# Nuxt Runtime Environment

## Overview

The Nuxt test environment initializes a global Nuxt app before tests run, including plugins and `app.vue`. This gives tests access to auto-imports, composables, and injections.

Tests run in `happy-dom` (default) or `jsdom`. Be careful not to mutate global state, or reset it afterwards.

## Environment Separation

- **`test/unit/`** — Node environment, fast, no Nuxt runtime. For pure logic, utilities, helpers.
- **`test/nuxt/`** — Nuxt environment, has access to auto-imports, composables, plugins. For components and composables that depend on Nuxt.
- **`test/e2e/`** — Node environment, launches a full Nuxt server. For end-to-end testing.

**Important:** `@nuxt/test-utils/runtime` and `@nuxt/test-utils/e2e` cannot be used in the same file — they need different environments.

## Naming Convention for Mixed Setups

If using the simple (non-project) config, separate by file extension:

- `app.nuxt.spec.ts` — runs in Nuxt environment (uses `@nuxt/test-utils/runtime`)
- `app.e2e.spec.ts` — runs in Node environment (uses `@nuxt/test-utils/e2e`)

Or use per-file environment comments:

```ts
// @vitest-environment nuxt
```

## Environment Options

Configure in `vitest.config.ts`:

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

export default defineVitestConfig({
  test: {
    environmentOptions: {
      nuxt: {
        domEnvironment: 'happy-dom', // or 'jsdom'
        overrides: {
          // Nuxt config overrides for testing
        },
      },
    },
  },
})
```