feat(kit,nuxt): allow multiple nuxts to run in one process (#30510)

packages/kit/src/context.ts

@@ -1,9 +1,22 @@
-import { getContext } from 'unctx'
+import { AsyncLocalStorage } from 'node:async_hooks'
+import { createContext, getContext } from 'unctx'
 import type { Nuxt } from '@nuxt/schema'
 
-/** Direct access to the Nuxt context - see https://github.com/unjs/unctx. */
+/**
+ * Direct access to the Nuxt global context - see https://github.com/unjs/unctx.
+ * @deprecated Use `getNuxtCtx` instead
+ */
 export const nuxtCtx = getContext<Nuxt>('nuxt')
 
+/** async local storage for the name of the current nuxt instance */
+const asyncNuxtStorage = createContext<Nuxt>({
+  asyncContext: true,
+  AsyncLocalStorage,
+})
+
+/** Direct access to the Nuxt context with asyncLocalStorage - see https://github.com/unjs/unctx. */
+export const getNuxtCtx = () => asyncNuxtStorage.tryUse()
+
 // TODO: Use use/tryUse from unctx. https://github.com/unjs/unctx/issues/6
 
 /**
@@ -16,7 +29,7 @@ export const nuxtCtx = getContext<Nuxt>('nuxt')
  * ```
  */
 export function useNuxt (): Nuxt {
-  const instance = nuxtCtx.tryUse()
+  const instance = asyncNuxtStorage.tryUse() || nuxtCtx.tryUse()
   if (!instance) {
     throw new Error('Nuxt instance is unavailable!')
   }
@@ -36,5 +49,9 @@ export function useNuxt (): Nuxt {
  * ```
  */
 export function tryUseNuxt (): Nuxt | null {
-  return nuxtCtx.tryUse()
+  return asyncNuxtStorage.tryUse() || nuxtCtx.tryUse()
+}
+
+export function runWithNuxtContext<T extends (...args: any[]) => any> (nuxt: Nuxt, fn: T) {
+  return asyncNuxtStorage.call(nuxt, fn) as ReturnType<T>
 }

packages/kit/src/index.ts

@@ -18,7 +18,7 @@ export type { ExtendConfigOptions, ExtendViteConfigOptions, ExtendWebpackConfigO
 export { assertNuxtCompatibility, checkNuxtCompatibility, getNuxtVersion, hasNuxtCompatibility, isNuxtMajorVersion, normalizeSemanticVersion, isNuxt2, isNuxt3 } from './compatibility'
 export { addComponent, addComponentsDir } from './components'
 export type { AddComponentOptions } from './components'
-export { nuxtCtx, tryUseNuxt, useNuxt } from './context'
+export { getNuxtCtx, runWithNuxtContext, tryUseNuxt, useNuxt, nuxtCtx } from './context'
 export { createIsIgnored, isIgnored, resolveIgnorePatterns } from './ignore'
 export { addLayout } from './layout'
 export { addRouteMiddleware, extendPages, extendRouteRules } from './pages'

packages/kit/src/loader/nuxt.ts

@@ -2,6 +2,7 @@ import { pathToFileURL } from 'node:url'
 import { readPackageJSON, resolvePackageJSON } from 'pkg-types'
 import type { Nuxt } from '@nuxt/schema'
 import { importModule, tryImportModule } from '../internal/esm'
+import { runWithNuxtContext } from '../context'
 import type { LoadNuxtConfigOptions } from './config'
 
 export interface LoadNuxtOptions extends LoadNuxtConfigOptions {
@@ -76,10 +77,10 @@ export async function buildNuxt (nuxt: Nuxt): Promise<any> {
   // Nuxt 3
   if (nuxt.options._majorVersion === 3) {
     const { build } = await tryImportModule<typeof import('nuxt')>('nuxt-nightly', { paths: rootDir }) || await tryImportModule<typeof import('nuxt')>('nuxt3', { paths: rootDir }) || await importModule<typeof import('nuxt')>('nuxt', { paths: rootDir })
-    return build(nuxt)
+    return runWithNuxtContext(nuxt, () => build(nuxt))
   }
 
