What is validation-and-qa?

Repository-specific guidance for deciding how to write and judge tests in the Cambridge Beer Festival app. It describes which checks prove logic, screen appearance, API behavior, routing, and real-device behavior.

Use it before writing tests, reviewing test quality, updating screenshot goldens, or deciding which test level a change needs.

It prevents a change from being called tested when the chosen check is too weak to prove that the change works.

How richardthe3rd/cambridge-beer-festival-app configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to richardthe3rd/cambridge-beer-festival-app. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/richardthe3rd/cambridge-beer-festival-app/main/.claude/skills/validation-and-qa/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/richardthe3rd/cambridge-beer-festival-app

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa/github.svg)](https://agentmods.dev/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa)

Your own site

<a href="https://agentmods.dev/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa"><img src="https://agentmods.dev/badge/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa"><img src="https://agentmods.dev/badge/skills/richardthe3rd/cambridge-beer-festival-app/validation-and-qa.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 242 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 7,378 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00242	$0.07378
Opus 5	$0.00121	$0.03689
Sonnet 5	$0.00048	$0.01476
Haiku 4.5	$0.00024	$0.00738

Measured 5d ago against content hash f8116638439a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

validation-and-qa scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

const response = await worker.fetch(request, env, ctx);

.claude/skills/validation-and-qa/SKILL.md · 677 lines

How it starts

The opening of the file, as written. The whole thing — 677 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Validation and QA

How to decide a change is actually correct in this repo, and how to write the test that proves it. Every skeleton below is copied from a real, currently passing test file — file:line citations let you go read the full context.

1. The evidence hierarchy

Ranked by how much it actually proves, strongest first. A change is not "tested" until it clears the layer appropriate to what changed — reaching for a weaker layer when a stronger one applies is the shallow-test failure mode in §2.

Rank	Layer	Proves	Command
1	Unit / widget tests (`test/`, `flutter_test`)	Actual logic and rendered behavior, in-process	`./bin/mise run test`
2	Golden screenshots (`test/goldens/`)	Pixel-level layout regressions	`./bin/mise run test`, update via `./bin/mise run goldens:update`
3	Worker vitest (`cloudflare-worker/test/`, workerd runtime)	Real HTTP/D1 behavior of the API worker	`./bin/mise run test:worker`
4	Playwright URL/ARIA smoke (`test-e2e/`)	Routing mechanics and gross console errors on a deployed-shape build	`MISE_ENV=dev ./bin/mise run test:e2e`
5	Manual device testing	Real user experience	Human only — see below

The Playwright hard limitation (read this before trusting an e2e pass)

Flutter web renders the entire UI to a single <canvas> element. Playwright drives the DOM/accessibility tree, not the canvas pixels. This means Playwright can never verify what the UI actually looks like or says — it can only prove URL/routing mechanics, gross JS errors, and the ARIA/lang baseline Flutter exposes around the canvas.

Concretely: a route can return HTTP 200 and Playwright can pass, while the screen underneath is rendering a full-page error state. A 200 + "no critical console errors" is not evidence the feature works — it is evidence the app booted. This is codified in docs/adr/0005-e2e-testing-strategy.md, which also records why the alternative (Patrol + Firebase Test Lab — native device E2E) was evaluated and rejected: 4-5 week setup cost, Firebase Test Lab free-tier cap of 15 tests/day, and Flutter widget tests already covering interaction flows. Reconsider Patrol only if the triggers in that ADR fire (device-specific concerns: permissions, system dialogs, push notifications).

Read the full file on GitHub · 677 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

5d ago Changed · +2 lines f8116638439a
12d ago First seen · 675 lines · 242 tokens per session scan A d216dbfc8357

Subscribe to this mod's changes

validation-and-qa is a skill published in the GitHub repository richardthe3rd/cambridge-beer-festival-app (2 stars, last pushed yesterday), licensed MIT. It adds 242 tokens to every session and 7,378 once invoked, about $0.0012 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Testing

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cambridge-beer-festival-app: Skill for Claude Code