Testing · Get Started with Nuxt

If you are a module author, you can find more specific information in the Module Author's guide.

Nuxt offers first-class support for end-to-end and unit testing of your Nuxt application via @nuxt/test-utils, a library of test utilities and configuration that currently powers the tests we use on Nuxt itself and tests throughout the module ecosystem.

Watch a video from Alexander Lichter about getting started with the @nuxt/test-utils.

Installation

In order to allow you to manage your other testing dependencies, @nuxt/test-utils ships with various optional peer dependencies. For example:

you can choose between happy-dom and jsdom for a runtime Nuxt environment
you can choose between vitest, cucumber, jest and playwright for end-to-end test runners
playwright-core is only required if you wish to use the built-in browser testing utilities (and are not using @playwright/test as your test runner)

yarn add --dev @nuxt/test-utils vitest @vue/test-utils happy-dom playwright-core

Unit Testing

We currently ship an environment for unit testing code that needs a Nuxt runtime environment. It currently only has support for vitest (although contribution to add other runtimes would be welcome).

Setup

Add @nuxt/test-utils/module to your nuxt.config file (optional). It adds a Vitest integration to your Nuxt DevTools which supports running your unit tests in development.
```
export default defineNuxtConfig
({
  modules
: [
    '@nuxt/test-utils/module'
  ]
})
```

Create a vitest.config.ts with the following content:

import { defineVitestConfig
 } from '@nuxt/test-utils/config'

export default defineVitestConfig
({
  // any custom Vitest config you require
})

When importing @nuxt/test-utils in your vitest config, It is necessary to have "type": "module" specified in your package.json or rename your vitest config file appropriately.

ie. vitest.config.m{ts,js}.

Using a Nuxt Runtime Environment

By default, @nuxt/test-utils will not change your default Vitest environment, so you can do fine-grained opt-in and run Nuxt tests together with other unit tests.

You can opt in to a Nuxt environment by adding .nuxt. to the test file's name (for example, my-file.nuxt.test.ts or my-file.nuxt.spec.ts) or by adding @vitest-environment nuxt as a comment directly in the test file.

// @vitest-environment nuxt
import { test
 } from 'vitest'

test
('my test', () => {
  // ... test with Nuxt environment!
})

You can alternatively set environment: 'nuxt' in your Vitest configuration to enable the Nuxt environment for all tests.

// vitest.config.ts
import { fileURLToPath
 } from 'node:url'
import { defineVitestConfig
 } from '@nuxt/test-utils/config'

export default defineVitestConfig
({
  test
: {
    environment
: 'nuxt',
    // you can optionally set Nuxt-specific environment options
    // environmentOptions: {
    //   nuxt: {
    //     rootDir: fileURLToPath(new URL('./playground', import.meta.url)),
    //     domEnvironment: 'happy-dom', // 'happy-dom' (default) or 'jsdom'
    //     overrides: {
    //       // other Nuxt config you want to pass
    //     }
    //   }
    // }
  }
})

If you have set environment: 'nuxt' by default, you can then opt out of the default environment per test file as needed.

// @vitest-environment node
import { test
 } from 'vitest'

test
('my test', () => {
  // ... test without Nuxt environment!
})

When you run your tests within the Nuxt environment, they will be running in a happy-dom or jsdom environment. Before your tests run, a global Nuxt app will be initialized (including, for example, running any plugins or code you've defined in your app.vue).This means you should take particular care not to mutate the global state in your tests (or, if you need to, to reset it afterwards).

🎭 Built-In Mocks

@nuxt/test-utils provides some built-in mocks for the DOM environment.

`intersectionObserver`

Default true, creates a dummy class without any functionality for the IntersectionObserver API

`indexedDB`

Default false, uses fake-indexeddb to create a functional mock of the IndexedDB API

These can be configured in the environmentOptions section of your vitest.config.ts file:

import { defineVitestConfig
 } from '@nuxt/test-utils/config'

export default defineVitestConfig
({
  test
: {
    environmentOptions
: {
      nuxt
: {
        mock
: {
          intersectionObserver
: true,
          indexedDb
: true,
        }
      }
    }
  }
})

🛠️ Helpers

@nuxt/test-utils provides a number of helpers to make testing Nuxt apps easier.