   // Nuxt 2
   const { build } = await tryImportModule<{ build: any }>('nuxt-edge', { paths: rootDir }) || await importModule<{ build: any }>('nuxt', { paths: rootDir })
-  return build(nuxt)
+  return runWithNuxtContext(nuxt, () => build(nuxt))
 }

packages/nuxt/src/core/nuxt.ts

@@ -1,11 +1,12 @@
 import { existsSync } from 'node:fs'
 import { rm } from 'node:fs/promises'
+import { randomUUID } from 'node:crypto'
 import { AsyncLocalStorage } from 'node:async_hooks'
 import { join, normalize, relative, resolve } from 'pathe'
 import { createDebugger, createHooks } from 'hookable'
 import ignore from 'ignore'
 import type { LoadNuxtOptions } from '@nuxt/kit'
-import { addBuildPlugin, addComponent, addPlugin, addPluginTemplate, addRouteMiddleware, addServerPlugin, addTypeTemplate, addVitePlugin, addWebpackPlugin, installModule, loadNuxtConfig, nuxtCtx, resolveAlias, resolveFiles, resolveIgnorePatterns, resolvePath, tryResolveModule, useNitro } from '@nuxt/kit'
+import { addBuildPlugin, addComponent, addPlugin, addPluginTemplate, addRouteMiddleware, addServerPlugin, addTypeTemplate, addVitePlugin, addWebpackPlugin, installModule, loadNuxtConfig, nuxtCtx, resolveAlias, resolveFiles, resolveIgnorePatterns, resolvePath, runWithNuxtContext, tryResolveModule, useNitro } from '@nuxt/kit'
 import type { Nuxt, NuxtHooks, NuxtModule, NuxtOptions } from 'nuxt/schema'
 import type { PackageJson } from 'pkg-types'
 import { readPackageJSON } from 'pkg-types'
@@ -52,17 +53,24 @@ import { VirtualFSPlugin } from './plugins/virtual'
 export function createNuxt (options: NuxtOptions): Nuxt {
   const hooks = createHooks<NuxtHooks>()
 
+  const { callHook, callHookParallel, callHookWith } = hooks
+  hooks.callHook = (...args) => runWithNuxtContext(nuxt, () => callHook(...args))
+  hooks.callHookParallel = (...args) => runWithNuxtContext(nuxt, () => callHookParallel(...args))
+  hooks.callHookWith = (...args) => runWithNuxtContext(nuxt, () => callHookWith(...args))
+
   const nuxt: Nuxt = {
+    __name: randomUUID(),
     _version: version,
     _asyncLocalStorageModule: options.experimental.debugModuleMutation ? new AsyncLocalStorage() : undefined,
     hooks,
     callHook: hooks.callHook,
     addHooks: hooks.addHooks,
     hook: hooks.hook,
-    ready: () => initNuxt(nuxt),
+    ready: () => runWithNuxtContext(nuxt, () => initNuxt(nuxt)),
     close: () => hooks.callHook('close', nuxt),
     vfs: {},
     apps: {},
+    runWithContext: fn => runWithNuxtContext(nuxt, fn),
     options,
   }
 
@@ -114,6 +122,14 @@ export function createNuxt (options: NuxtOptions): Nuxt {
     })
   }
 
+  if (!nuxtCtx.tryUse()) {
+    // backward compatibility with 3.x
+    nuxtCtx.set(nuxt)
+    nuxt.hook('close', () => {
+      nuxtCtx.unset()
+    })
+  }
+
   hooks.hookOnce('close', () => { hooks.removeAllHooks() })
 
   return nuxt
@@ -221,11 +237,6 @@ async function initNuxt (nuxt: Nuxt) {
       }
     }
   })
-
-  // Set nuxt instance for useNuxt
-  nuxtCtx.set(nuxt)
-  nuxt.hook('close', () => nuxtCtx.unset())
-
   const coreTypePackages = nuxt.options.typescript.hoist || []
 
   // Disable environment types entirely if `typescript.builder` is false
@@ -860,27 +871,29 @@ export async function loadNuxt (opts: LoadNuxtOptions): Promise<Nuxt> {
 
   const nuxt = createNuxt(options)
 
