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 v8 or istanbul.

• Jest-compatible mocking, stubbing, and spies.

• JSDOM and happy-dom for DOM and browser API mocking

• Browser Mode for running component tests in the browser

• Components testing (Vue, React, Svelte, Lit, Marko)

• Benchmarking support with Tinybench

• Projects support

• 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

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()
  })
})

$ npx vitest

Sponsors

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!

Contribution

See Contributing Guide.

License

MIT License © 2021-Present VoidZero Inc. and Vitest contributors