Vitest

Vite-native testing framework with Jest-compatible API.

When to Use

• Writing unit/integration tests for Vite projects

• Testing Vue/React/Svelte components

• Mocking modules, timers, or dates

• Running concurrent/parallel tests

• Type testing with TypeScript

Quick Start

npm i -D vitest

// vitest.config.ts import { defineConfig } from 'vitest/config'

export default defineConfig({ test: { globals: true, environment: 'node', // or 'jsdom' for DOM tests }, })

// example.test.ts import { describe, expect, it, vi } from 'vitest'

describe('math', () => { it('adds numbers', () => { expect(1 + 1).toBe(2) }) })

Reference Files

Task File

Configuration, CLI, projects config.md

test/describe, hooks, fixtures test-api.md

vi.fn, vi.mock, timers, spies mocking.md

expect, snapshots, coverage, filtering utilities.md

Environments, type testing, browser mode advanced.md

Loading Files

Consider loading these reference files based on your task:

• references/config.md - if setting up vitest.config.ts, CLI, or workspace projects

• references/test-api.md - if writing test/describe blocks, using hooks, or test fixtures

• references/mocking.md - if mocking modules, timers, dates, or using spies

• references/utilities.md - if writing assertions, snapshots, or configuring coverage

• references/advanced.md - if configuring test environments, type testing, or browser mode

DO NOT load all files at once. Load only what's relevant to your current task.

Cross-Skill References

• Vue component testing → Use vue skill for component patterns

• Library testing → Use ts-library skill for library patterns

• Vite configuration → Use vite skill for shared config