vitest

Vitest is a next-generation testing framework powered by Vite, designed to provide a fast and modern testing experience. It leverages Vite's configuration, transformers, resolvers, and plugins, allowing you to use the same setup as your application. Key features include: - **Vite Integration**: Uses Vite's config, transformers, resolvers, and plugins for seamless integration. - **Jest Snapshot**: Supports Jest snapshot testing. - **Chai Built-in**: Includes Chai for assertions with Jest expect-compatible APIs. - **Smart & Instant Watch Mode**: Provides a watch mode similar to HMR for tests. - **Native Code Coverage**: Supports coverage via v8 or Istanbul. - **Jest-compatible Mocking**: Includes mocking, stubbing, and spies. - **DOM and Browser API Mocking**: Works with JSDOM and happy-dom. - **Browser Mode**: Run component tests in the browser for frameworks like Vue, React, Svelte, Lit, and Marko. - **Benchmarking**: Supports benchmarking with Tinybench. - **Projects Support**: Manage multiple projects. - **Type-level Testing**: Includes expect-type for type-level testing. - **ESM First**: Supports top-level await and ESM. - **TypeScript/JSX Support**: Out-of-box support. - **Filtering, Timeouts, Concurrent**: For suites and tests. - **Sharding Support**: Distribute tests across multiple processes. - **Uncaught Error Reporting**: Reports uncaught errors. - **Native Browser Testing**: Run tests in the browser natively. Vitest requires Vite >=v6.4.0 and Node >=v22.12.0. It is MIT licensed and maintained by VoidZero Inc. and contributors.