Nuxt/docs/content/2.guide/6.going-further/7.testing.md

# Testing

::alert{icon=👉}
Test utils are still in development and the API and behavior may change. Currently, it's for module authors to preview but not yet ready for testing production apps.
::

In Nuxt 3, we have a rewritten version of `@nuxt/test-utils` available as `@nuxt/test-utils-edge`. We support [Vitest](https://github.com/vitest-dev/vitest) and [Jest](https://jestjs.io/) as the test runner.

## Installation

```bash
yarn add --dev @nuxt/test-utils-edge vitest
```

## Setup

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

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

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.

## Options

### Nuxt Configuration

#### `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'`

<!--
#### config

Object with configuration overrides.

* Type: `NuxtConfig`
* Default: `{}` -->

### Setup 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 to Enable

#### `server`

Whether to launch a server to respond to requests in the test suite.

* Type: `boolean`
* Default: `true`

#### `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`](https://playwright.dev/) to carry out browser testing. If this option is set, a browser will be launched and can be controlled in the subsequent test suite. (More info can be found [here](/guide/going-further/testing).)

* 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](https://playwright.dev/#version=master&path=docs%2Fapi.md&q=browsertypelaunchoptions).

#### `runner`

Specify the runner for the test suite. Currently, [Vitest](https://vitest.dev/) is recommended.

* Type: `'vitest' | 'jest'`
* Default: `'vitest'`

## APIs

### APIs for Rendering Testing

#### `$fetch(url)`

Get the HTML of a server-rendered page.

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

const html = await $fetch('/')
```

#### `fetch(url)`

Get the response of a server-rendered page.

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

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.)

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

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

## Testing Modules

### Fixture Setup

To test the modules we create, we could set up some Nuxt apps as fixtures and test their behaviors. For example, we can create a simple Nuxt app under `./test/fixture` with the configuration like:

```ts
// nuxt.config.js
import { defineNuxtConfig } from 'nuxt'
import MyModule from '../../src'

export default defineNuxtConfig({
  modules: [
    MyModule
  ]
})
```

### Tests Setup

We can create a test file and use the `rootDir` to test the fixture.

```ts
// basic.test.js
import { describe, it, expect } from 'vitest'
import { fileURLToPath } from 'node:url'
import { setup, $fetch } from '@nuxt/test-utils-edge'

describe('ssr', async () => {
  await setup({
    rootDir: fileURLToPath(new URL('./fixture', import.meta.url)),
  })

  it('renders the index page', async () => {
    // Get response to a server-rendered page with `$fetch`.
    const html = await $fetch('/')

    expect(html).toContain('<a>A Link</a>')
  })
})
```

For more usage, please refer to our [tests for Nuxt 3 framework](https://github.com/nuxt/framework/blob/main/test/basic.test.ts).

## Mock utils

- `mockFn()`: Returns a mocked function based on test runner.
- `mockLogger()`: Mocks logger using [`consola.mockTypes`](https://github.com/unjs/consola#mocktypes) and `mockFn()`. Returns an object of mocked logger types.

## Testing in a Browser

::alert{icon=🚧}
We are working on it, stay tuned!
::