Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/kamiazya/whiteboard/test-layer-selectionnpx skills add kamiazya/whiteboard --skill test-layer-selectiongit clone --depth 1 https://github.com/kamiazya/whiteboardWrote 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.
[](https://agentmods.dev/skills/kamiazya/whiteboard/test-layer-selection)<a href="https://agentmods.dev/skills/kamiazya/whiteboard/test-layer-selection"><img src="https://agentmods.dev/badge/skills/kamiazya/whiteboard/test-layer-selection.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00087 | $0.02209 |
| Opus 5 | $0.00044 | $0.01104 |
| Sonnet 5 | $0.00017 | $0.00442 |
| Haiku 4.5 | $0.00009 | $0.00221 |
Grade A, and why
test-layer-selection scanned grade A with 0 findings 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 2d 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test Layer Selection
Start with the smallest failing test at the nearest layer. Do not jump to broad E2E if a smaller failing test can isolate the bug.
| Layer | Use for | Command |
|---|---|---|
mcp-node |
pure functions, stores, routes, server behavior, persistence logic in packages/mcp-server |
pnpm test --project mcp-node |
canvas-viewer-node |
pure parsing/serialization logic in packages/canvas-viewer with no DOM dependency |
pnpm test --project canvas-viewer-node |
canvas-viewer-jsdom |
packages/canvas-viewer components/hooks when browser layout & pointer behavior are NOT the core risk |
pnpm test --project canvas-viewer-jsdom |
canvas-viewer-browser |
packages/canvas-viewer popovers, dialogs, scroll, focus, keyboard, pointer, restore flows (real browser) |
pnpm test --project canvas-viewer-browser |
web-jsdom |
React components/hooks in apps/web when browser layout & pointer behavior are NOT the core risk |
pnpm test:web-jsdom (jsdom project only) or pnpm --filter @kamiazya/whiteboard-web test (what CI runs: jsdom + web-node) |
web-browser |
apps/web tests needing real browser APIs jsdom lacks: IndexedDB, OPFS, window.showOpenFilePicker. File suffix .browser.test.tsx |
part of pnpm test:browser |
| E2E | real routes, server composition, websocket timing, persistence order, multi-step page flows | promote only when needed |
Notes:
- Browser suites together:
pnpm run test:browser(canvas-viewer-browser+web-browser+canvas-render-browser); traces land under<package>/tmp/vitest-tracesand are kept for FAILING tests only. That trace carries the action log, stacks and screenshots but no DOM view — recording the DOM means recording every resource vite served (302MB against 7.5MB onapps/web's 16 page files; 23GB over a whole run).pnpm run test:browser:traceturns it on, and traces every test including passing ones, so point it at the one failing file. - After the targeted test passes, run the broader suite covering the touched area, then
pnpm test. - Runtime is the source of truth: if behavior disagrees with a test, fix the test or implementation to match real behavior.
- Passing tests alone are not sufficient — manually verify the real behavior (Playwright/Chrome MCP) before locking the scenario into regression coverage.
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.
- 2d ago Changed · +56 lines e23907d0fa11
- 5d ago First seen · 62 lines · 87 tokens per session scan A 499d45835f28
test-layer-selection is a skill published in the GitHub repository kamiazya/whiteboard (6 stars, last pushed today), licensed Apache-2.0. It adds 87 tokens to every session and 2,209 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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