vitest-testing-expert

Replace jest.mock with vi.mock imported from 'vitest', update type imports from the Jest namespace, and enable globals: true for easier transition. Note that mockReset in Vitest restores the original implementation rather than returning an empty function.

Install @vitest/browser plus playwright or webdriverio, then enable browser mode in your config with instances specifying browsers like chromium. Import page and commands from '@vitest/browser/context' for DOM interactions.

Vitest integrates natively with Vite's configuration and transform pipeline, offering native ESM support and faster execution through dependency optimization. Jest requires separate transformation setup and lacks direct Vite integration.

Slow tests usually stem from suboptimal pool configuration, unnecessary isolation, or unoptimized dependencies. Try adjusting pool options, disabling isolation when tests lack side effects, and enabling deps.optimizer for web and ssr.

Yes, Vitest provides native ESM support without transformation overhead and built-in TypeScript handling. Add Vitest types to your tsconfig and use import.meta.vitest for in-source testing.

This error occurs when Jest API calls remain after migration. Replace jest.mock with vi.mock and import vi from 'vitest', since Vitest does not inject Jest globals by default.