Vitest

   🐞 Bug Fixes

• browser: Check fs access in builtin commands [backport to v4] &nbsp;-&nbsp; by @hi-ogawa, Hiroshi Ogawa and OpenCode (claude-opus-4-8) in https://github.com/vitest-dev/vitest/issues/10680 <samp>(5c18d)</samp>
• vm: Fix external module resolve error with deps optimizer query for encoded URI [backport to v4] &nbsp;-&nbsp; by @SveLil and @hi-ogawa in https://github.com/vitest-dev/vitest/issues/10661 <samp>(bae52)</samp>

&nbsp;&nbsp;&nbsp;&nbsp;View changes on GitHub

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Vitest

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Next generation testing framework powered by Vite.

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<a href="https://npmx.dev/package/vitest"><img src="https://img.shields.io/npm/v/vitest?color=729B1B&label=" alt="current vitest version badge"></a>

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<a href="https://chat.vitest.dev"><b>Get involved!</b></a>

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<a href="https://vitest.dev">Documentation</a> | <a href="https://vitest.dev/guide/">Getting Started</a> | <a href="https://vitest.dev/guide/#examples">Examples</a> | <a href="https://vitest.dev/guide/why">Why Vitest?</a>

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<a href="https://cn.vitest.dev">中文文档</a>

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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

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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