Vitest Has a Free Testing Framework — Blazing-Fast Unit Tests for Vite Projects

Vitest is a Vite-native unit testing framework with Jest-compatible API. What You Get for Free Vite-powered — same config, transforms, and plugins as your app Jest-compatible — same API (describe, it, expect), easy migration TypeScript — first-class support, no setup needed ESM native — no CommonJS workarounds Watch mode — instant re-runs on file changes UI — visual test runner in browser Coverage — built-in c8/istanbul coverage Snapshot testing — inline and file snapshots Mocking — vi.mock, vi.fn, vi.spyOn Workspace — monorepo support Quick Start npm install -D vitest // sum.test.ts import { describe , it , expect } from ' vitest ' import { sum } from ' ./sum ' describe ( ' sum ' , () => { it ( ' adds numbers ' , () => { expect ( sum ( 1 , 2 )). toBe ( 3 ) }) }) // package.json { "scripts" : { "test" : "vitest" } } Why Developers Switch from Jest Jest is slow with ESM and TypeScript: 10-20x faster — Vite's transform pipeline is faster than ts-jest ESM native — no CJS/ESM headaches Sam