---
name: projects-workspaces
description: Multi-project configuration for monorepos and different test types
---

# Projects

Run different test configurations in the same Vitest process.

## v5 Config Inheritance & Nested Projects

- **Inline projects inherit the root config by default** — `extends` now defaults to `true`, so root Vite options (`plugins`, `resolve.alias`) and test options are inherited. Arrays like `setupFiles` are appended, not replaced. Opt out with `extends: false`, or inherit from another file with `extends: './vitest.shared.ts'`. Projects referenced as config files/directories still don't inherit the root.
- **Referenced config files can declare their own `projects`** — such a config acts as a container providing *nested projects* named `app (unit)`, `app (e2e)`, etc. In v4 a referenced config's `projects` field was silently ignored, so audit merged configs that pull one in.
- **Inline projects share the declaring config's Vite server by default** ([`sharedViteServer`](core-config.md)) — the declaring config runs once, so plugin `config` hooks no longer run per project. A project gets its own server only when it changes the Vite config (`plugins`, `alias`, `css`, `deps.optimizer`, `root`, `browser`, `mode`). Set `sharedViteServer: false` if a plugin must be re-instantiated per project.

```ts
import { defineConfig } from 'vitest/config'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()], // inherited by every inline project (v4 needed extends: true)
  test: {
    projects: [
      { test: { name: 'unit', include: ['**/*.unit.test.ts'] } },
      // a package that declares its own projects becomes a nested container:
      './packages/app/vitest.config.ts', // -> "app (unit)", "app (e2e)", ...
    ],
  },
})
```

## Basic Projects Setup

```ts
// vitest.config.ts
defineConfig({
  test: {
    projects: [
      // Glob patterns for config files
      'packages/*',
      
      // Inline config
      {
        test: {
          name: 'unit',
          include: ['tests/unit/**/*.test.ts'],
          environment: 'node',
        },
      },
      {
        test: {
          name: 'integration',
          include: ['tests/integration/**/*.test.ts'],
          environment: 'jsdom',
        },
      },
    ],
  },
})
```

## Monorepo Pattern

```ts
defineConfig({
  test: {
    projects: [
      // Each package has its own vitest.config.ts
      'packages/core',
      'packages/cli',
      'packages/utils',
    ],
  },
})
```

Package config:

```ts
// packages/core/vitest.config.ts
import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    name: 'core',
    include: ['src/**/*.test.ts'],
    environment: 'node',
  },
})
```

## Different Environments

Run same tests in different environments:

```ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'happy-dom',
          root: './shared-tests',
          environment: 'happy-dom',
          setupFiles: ['./setup.happy-dom.ts'],
        },
      },
      {
        test: {
          name: 'node',
          root: './shared-tests',
          environment: 'node',
          setupFiles: ['./setup.node.ts'],
        },
      },
    ],
  },
})
```

## Browser + Node Projects

```ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'unit',
          include: ['tests/unit/**/*.test.ts'],
          environment: 'node',
        },
      },
      {
        test: {
          name: 'browser',
          include: ['tests/browser/**/*.test.ts'],
          browser: {
            enabled: true,
            name: 'chromium',
            provider: 'playwright',
          },
        },
      },
    ],
  },
})
```

## Shared Configuration

```ts
// vitest.shared.ts
export const sharedConfig = {
  testTimeout: 10000,
  setupFiles: ['./tests/setup.ts'],
}

// vitest.config.ts
import { sharedConfig } from './vitest.shared'

defineConfig({
  test: {
    projects: [
      {
        test: {
          ...sharedConfig,
          name: 'unit',
          include: ['tests/unit/**/*.test.ts'],
        },
      },
      {
        test: {
          ...sharedConfig,
          name: 'e2e',
          include: ['tests/e2e/**/*.test.ts'],
        },
      },
    ],
  },
})
```

## Project-Specific Dependencies

Each project can have different dependencies inlined:

```ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'project-a',
          server: {
            deps: {
              inline: ['package-a'],
            },
          },
        },
      },
    ],
  },
})
```

## Running Specific Projects

```bash
# Run specific project (v5 adds the -p shorthand)
vitest --project unit
vitest -p integration

# Multiple projects / wildcards
vitest --project unit --project e2e
vitest --project="packages*"

# Exclude a project
vitest --project="!browser"

# Nested projects: --project matches the prefix
vitest -p app                 # every project of the "app" config
vitest -p "app (unit)"        # just one nested project
```

## Providing Values to Projects

Share values from config to tests:

```ts
// vitest.config.ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'staging',
          provide: {
            apiUrl: 'https://staging.api.com',
            debug: true,
          },
        },
      },
      {
        test: {
          name: 'production',
          provide: {
            apiUrl: 'https://api.com',
            debug: false,
          },
        },
      },
    ],
  },
})

// In tests, use inject
import { inject } from 'vitest'

test('uses correct api', () => {
  const url = inject('apiUrl')
  expect(url).toContain('api.com')
})
```

## With Fixtures

```ts
const test = base.extend({
  apiUrl: ['/default', { injected: true }],
})

test('uses injected url', ({ apiUrl }) => {
  // apiUrl comes from project's provide config
})
```

## Per-Project Pool & Isolation (v4)

Since the v4 pool rework, isolation, parallelism, and Node CLI options can be set **per project**:

```ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'unit',
          isolate: false,                 // fast, non-isolated unit tests
          exclude: ['**/*.integration.test.ts'],
        },
      },
      {
        test: {
          name: 'sequential',
          include: ['**/*.sequential.test.ts'],
          fileParallelism: false,         // run these files one at a time
        },
      },
      {
        test: {
          name: 'staging',
          execArgv: ['--env-file=.env.staging'], // per-project Node flags
        },
      },
    ],
  },
})
```

## Global Setup per Project

```ts
defineConfig({
  test: {
    projects: [
      {
        test: {
          name: 'with-db',
          globalSetup: ['./tests/db-setup.ts'],
        },
      },
    ],
  },
})
```

## Key Points

- Projects run in same Vitest process (replaces the removed `workspace` option)
- Each project can have different environment, pool, isolation, and config
- Use glob patterns for monorepo packages
- Run specific projects with `--project` (supports wildcards and `!` exclusion)
- Use `provide` to inject config values into tests
- Inline projects inherit root config by default (v5 `extends: true`); set `extends: false` to opt out
- Referenced configs that declare `projects` provide nested projects (`name (child)`)

<!-- 
Source references:
- https://vitest.dev/guide/projects.html
-->