wjttc-tester – Coding skill for AI agents

WJTTC Championship Tester

"We break things so others never have to know they were broken."

Apply F1-inspired standards to software testing. When brakes must work flawlessly at race pace, so must the code in production. This skill executes test plans and files reports — it is the driver, not the engineer. To plan and generate the suite, use wjttc-builder.

When to use this skill

• Running an existing or just-written test plan and reporting outcomes
• Reproducing and root-causing a reported bug
• Edge-case / error-handling / regression validation
• Auditing whether the suite's CI signal can still be trusted
• Producing a WJTTC report with a tier verdict

The WJTTC five tiers

Triage every test by blast radius. The first three set severity; Tyre and Pit cover durability and the release gate.

| Tier | Symbol | Meaning | Examples |

|------|--------|---------|----------|

| Brake | 🚨 | Life-critical — failure is catastrophic | data loss, auth bypass, payment errors, destructive ops without confirm |

| Engine | ⚡ | Performance-critical — wrong results / poor UX | API accuracy, data transforms, calculations, format compliance, perf |

| Aero | 🏁 | Polish & edge cases — minor inconvenience | UI quirks, rare message formatting, optional-feature edges, docs |

| Tyre | 🛞 | Durability under load — degradation over time | stress/volume, concurrency, memory growth, large inputs |

| Pit | 🔧 | Release gate — the stop that lets you go | smoke/regression suite, CI green, the WJTTC report filed |

Test Brake first. If the brakes don't work, nothing else matters.

Step 0 — Signal Integrity pre-audit (run BEFORE adding/running anything new)

Red CI is a contract: it must always mean "stop, look, fix." A suite with high coverage but flaky reds is *less* trustworthy than a smaller suite with zero false alarms — because the team has stopped reading the reds. Fix the signal before you add more tests.

Method — classify the last 30 days of CI failures:

| Bucket | Definition | Verdict |

|--------|-----------|---------|

| Real bug | Red mapped to a real defect; fixed by a code change | ✓ Signal worked |

| Flake | Timing/network/concurrency noise; passed on rerun, no code change | ✗ Test design defect |

| Infra | Missing secret, runner image change, upstream dep — not the code | ✗ Workflow design defect |

Signal Integrity Score: SI = Real bugs / (Real bugs + Flakes + Infra) × 100. If the denominator is zero, report N/A; a passing rerun alone does not establish a flake.

| SI % | Verdict | Action |

|------|---------|--------|

| 100% | ✪ | Maintain — exemplary signal |

| 95–99% | ★ Championship | Annotate any flake immediately |

| 85–94% | ◇ Acceptable | Schedule the flake-class fix this sprint |

| 70–84% | ● Eroding | Stop adding tests — fix flakes first |

| <70% | ○ Dead signal | Block merges until signal restored |

Eliminate on sight: hard absolute-time perf asserts on shared runners (expect(t).toBeLessThan(30)) → move to a non-gating workflow; network calls in the main suite → mock at the boundary; concurrency tests without explicit ordering; optional secret-dependent tests → explicitly report blocked/not-run. Missing required evidence must fail closed; never grey-skip a required release gate.

The inverse rule: green CI that passes while something is broken is equally a violation. If a real bug shipped despite green, write the regression test BEFORE the fix lands.

Repository protection and required checks remain authoritative. CI is supporting infrastructure for the human + AI audit; flaky CI wastes the audit's bandwidth. Signal Integrity keeps CI worthy of the conversation.

Execution loop

1. Scope — what should it do? happy path, edges, failure modes, perf targets, tier of each.

2. Audit signal (Step 0) before trusting or extending the suite.

3. Run each test: set up, prepare data, execute, observe actual vs expected, record pass/fail/blocked, capture evidence on failure.

4. Reproduce every failure deterministically; root-cause it; note the fix.

5. Tier coverage check — confirm every test is tiered:

   faf wjttc --path tests          # audit tier coverage (vendor-neutral)
   faf wjttc --strict --json       # CI gate: non-zero if any test is untiered
   

6. Report — file the WJTTC report (below), then surface the tier verdict.

WJTTC report format

Save reports to ./wjttc-reports/ in the project under test (or a path the user specifies). Never write to an absolute/personal path. Name files YYYY-MM-DD-{project}-{feature}-tests.yaml.

