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/franrom/pupila/vitestnpx skills add FranRom/pupila --skill vitestgit clone --depth 1 https://github.com/FranRom/pupilaWrote 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/franrom/pupila/vitest)<a href="https://agentmods.dev/skills/franrom/pupila/vitest"><img src="https://agentmods.dev/badge/skills/franrom/pupila/vitest.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 | $0.00036 | $0.00710 |
| Opus 5 | $0.00018 | $0.00355 |
| Sonnet 5 | $0.00007 | $0.00142 |
| Haiku 4.5 | $0.00004 | $0.00071 |
Grade A, and why
vitest 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 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.
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.
This is a copy
88% identical to vitest — 72 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Vitest = next-gen test framework powered by Vite. Jest-compatible API. Native ESM, TypeScript, JSX. Shares Vite config, transformers, resolvers, plugins.
Key Features:
- Vite-native: Vite pipeline, fast HMR-like test updates
- Jest-compatible: drop-in for most Jest suites
- Smart watch: reruns affected tests via module graph
- Native ESM, TypeScript, JSX. No config.
- Multi-threaded parallel execution
- Coverage via V8 or Istanbul
- Snapshots, mocks, spies
Skill based on Vitest 3.x, generated 2026-01-28.
Core
| Topic | Description | Reference |
|---|---|---|
| Configuration | Vitest and Vite config integration, defineConfig usage | core-config |
| CLI | Command line interface, commands and options | core-cli |
| Test API | test/it function, modifiers like skip, only, concurrent | core-test-api |
| Describe API | describe/suite for grouping tests and nested suites | core-describe |
| Expect API | Assertions with toBe, toEqual, matchers and asymmetric matchers | core-expect |
| Hooks | beforeEach, afterEach, beforeAll, afterAll, aroundEach | core-hooks |
Features
| Topic | Description | Reference |
|---|---|---|
| Mocking | Mock functions, modules, timers, dates with vi utilities | features-mocking |
| Snapshots | Snapshot testing with toMatchSnapshot and inline snapshots | features-snapshots |
| Coverage | Code coverage with V8 or Istanbul providers | features-coverage |
| Test Context | Test fixtures, context.expect, test.extend for custom fixtures | features-context |
| Concurrency | Concurrent tests, parallel execution, sharding | features-concurrency |
| Filtering | Filter tests by name, file patterns, tags | features-filtering |
What ships with it
17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- GENERATION.md 136 B
- references/advanced-environments.md 3.9 KB
- references/advanced-projects.md 4.7 KB
- references/advanced-type-testing.md 4.5 KB
- references/advanced-vi.md 4.5 KB
- references/core-cli.md 3.3 KB
- references/core-config.md 3.3 KB
- references/core-describe.md 3.3 KB
- references/core-expect.md 4.5 KB
- references/core-hooks.md 4.3 KB
- references/core-test-api.md 3.9 KB
- references/features-concurrency.md 4.3 KB
- references/features-context.md 4.2 KB
- references/features-coverage.md 3.3 KB
- references/features-filtering.md 3.4 KB
- references/features-mocking.md 4.8 KB
- references/features-snapshots.md 3.7 KB
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 First seen · 53 lines · 36 tokens per session scan A 8366b304deb2
vitest is a skill published in the GitHub repository FranRom/pupila (36 stars, last pushed 2mo ago), licensed MIT. It adds 36 tokens to every session and 710 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to vitest, differing in 72 lines, and is treated as a copy.
Other skills, from other repositories
js-in-html-testing
Test JS logic embedded in HTML using two-layer strategy - Python unit tests + Playwright browser integration tests.
api-testing
Testing patterns for MCP tool/resource handlers using createMockContext and Vitest. Covers mock context options, handler testing, McpError assertions, format testing, Vitest config setup, and test isolation conventions.
testing
Use this skill when writing, reviewing, or improving tests in WrongStack. Triggers: user says "test", "unit test", "integration test", "e2e", "mock", "vitest", "coverage", "assert", "expect", "test strategy", "write tests".
test-generator
Generate test templates for unit tests, integration tests, and UI tests using Swift Testing and XCTest. Use when adding tests to iOS/macOS apps.
testing-flutter
Testing Flutter 3.44 / BLoC v9 / Riverpod 3 - Stratégie Complète. Use when writing tests, reviewing test coverage, or setting up testing.
backseat-driver-testing
Testing strategies for Calva Backseat Driver MCP tools. Use when: Testing Backseat Driver, validating tool updates, testing structural editing workflows, verifying REPL evaluation with who-tracking, testing shadow-cljs runtime discovery and targeting, testing output log filtering, testing load-file tool, smoke testing…