`mountSuspended`

mountSuspended allows you to mount any Vue component within the Nuxt environment, allowing async setup and access to injections from your Nuxt plugins. For example:

// tests/components/SomeComponents.nuxt.spec.ts
import { mountSuspended
 } from '@nuxt/test-utils/runtime'
import { SomeComponent
 } from '#components'

it
('can mount some component', async () => {
    const component
 = await mountSuspended
(SomeComponent
)
    expect
(component
.text
()).toMatchInlineSnapshot
(
        '"This is an auto-imported component"'
    )
})

import { it, expect } from 'vitest'
// ---cut---
// tests/components/SomeComponents.nuxt.spec.ts
import { mountSuspended } from '@nuxt/test-utils/runtime'
import App from '~/app.vue'

// tests/App.nuxt.spec.ts
it('can also mount an app', async () => {
    const component = await mountSuspended(App, { route: '/test' })
    expect(component.html()).toMatchInlineSnapshot(`
      "<div>This is an auto-imported component</div>
      <div> I am a global component </div>
      <div>/</div>
      <a href="/test"> Test link </a>"
    `)
})

`renderSuspended`

renderSuspended allows you to render any Vue component within the Nuxt environment using @testing-library/vue, allowing async setup and access to injections from your Nuxt plugins.

This should be used together with utilities from Testing Library, e.g. screen and fireEvent. Install @testing-library/vue in your project to use these. Additionally, Testing Library also relies on testing globals for cleanup. You should turn these on in your Vitest config.

The passed in component will be rendered inside a <div id="test-wrapper"></div>.

Examples:

// tests/components/SomeComponents.nuxt.spec.ts
import { renderSuspended
 } from '@nuxt/test-utils/runtime'
import { SomeComponent
 } from '#components'
import { screen
 } from '@testing-library/vue'

it
('can render some component', async () => {
  await renderSuspended
(SomeComponent
)
  expect
(screen
.getByText
('This is an auto-imported component')).toBeDefined
()
})

import { it, expect } from 'vitest'
// ---cut---
// tests/App.nuxt.spec.ts
import { renderSuspended } from '@nuxt/test-utils/runtime'
import App from '~/app.vue'

it('can also render an app', async () => {
  const html = await renderSuspended(App, { route: '/test' })
  expect(html).toMatchInlineSnapshot(`
    "<div id="test-wrapper">
      <div>This is an auto-imported component</div>
      <div> I am a global component </div>
      <div>Index page</div><a href="/test"> Test link </a>
    </div>"
  `)
})

`mockNuxtImport`

mockNuxtImport allows you to mock Nuxt's auto import functionality. For example, to mock useStorage, you can do so like this:

import { mockNuxtImport
 } from '@nuxt/test-utils/runtime'

mockNuxtImport
('useStorage', () => {
  return () => {
    return { value
: 'mocked storage' }
  }
})

// your tests here

Note: mockNuxtImport can only be used once per mocked import per test file. It is actually a macro that gets transformed to vi.mock and vi.mock is hoisted, as described here.

If you need to mock a Nuxt import and provide different implementations between tests, you can do it by creating and exposing your mocks using vi.hoisted, and then use those mocks in mockNuxtImport. You then have access to the mocked imports, and can change the implementation between tests. Be careful to restore mocks before or after each test to undo mock state changes between runs.

import { vi
 } from 'vitest'
import { mockNuxtImport
 } from '@nuxt/test-utils/runtime'

const { useStorageMock
 } = vi
.hoisted
(() => {
  return {
    useStorageMock
: vi
.fn
().mockImplementation
(() => {
      return { value
: 'mocked storage'}
    })
  }
})

mockNuxtImport
('useStorage', () => {
  return useStorageMock
})

// Then, inside a test
useStorageMock
.mockImplementation
(() => {
  return { value
: 'something else' }
})

`mockComponent`

mockComponent allows you to mock Nuxt's component. The first argument can be the component name in PascalCase, or the relative path of the component. The second argument is a factory function that returns the mocked component.