---
# WJTTC Test Report
project: "project-name"
feature: "feature-being-tested"
date: "2026-06-26"
tier: "Engine"            # Brake | Engine | Aero | Tyre | Pit
result: "PASS"            # PASS | FAIL | BLOCKED
environment: "OS, runtime version, key deps"

## Summary
objective: What was tested
totals: { total: 25, passed: 23, failed: 2, blocked: 0, pass_rate: "92%" }

## Failures
- name: "Long-string handling"
  tier: "Engine ⚡"
  status: "FAIL"
  steps: ["...", "..."]
  expected: "Handle gracefully"
  actual: "Crash"
  error: "RangeError: ..."
  root_cause: "Unbounded buffer"
  fix: "Cap input length / stream"

## Edge cases
- { case: "Empty string", input: "''", expected: "error", actual: "error", status: "PASS" }
- { case: "Unicode", input: "🏎️", expected: "stored", actual: "stored", status: "PASS" }

## Performance
- { op: "file read",  target: "<50ms", actual: "18ms", status: "PASS" }
- { op: "parse YAML", target: "<50ms", actual: "12ms", status: "PASS" }

## Bugs found
- id: 1
  title: "..."
  severity: "Brake"      # tier doubles as severity
  reproducibility: "Always"
  impact: "Who is affected, how serious"
  fix: "..."

## Coverage
tested:     ["happy path", "edges", "error handling", "perf"]
not_tested: ["concurrent access", "files >100MB"]

## Verdict
tier: "◆ Silver"          # from the tier table below
to_next: ["Fix 2 failing Engine tests", "Add Tyre concurrency tests"]

Tier verdict

Map the pass rate (or SI score) to the single canonical FAF tier ladder. No second ladder, no medals.

| Score | Tier | Symbol |

|-------|------|--------|

| 100% | Trophy | ✪ |

| 99% | Gold | ★ |

| 95% | Silver | ◆ |

| 85% | Bronze | ◇ |

| 70% | Green | ● |

| 55% | Yellow | ● |

| 1% | Red | ○ |

| 0% | White | ♡ |

The FAF score is deterministic — same input, same score. A test report should be just as falsifiable: every verdict traces to a reproducible run. FAF doesn't lie.

WJTTC method notes

• Test with real data, not just sanitized inputs — anonymized production data, messy inputs, production-like volume.
• Document every failure so it can be reproduced: what failed, how to repro, why it matters, how to fix.
• Tier before you test — severity is the tier, so triage first; faf wjttc enforces that nothing ships untiered.
• Wire it into CI with TAF receipts so the report is part of the record, not a one-off:

  faf taf setup --write     # create .github/workflows/taf.yml (test receipts)
  faf score --json          # deterministic score snapshot for the receipt
  

Quick checklist (before release)

• [ ] Signal Integrity audited (SI ≥ 85%)
• [ ] Brake tests pass — zero tolerance
• [ ] Edges + error handling tested
• [ ] Tyre: behaves under load / concurrency
• [ ] faf wjttc --strict green — every test tiered
• [ ] Regression (Pit) suite passes
• [ ] WJTTC report filed in ./wjttc-reports/
• [ ] Pass rate recorded; every required test passes and required release criteria are met. No aggregate pass rate establishes production readiness.

Resources

• Website: https://faf.one · Skills Site: https://skills.faf.one
• faf-cli: https://github.com/Wolfe-Jam/faf-cli
• Sibling skill: wjttc-builder (plan + generate the suite)

---

*Made with 🧡 by wolfejam.dev — "We break things so others never have to know they were broken."*

Limitations

• Use this skill only when the task clearly matches its upstream source and local project context.
• Verify commands, generated code, dependencies, credentials, and external service behavior before applying changes.
• Do not treat examples as a substitute for environment-specific tests, security review, or user approval for destructive or costly actions.