vitest

by antfu6.0k

Vitest fast unit testing framework powered by Vite with Jest-compatible API. Use when writing tests, mocking, configuring coverage, or working with test filtering and fixtures.

Install

The skill file stays in the publisher's repository.

Paste the copied command in a terminal. It installs this SKILL.md into that agent.

npx skills add antfu/skills --skill vitest -a cursor -y

Download skill skills/vitest/SKILL.md on GitHub

Related skills

View all

A
antfuAnthony Fu's opinionated tooling and conventions for JavaScript/TypeScript projects. Use when setting up new projects, configuring ESLint/Prettier alternatives, monorepos, library publishing, or when
N
nuxtNuxt full-stack Vue framework with SSR, auto-imports, and file-based routing. Use when working with Nuxt apps, server routes, useFetch, middleware, or hybrid rendering.
A
antfu-create-prCreate a reviewable GitHub pull request from the current branch with a Conventional Commits title, a concise evidence-based body, and before/after screenshots for UI changes. Use when asked to open, c

Questions

How do I install vitest?: Download skills/vitest/SKILL.md from the publisher, or copy the path and open the repository. PlugMCP lists the skill and does not host the file.
Where does vitest live?: The publisher keeps it at https://github.com/antfu/skills.
Which agents can use vitest?: Claude, Cursor, and Codex can read a SKILL.md you add from the publisher's repository.

name: vitest description: Vitest fast unit testing framework powered by Vite with Jest-compatible API. Use when writing tests, mocking, configuring coverage, or working with test filtering and fixtures. metadata: author: Anthony Fu version: "2026.9.25" source: Generated from https://github.com/vitest-dev/vitest, scripts located at https://github.com/antfu/skills

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

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

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
Test Tags	Label tests with tags to filter runs and apply shared options	features-test-tags
Reporters	Built-in reporters, default selection, CI/output config	features-reporters
Benchmarking	Write benchmarks with the bench fixture (Tinybench)	features-benchmarking

Topic	Description	Reference
Vi Utilities	vi helper: mock, spyOn, fake timers, hoisted, waitFor	advanced-vi
Environments	Test environments: node, jsdom, happy-dom, custom	advanced-environments
Type Testing	Type-level testing with expectTypeOf and assertType	advanced-type-testing
Projects	Multi-project workspaces, different configs per project	advanced-projects

vitest

Install

Related skills

Questions

Core

Features

Advanced