared data, verify dedicated namespaces and mounts, check credentials without printing them, inventory exact affected resources, and prove the recovery mechanism. A renamed database prefix does not prove that a service or bind mount is isolated.

If a required condition fails, stop the affected execution tier and record a concrete blocker. Continue with lower-risk cases when they remain valid.

5. Execute In Risk Order

Run offline validation first, then parser fidelity, dry-run validation, read-only baseline, invalid-input and authorization rejection, reversible mutations, dependency failures, restart/recovery, idempotency/convergence, reset, and post-reset verification.

Capture sanitized evidence for each case. Stop escalation when the next tier lacks authorization, isolation, recovery, or a reliable oracle.

6. Recover And Report

Run the reset procedure for every stateful case and verify convergence, not merely command success. If recovery fails, preserve the resource inventory, stop further mutation, and report failed_recovery.

Report:

• system boundaries and campaign scope;
• cases by pass, fail, blocked, and not run;
• evidence artifact locations and oracle results;
• mutations and recovery status;
• residual risks, manual cases, and missing coverage;
• exact rerun and reset procedures.

Use partially_executed or a specific blocked state when credentials, dependencies, isolation, permissions, or recovery prevent execution. Never map those states to complete.

Guardrails

• Do not mutate production or shared resources without explicit authorization for the exact target and action.
• Do not stop infrastructure, rotate credentials, create public tunnels, change DNS, or delete/trash external data without explicit authorization.
• Never use wildcard deletion or treat an unrelated folder, namespace, database, bucket, or service as disposable.
• Do not print or retain tokens, cookies, authorization headers, private keys, full environment dumps, private documents, or unsanitized infrastructure logs.
• Do not grade subjective generative output without an explicit, observable oracle.
• Do not claim real-path coverage when a case only exercises mocks or a substitute parser.
• Do not hide failed preconditions to continue execution.

Optional Handoffs

• Use krt-security-sentinel to deepen threat modeling or security findings when a campaign crosses authorization, tenancy, secrets, or hostile-content boundaries.
• Use krt-deploy-summoner to inspect deployment isolation and prepare explicitly authorized infrastructure-failure actions.

These specialists are optional. Their absence does not block design, fixture generation, offline validation, or other defensible campaign work.