For example, to mock MyComponent, you can:

import { mockComponent } from '@nuxt/test-utils/runtime'

mockComponent('MyComponent', {
  props: {
    value: String
  },
  setup(props) {
    // ...
  }
})

// relative path or alias also works
mockComponent('~/components/my-component.vue', async () => {
  // or a factory function
  return defineComponent({
    setup(props) {
      // ...
    }
  })
})

// or you can use SFC for redirecting to a mock component
mockComponent('MyComponent', () => import('./MockComponent.vue'))

// your tests here

Note: You can't reference local variables in the factory function since they are hoisted. If you need to access Vue APIs or other variables, you need to import them in your factory function.

import { mockComponent
 } from '@nuxt/test-utils/runtime'

mockComponent
('MyComponent', async () => {
  const { ref
, h
 } = await import('vue')

  return defineComponent
({
    setup
(props
) {
      const counter
 = ref
(0)
      return () => h
('div', null, counter
.value
)
    }
  })
})

`registerEndpoint`

registerEndpoint allows you create Nitro endpoint that returns mocked data. It can come in handy if you want to test a component that makes requests to API to display some data.

The first argument is the endpoint name (e.g. /test/). The second argument is a factory function that returns the mocked data.

For example, to mock /test/ endpoint, you can do:

import { registerEndpoint
 } from '@nuxt/test-utils/runtime'

registerEndpoint
('/test/', () => ({
  test
: 'test-field'
}))

By default, your request will be made using the GET method. You may use another method by setting an object as the second argument instead of a function.

import { registerEndpoint
 } from '@nuxt/test-utils/runtime'

registerEndpoint
('/test/', {
  method
: 'POST',
  handler
: () => ({ test
: 'test-field' })
})

Note: If your requests in a component go to external API, you can use baseURL and then make it empty using Nuxt Environment Config ($test) so all your requests will go to Nitro server.

Conflict with End-To-End Testing

@nuxt/test-utils/runtime and @nuxt/test-utils/e2e need to run in different testing environments and so can't be used in the same file.

If you would like to use both the end-to-end and unit testing functionality of @nuxt/test-utils, you can split your tests into separate files. You then either specify a test environment per-file with the special // @vitest-environment nuxt comment, or name your runtime unit test files with the .nuxt.spec.ts extension.

app.nuxt.spec.ts

import { mockNuxtImport
 } from '@nuxt/test-utils/runtime'

mockNuxtImport
('useStorage', () => {
  return () => {
    return { value
: 'mocked storage' }
  }
})

app.e2e.spec.ts

import { setup
, $fetch
 } from '@nuxt/test-utils/e2e'

await setup
({
  setupTimeout
: 10000,
})

// ...

Using `@vue/test-utils`

If you prefer to use @vue/test-utils on its own for unit testing in Nuxt, and you are only testing components which do not rely on Nuxt composables, auto-imports or context, you can follow these steps to set it up.

Install the needed dependencies

yarn add --dev vitest @vue/test-utils happy-dom @vitejs/plugin-vue

Create a vitest.config.ts with the following content:

import { defineConfig
 } from 'vitest/config'
import vue
 from '@vitejs/plugin-vue'

export default defineConfig
({
  plugins
: [vue
()],
  test
: {
    environment
: 'happy-dom',
  },
});

Add a new command for test in your package.json

"scripts": {
  "build": "nuxt build",
  "dev": "nuxt dev",
  ...
  "test": "vitest"
},

Create a simple <HelloWorld> component components/HelloWorld.vue with the following content:
```
<template>
  <p>Hello world</p>
</template>
```

Create a simple unit test for this newly created component ~/components/HelloWorld.spec.ts

import { describe, it, expect } from 'vitest'
import { mount } from '@vue/test-utils'

import HelloWorld from './HelloWorld.vue'

describe('HelloWorld', () => {
  it('component renders Hello world properly', () => {
    const wrapper = mount(HelloWorld)
    expect(wrapper.text()).toContain('Hello world')
  })
})

Run vitest command
```
yarn test
```

Congratulations, you're all set to start unit testing with @vue/test-utils in Nuxt! Happy testing!

