QA Investigation

A persistent, file-backed investigation journal for a specific failing test. This is the execution layer: it resolves a concrete failure. It does not validate strategy or architecture (grill-me-qa) nor generate QA deliverables (qa-manual-istqb).

The core idea: your context window is volatile RAM; the filesystem is persistent disk. Writing goals, evidence, and decisions to markdown prevents context drift during a long investigation.

When to Use This Skill

• A test fails intermittently (flaky) or deterministically (bug), and you need the root cause.
• The investigation spans many tool calls, multiple runs, or more than one session.
• You want a durable record of what you found, decided, and why.

When NOT to Use This Skill

• Authoring a test from scratch — use the relevant automation/framework skill.
• Designing a framework or coverage strategy — strategy validation (grill-me-qa) or artifact generation (qa-manual-istqb).
• Simple questions or quick lookups (fewer than ~5 tool calls).
• General review of non-test production code.

The boundary is not "is it a selector / browser issue / timeout" — any of those can be worth investigating. The boundary is whether the request needs a persistent, multi-step root-cause investigation or is a one-shot tactical task. If uncovering the why takes evidence, runs, and iteration, use this skill.

Tool Agnosticism

This method is independent of any test framework — web, API, mobile, embedded, unit, load. Terms like "browser", "selector", "network requests", or "CI vs local" are illustrative, not requirements; substitute the equivalent in your stack.

Core Process

The phases are the same whether the failure is flaky or a deterministic bug. The skill discovers the classification during triage — it does not assume it up front.

Phase 1: Reproduction & Triage

• Reproduce reliably; isolate variables (parallelism, repeat count, environment, data/state).
• Determine: intermittent (flaky), deterministic (bug), or non-reproducible? This is a finding, not an input.
• Record the classification and the evidence that supports it.
• Goal: a confirmed reproduction or a documented non-reproducible failure.

Non-reproducible path: if the failure cannot be reproduced after a bounded number of attempts, do not force a label. Record it as non-reproducible with partial evidence, note the suspected nature (infrastructure, app logic, or test-side timing), and escalate or flag for observation. Log the decision and reason to qainvestigationfindings.md. See [Flow](./references/flow.md) for detail.

Phase 2: Evidence Collection

• Capture logs, stack traces, screenshots, traces, retry counts, dependency activity, timings.
• Multimodal content (images, page/dependency data, PDFs) does not persist in context — write it to qainvestigationfindings.md as text immediately.
• Redact sensitive data (tokens, cookies, credentials, email addresses, PII) before persisting; do not write raw screenshots, traces, logs, or network captures verbatim — summarize them in text with sensitive parts masked.
• Note environment specifics: build/version, platform, device, data conditions, worker count.
• Goal: enough evidence for a defensible hypothesis.

Phase 3: Hypothesis & Root Cause

• Form the leading hypothesis (race condition, timing, selector/view issue, app bug, environment, shared state, data flakiness).
• Test it in a way that can reject it; confirm or reject; record the confirmed cause and the evidence.
• Goal: a confirmed root cause, not a guess.

Phase 4: Fix & Validation

• Decide the fix (test-side vs product-side) and, critically, the alternatives you rejected and why.
• Apply it, then validate stability over repeated runs.
• Goal: a stable, verified fix with a documented decision.

Phase 5: Prevention

• Decide how to prevent recurrence: a shared helper, a lint rule, documentation, a regression guard.
• Record the preventive action(s).
• Goal: the failure does not come back silently.

File Purposes

Scale the file scope to the investment level (triaged at the start — see [Flow](./references/flow.md)). Higher value = fuller record; lower value = leaner:

Each investigation creates the files above in the project root:

Critical Rules

1. Create the plan first — non-negotiable; the plan is your persistent memory. For a P3 (low-value) case, the findings file is the plan — create that first.
2. 2-Action Rule — after every 2 read/search ops, save key findings to qainvestigationfindings.md.
3. Read before decide — re-read the plan before major decisions.
4. Update after act — mark phase status, log errors, note files changed.
5. Log ALL errors — with attempt number and resolution.
6. Never repeat failures — if an action failed, the next must differ.
7. Classify after reproducing, not before — a wrong early label poisons the investigation.

References

• [Flow](./references/flow.md) — methodology detail, effort triage, completion criteria, file lifecycle, error protocols, anti-patterns
• [Templates](./references/templates.md) — starter templates for the three investigation files
• [Examples](./references/examples.md) — flaky, bug, and non-reproducible cases