vitest

vitest is a skill for Claude Code from HigorAlves/orc. It costs 36 tokens per session (750 once invoked), scanned A, a copy of vitest, MIT.

A JavaScript and TypeScript test framework designed to work closely with Vite, a frontend build tool. It provides familiar test commands plus support for mocks, coverage, snapshots, and browser-like code environments.

In plain words
What is it for?
It is for writing unit tests, checking test coverage, mocking dependencies, using fixtures, filtering tests, and testing TypeScript, JSX, or modern JavaScript modules.
Why use it?
It gives Vite projects one place to run unit tests and related checks without setting up a separate build and test pipeline.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the orc plugin — 84 skills, 31 commands, 14 agents, 6 hooks shipped together

Good fit It is for writing unit tests, checking test coverage, mocking dependencies, using fixtures, filtering tests, and testing TypeScript, JSX, or modern JavaScript modules.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/higoralves/orc/vitest
Install

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.

Any agent
npx skills add HigorAlves/orc --skill vitest
Clone the repo
git clone --depth 1 https://github.com/HigorAlves/orc

Made for: Claude Code.

Or install orc, the plugin that ships this one along with the rest of its 84 skills, 31 commands, 14 agents, 6 hooks.

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.

agentmods badge for vitest

README.md
[![agentmods](https://agentmods.dev/badge/skills/higoralves/orc/vitest/github.svg)](https://agentmods.dev/skills/higoralves/orc/vitest)
Your own site
<a href="https://agentmods.dev/skills/higoralves/orc/vitest"><img src="https://agentmods.dev/badge/skills/higoralves/orc/vitest/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.

agentmods 80×15 button for vitest

Your own site · 80×15
<a href="https://agentmods.dev/skills/higoralves/orc/vitest"><img src="https://agentmods.dev/badge/skills/higoralves/orc/vitest.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 750 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 94% copy Near-identical to another mod 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00036 $0.00750
Opus 5.5 $0.00014 $0.00300
Sonnet 5.5 $0.00007 $0.00150
Haiku 4.5 $0.00004 $0.00075

Measured 1mo ago against content hash bb9e8bf951d4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

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 1mo 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.

Origin

This is a copy

94% identical to vitest — 55 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.

orc/skills/vitest/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vitest is a next-generation testing framework powered by Vite. It provides a Jest-compatible API with native ESM, TypeScript, and JSX support out of the box. Vitest shares the same config, transformers, resolvers, and plugins with your Vite app.

Key Features:

  • Vite-native: Uses Vite's transformation pipeline for fast HMR-like test updates
  • Jest-compatible: Drop-in replacement for most Jest test suites
  • Smart watch mode: Only reruns affected tests based on module graph
  • Native ESM, TypeScript, JSX support without configuration
  • Multi-threaded workers for parallel test execution
  • Built-in coverage via V8 or Istanbul
  • Snapshot testing, mocking, and spy utilities

The skill is based on Vitest 3.x, generated at 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

Read the full file on GitHub · 54 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.

  1. 1mo ago First seen · 54 lines · 36 tokens per session scan A bb9e8bf951d4

Subscribe to this mod's changes

vitest is a skill published in the GitHub repository HigorAlves/orc (6 stars, last pushed 6d ago), licensed MIT. It adds 36 tokens to every session and 750 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 94% identical to vitest, differing in 55 lines, and is treated as a copy.