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by Maxonmax/nuxt-skills715 stars
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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.

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Use this Skill: https://skilld.dev/gh/onmax/nuxt-skills/vitest

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SKILL.md

≈46 tokens always: the name and description. ≈1.1k when used: this file. ≈23k more on demand in 19 files.

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 5.x (beta), generated at 2026-06-22.

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
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

Advanced

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

Source: SKILL.md on GitHub

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  • Gen Agent Trust Hub9d

    The skill is a comprehensive documentation set for the Vitest testing framework, providing configuration examples, API references, and CLI usage. No security issues were identified.

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    No alerts

  • Snyk9d

    Risk: LOW · No issues

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    Score: 93/100 · 2 sections analyzed

Provenance

Signed by skilld at de09c7b. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub 2 days ago.

Activeupdated last week

Capability

Other metadata
metadata
{
  "author": "Anthony Fu",
  "version": "2026.6.22",
  "source": "Generated from https://github.com/vitest-dev/vitest, scripts located at https://github.com/antfu/skills"
}

Topics

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What it does

Configures and runs Vitest for unit and integration testing in Vite projects, with Jest-compatible syntax for writing test suites, mocking modules and timers, and executing tests in parallel. Use this when setting up test infrastructure for Vue, React, or Svelte components, or when writing type tests with TypeScript.

Generated from the current SKILL.md.

Frequently asked

Does Vitest work with Vue, React, and Svelte components?
Yes. Vitest can test components from Vue, React, and Svelte. For component-specific patterns, the skill references a separate `vue` skill.
What environments does Vitest support for testing?
Vitest supports `node` and `jsdom` environments by default, with additional options for browser mode and type testing covered in the advanced reference.
Can I use Jest syntax with Vitest?
Yes. Vitest has a Jest-compatible API, so you can use familiar patterns like describe, it, expect, vi.fn, and vi.mock without syntax changes.
Does this skill cover mocking and test fixtures?
Yes. The skill includes reference files for mocking modules and timers with vi.fn and vi.mock, as well as test hooks and fixtures.

Generated from the current SKILL.md. These answers refresh after source changes.