## Features
- [Vite](https://vitejs.dev/)'s config, transformers, resolvers, and plugins. Use the same setup from your app!
- [Jest Snapshot](https://jestjs.io/docs/snapshot-testing)
- [Chai](https://www.chaijs.com/) built-in for assertions, with [Jest expect](https://jestjs.io/docs/expect) compatible APIs
- [Smart & instant watch mode](https://vitest.dev/guide/features.html#watch-mode), like HMR for tests!
- [Native code coverage](https://vitest.dev/guide/features.html#coverage) via [`v8`](https://v8.dev/blog/javascript-code-coverage) or [`istanbul`](https://istanbul.js.org/).
- Jest-compatible mocking, stubbing, and spies.
- [JSDOM](https://github.com/jsdom/jsdom) and [happy-dom](https://github.com/capricorn86/happy-dom) for DOM and browser API mocking
- [Browser Mode](https://vitest.dev/guide/browser/) for running component tests in the browser
- Components testing ([Vue](https://github.com/vitest-tests/browser-examples/tree/main/examples/vue), [React](https://github.com/vitest-tests/browser-examples/tree/main/examples/react), [Svelte](https://github.com/vitest-tests/browser-examples/tree/main/examples/svelte), [Lit](./examples/lit), [Marko](https://github.com/marko-js/examples/tree/master/examples/library-ts))
- Benchmarking support with [Tinybench](https://github.com/tinylibs/tinybench)
- [Projects](https://vitest.dev/guide/projects) support
- [expect-type](https://github.com/mmkal/expect-type) for type-level testing
- ESM first, top level await
- Out-of-box TypeScript / JSX support
- Filtering, timeouts, concurrent for suite and tests
- Sharding support
- Reporting Uncaught Errors
- Run your tests in the browser natively
> Vitest requires Vite >=v6.4.0 and Node >=v22.12.0
```ts
import { assert, describe, expect, it } from 'vitest'
describe('suite name', () => {
it('foo', () => {
expect(1 + 1).toEqual(2)
expect(true).to.be.true
})
it('bar', () => {
assert.equal(Math.sqrt(4), 2)
})
it('snapshot', () => {
expect({ foo: 'bar' }).toMatchSnapshot()
})
})
```
```bash
$ npx vitest
```
## Sponsors