End-To-End Testing

For end-to-end testing, we support Vitest, Jest, Cucumber and Playwright as test runners.

Setup

In each describe block where you are taking advantage of the @nuxt/test-utils/e2e helper methods, you will need to set up the test context before beginning.

test/my-test.spec.ts

import { describe
, test
 } from 'vitest'
import { setup
, $fetch
 } from '@nuxt/test-utils/e2e'

describe
('My test', async () => {
  await setup
({
    // test context options
  })

  test
('my test', () => {
    // ...
  })
})

Behind the scenes, setup performs a number of tasks in beforeAll, beforeEach, afterEach and afterAll to set up the Nuxt test environment correctly.

Please use the options below for the setup method.

Nuxt Config

rootDir: Path to a directory with a Nuxt app to be put under test.
- Type: string
- Default: '.'
configFile: Name of the configuration file.
- Type: string
- Default: 'nuxt.config'

Timings

setupTimeout: The amount of time (in milliseconds) to allow for setupTest to complete its work (which could include building or generating files for a Nuxt application, depending on the options that are passed).
- Type: number
- Default: 60000

Features

server: Whether to launch a server to respond to requests in the test suite.
- Type: boolean
- Default: true
port: If provided, set the launched test server port to the value.
- Type: number | undefined
- Default: undefined
build: Whether to run a separate build step.
- Type: boolean
- Default: true (false if browser or server is disabled)
browser: Under the hood, Nuxt test utils uses playwright to carry out browser testing. If this option is set, a browser will be launched and can be controlled in the subsequent test suite.
- Type: boolean
- Default: false
browserOptions
- Type: object with the following properties
  - type: The type of browser to launch - either chromium, firefox or webkit
  - launch: object of options that will be passed to playwright when launching the browser. See full API reference.
runner: Specify the runner for the test suite. Currently, Vitest is recommended.
- Type: 'vitest' | 'jest' | 'cucumber'
- Default: 'vitest'

APIs

`$fetch(url)`

Get the HTML of a server-rendered page.

import { $fetch
 } from '@nuxt/test-utils/e2e'

const html
 = await $fetch
('/')

`fetch(url)`

Get the response of a server-rendered page.

import { fetch
 } from '@nuxt/test-utils/e2e'

const res
 = await fetch
('/')
const { body
, headers
 } = res

`url(path)`

Get the full URL for a given page (including the port the test server is running on.)

import { url
 } from '@nuxt/test-utils/e2e'

const pageUrl
 = url
('/page')
// 'http://localhost:6840/page'

Testing in a Browser

We provide built-in support using Playwright within @nuxt/test-utils, either programmatically or via the Playwright test runner.

`createPage(url)`

Within vitest, jest or cucumber, you can create a configured Playwright browser instance with createPage, and (optionally) point it at a path from the running server. You can find out more about the API methods available from in the Playwright documentation.

import { createPage
 } from '@nuxt/test-utils/e2e'

const page
 = await createPage
('/page')
// you can access all the Playwright APIs from the `page` variable

Testing with Playwright Test Runner

We also provide first-class support for testing Nuxt within the Playwright test runner.

yarn add --dev @playwright/test @nuxt/test-utils

You can provide global Nuxt configuration, with the same configuration details as the setup() function mentioned earlier in this section.

playwright.config.ts

import { fileURLToPath } from 'node:url'
import { defineConfig, devices } from '@playwright/test'
import type { ConfigOptions } from '@nuxt/test-utils/playwright'

export default defineConfig<ConfigOptions>({
  use: {
    nuxt: {
      rootDir: fileURLToPath(new URL('.', import.meta.url))
    }
  },
  // ...
})