Vitest
A blazing fast unit test framework powered by Vite.
> ⚠️ **DISCLAIMER**: Vitest is still in development and not stable yet. It's not recommended to use it in production.
> Vitest requires Vite v2.7 and Node v14
Follow the [Getting Started Guide](https://vitest.dev/guide) or learn [why we are building a new test runner](https://vitest.dev/guide/why).
## Documentation
Read the [documentation](https://vitest.dev/).
## 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](#watch-mode), like HMR for tests!
- [Native code coverage](#coverage) via [c8](https://github.com/bcoe/c8)
- [Tinyspy](https://github.com/Aslemammad/tinyspy) built-in for 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
- Components testing ([Vue](./test/vue), [React](./test/react), [Lit](./test/lit), [Vitesse](./test/vitesse))
- Workers multi-threading via [tinypool](https://github.com/Aslemammad/tinypool) (a lightweight fork of [Piscina](https://github.com/piscinajs/piscina))
- ESM first, top level await
- Out-of-box TypeScript / JSX support
- Filtering, timeouts, concurrent for suite and tests
```ts
import { it, describe, expect, assert } 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
```
## Examples
- [Unit Testing](./test/core)
- [Vue Component Testing](./test/vue)
- [React Component Testing](./test/react)
- [Lit Component Testing](./test/lit)
- [Vitesse Component Testing](./test/vitesse)
## Projects using Vitest
- [unocss](https://github.com/antfu/unocss)
- [unplugin-auto-import](https://github.com/antfu/unplugin-auto-import)
- [unplugin-vue-components](https://github.com/antfu/unplugin-vue-components)
- [vitesse-lite](https://github.com/antfu/vitesse-lite)
## Sponsors
### Anthony Fu Sponsors
### Patak Sponsors
## Credits
Thanks to:
- [The Jest team and community](https://jestjs.io/) for creating a delightful testing API
- [@lukeed](https://github.com/lukeed) for the work on [uvu](https://github.com/lukeed/uvu) where we are inspired a lot from.
- [@pi0](https://github.com/pi0) for the idea and implementation of using Vite to transform and bundle the server code.
- [The Vite team](https://github.com/vitejs/vite) for brainstorming the initial idea.
- [@patak-dev](https://github.com/patak-dev) for the awesome package name!
## License
[MIT](./LICENSE) License © 2021-Present [Anthony Fu](https://github.com/antfu), [Matias Capeletto](https://github.com/patak-dev)