vitest

Runs Jest-compatible unit and integration tests for Vite projects with TypeScript support.

2|Updated Feb 16, 2026
One-click install
npx skills add https://github.com/d0whc3r/statsig-browser-extension --skill vitest-d0whc3r
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: vitest
Source: https://github.com/d0whc3r/statsig-browser-extension/tree/main/.agents/skills/vitest
Command: npx skills add https://github.com/d0whc3r/statsig-browser-extension --skill vitest-d0whc3r

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Vitest solves the problem of slow and cumbersome unit/integration testing by providing a Jest-compatible test runner that integrates with Vite for fast feedback during development and CI.

Core Features & Use Cases

  • Vite-native execution: Leverages Vite’s transform pipeline for rapid reruns and consistent module handling.
  • Jest-compatible API: Use familiar test/expect patterns with native ESM, TypeScript, and JSX support.
  • Test performance & tooling: Provides watch mode re-running affected tests, parallel execution via workers, and built-in coverage (V8/Istanbul).
  • Common scenarios: Write and organize tests with describe suites and lifecycle hooks, mock dependencies with vi, and validate outputs with snapshots and assertions.
  • When to use: Choose Vitest for projects already using Vite, for TypeScript-first codebases, and when you need quick, maintainable tests with modern ESM support.

Quick Start

Use the vitest skill to run Jest-style unit tests for your Vite/TypeScript project and get deterministic assertions with expect.

Frequently Asked Questions about vitest

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I run unit tests for a Vite project with TypeScript and ESM support?▼

Vitest enables fast unit testing for Vite projects by providing a Jest-compatible runner with native ESM and TypeScript support. It leverages the Vite transform pipeline for rapid reruns and consistent module handling.

Can I use Jest-compatible assertions and mocking in Vitest?▼

Yes, Vitest offers a Jest-compatible API utilizing familiar `test` and `expect` patterns. It allows you to mock dependencies using the `vi` object and validate outputs using built-in assertions and snapshots.

What is the best way to get code coverage in a Vite test environment?▼

The best way to get code coverage in a Vite test environment is using Vitest's built-in coverage tooling. It supports V8 and Istanbul coverage providers and integrates directly into the test runner execution workflow.

Does Vitest support parallel execution and watch mode for test suites?▼

Yes, Vitest supports parallel execution via workers and includes a watch mode that re-runs only affected tests. These features ensure quick feedback during development and continuous integration.

How do I configure a test runner using defineConfig for modern Vite projects?▼

You can configure Vitest for modern Vite projects by integrating settings via `defineConfig`. This supports environment selection, fixtures/context extensions, and sharded runs to tailor the test execution workflow.