Vitest

A blazing fast unit test framework powered by Vite.

Get involved!

⚠️ DISCLAIMER: Vitest is still in development and not stable yet. It's not recommended to use it in production.

Vitest requires Vite >=v2.7.10 and Node >=v14

Follow the Getting Started Guide or learn why we are building a new test runner.

Documentation

Read the documentation.

Examples | Projects using Vitest

Features

Vite's config, transformers, resolvers, and plugins. Use the same setup from your app!
Jest Snapshot
Chai built-in for assertions, with Jest expect compatible APIs.
Smart & instant watch mode, like HMR for tests!
Native code coverage via c8
Tinyspy built-in for mocking, stubbing, and spies.
JSDOM and happy-dom for DOM and browser API mocking
Components testing (Vue, React, Svelte, Lit, Vitesse)
Workers multi-threading via tinypool (a lightweight fork of Piscina)
ESM first, top level await
Out-of-box TypeScript / JSX support
Filtering, timeouts, concurrent for suite and tests

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()
  })
})

$ npx vitest

Credits

Thanks to:

The Jest team and community for creating a delightful testing API
@lukeed for the work on uvu where we are inspired a lot from.
@pi0 for the idea and implementation of using Vite to transform and bundle the server code.
The Vite team for brainstorming the initial idea.
@patak-dev for the awesome package name!

EvHaus/vitest

Vitest

Get involved!

Documentation

Features

Sponsors

Anthony Fu Sponsors

Patak Sponsors

Credits

License