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Getting Started

Overview

Vitest is a blazing fast unit test framework powered by Vite.

You can learn more about the rationale behind the project in the Why Vitest section.

Trying Vitest Online

You can try Vitest online on StackBlitz. It runs Vitest directly in the browser, and it is almost identical to the local setup but doesn't require installing anything on your machine.

Adding Vitest to your Project

With npm

bash
npm install -D vitest
npm install -D vitest

or with yarn

bash
yarn add -D vitest
yarn add -D vitest

or with pnpm

bash
pnpm add -D vitest
pnpm add -D vitest

TIP

Vitest requires Vite >=v3.0.0 and Node >=v14

Configuring Vitest

One of the main advantages of Vitest is its unified configuration with Vite. If present, vitest will read your root vite.config.ts to match with the plugins and setup as your Vite app. For example, your Vite resolve.alias and plugins configuration will work out-of-the-box. If you want a different configuration during testing, you can:

  • Create vitest.config.ts, which will have the higher priority
  • Pass --config option to CLI, e.g. vitest --config ./path/to/vitest.config.ts
  • Use process.env.VITEST or mode property on defineConfig (will be set to test if not overridden) to conditionally apply different configuration in vite.config.ts

To configure vitest itself, add test property in your Vite config. You'll also need to add a reference to Vitest types using a triple slash command at the top of your config file, if you are importing defineConfig from vite itself.

ts
import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    // ...
  },
})
import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    // ...
  },
})

See the list of config options in the Config Reference

Command Line Interface

In a project where Vitest is installed, you can use the vitest binary in your npm scripts, or run it directly with npx vitest. Here are the default npm scripts in a scaffolded Vitest project:

json
{
  "scripts": {
    "test": "vitest",
    "coverage": "vitest run --coverage"
  }
}
{
  "scripts": {
    "test": "vitest",
    "coverage": "vitest run --coverage"
  }
}

To run tests once without watching for file changes, use vitest run. You can specify additional CLI options like --port or --https. For a full list of CLI options, run npx vitest --help in your project.

Learn more about the Command Line Interface

IDE Integrations

We also provided a official extension for Visual Studio Code to enhance your testing experience with Vitest.

Install from VS Code Marketplace

Learn more about IDE Integrations

Examples

ExampleSourcePlayground
basicGitHubPlay Online
fastifyGitHubPlay Online
graphqlGitHubPlay Online
litGitHubPlay Online
mocksGitHubPlay Online
nextjsGitHubPlay Online
playwrightGitHub
puppeteerGitHub
react-enzymeGitHubPlay Online
react-muiGitHubPlay Online
react-storybookGitHubPlay Online
react-testing-lib-mswGitHubPlay Online
react-testing-libGitHubPlay Online
reactGitHubPlay Online
rubyGitHubPlay Online
solidGitHubPlay Online
svelteGitHubPlay Online
vitesseGitHubPlay Online
vue-jsxGitHubPlay Online
vueGitHubPlay Online
vue2GitHubPlay Online

Projects using Vitest

Using Unreleased Commits

If you can't wait for a new release to test the latest features, you will need to clone the vitest repo to your local machine and then build and link it yourself (pnpm is required):

bash
git clone https://github.com/vitest-dev/vitest.git
cd vitest
pnpm install
cd packages/vitest
pnpm run build
pnpm link --global # you can use your preferred package manager for this step
git clone https://github.com/vitest-dev/vitest.git
cd vitest
pnpm install
cd packages/vitest
pnpm run build
pnpm link --global # you can use your preferred package manager for this step

Then go to the project where you are using Vitest and run pnpm link --global vitest (or the package manager that you used to link vitest globally).

Community

If you have questions or need help, reach out to the community at Discord and GitHub Discussions.

Released under the MIT License.