Vitest
Vite-native test runner. Native ESM, ultra-fast watch mode, zero-config TypeScript. 534 tests on Coeurdar, mandatory CI gate.
Strengths
- Watch mode 5x faster than Jest, instant feedback during development
- Native ESM + zero-config TypeScript, no babel, no ts-jest
- Jest-compatible API (describe, it, expect), near-free migration
- Stable Browser Mode (v4), tests in real Chromium, Firefox, WebKit
Limitations
- Plugin ecosystem less mature than Jest, some community mocks missing
- Coupled to Vite, if your build doesn't use Vite, Jest is more natural
Best for
- Any Vite project, the natural pair, zero additional config
- Fast CI gates, tests run 5x faster than Jest