-  if (nuxt.options.dev && !nuxt.options.test) {
-    nuxt.hooks.hookOnce('build:done', () => {
-      for (const dep of keyDependencies) {
-        checkDependencyVersion(dep, nuxt._version)
-          .catch(e => logger.warn(`Problem checking \`${dep}\` version.`, e))
-      }
-    })
-  }
+  nuxt.runWithContext(() => {
+    if (nuxt.options.dev && !nuxt.options.test) {
+      nuxt.hooks.hookOnce('build:done', () => {
+        for (const dep of keyDependencies) {
+          checkDependencyVersion(dep, nuxt._version)
+            .catch(e => logger.warn(`Problem checking \`${dep}\` version.`, e))
+        }
+      })
+    }
 
-  // We register hooks layer-by-layer so any overrides need to be registered separately
-  if (opts.overrides?.hooks) {
-    nuxt.hooks.addHooks(opts.overrides.hooks)
-  }
+    // We register hooks layer-by-layer so any overrides need to be registered separately
+    if (opts.overrides?.hooks) {
+      nuxt.hooks.addHooks(opts.overrides.hooks)
+    }
 
-  if (
-    nuxt.options.debug
-    && nuxt.options.debug.hooks
-    && (nuxt.options.debug.hooks === true || nuxt.options.debug.hooks.server)
-  ) {
-    createDebugger(nuxt.hooks, { tag: 'nuxt' })
-  }
+    if (
+      nuxt.options.debug
+      && nuxt.options.debug.hooks
+      && (nuxt.options.debug.hooks === true || nuxt.options.debug.hooks.server)
+    ) {
+      createDebugger(nuxt.hooks, { tag: 'nuxt' })
+    }
+  })
 
   if (opts.ready !== false) {
     await nuxt.ready()

packages/nuxt/test/load-nuxt.test.ts

@@ -1,7 +1,8 @@
 import { fileURLToPath } from 'node:url'
-import { afterEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { normalize } from 'pathe'
 import { withoutTrailingSlash } from 'ufo'
+import { logger, tryUseNuxt, useNuxt } from '@nuxt/kit'
 import { loadNuxt } from '../src'
 
 const repoRoot = withoutTrailingSlash(normalize(fileURLToPath(new URL('../../../', import.meta.url))))
@@ -12,6 +13,7 @@ vi.stubGlobal('console', {
   warn: vi.fn(console.warn),
 })
 
+const loggerWarn = vi.spyOn(logger, 'warn')
 vi.mock('pkg-types', async (og) => {
   const originalPkgTypes = (await og<typeof import('pkg-types')>())
   return {
@@ -20,6 +22,9 @@ vi.mock('pkg-types', async (og) => {
   }
 })
 
+beforeEach(() => {
+  loggerWarn.mockClear()
+})
 afterEach(() => {
   vi.clearAllMocks()
 })
@@ -41,4 +46,41 @@ describe('loadNuxt', () => {
     await nuxt.close()
     expect(hookRan).toBe(true)
   })
+  it('load multiple nuxt', async () => {
+    await Promise.all([
+      loadNuxt({
+        cwd: repoRoot,
+      }),
+      loadNuxt({
+        cwd: repoRoot,
+      }),
+    ])
+    expect(loggerWarn).not.toHaveBeenCalled()
+  })
+
+  it('expect hooks to get the correct context outside of initNuxt', async () => {
+    const nuxt = await loadNuxt({
+      cwd: repoRoot,
+    })
+
+    // @ts-expect-error - random hook
+    nuxt.hook('test', () => {
+      expect(useNuxt().__name).toBe(nuxt.__name)
+    })
+
+    expect(tryUseNuxt()?.__name).not.toBe(nuxt.__name)
+
+    // second nuxt context
+    const second = await loadNuxt({
+      cwd: repoRoot,
+    })
+
+    expect(second.__name).not.toBe(nuxt.__name)
+    expect(tryUseNuxt()?.__name).not.toBe(nuxt.__name)
+
+    // @ts-expect-error - random hook
+    await nuxt.callHook('test')
+
+    expect(loggerWarn).not.toHaveBeenCalled()
+  })
 })

packages/schema/src/types/nuxt.ts

@@ -83,6 +83,7 @@ export interface NuxtApp {
 
 export interface Nuxt {
   // Private fields.
+  __name: string
   _version: string
   _ignore?: Ignore
   _dependencies?: Set<string>
@@ -96,6 +97,7 @@ export interface Nuxt {
   hook: Nuxt['hooks']['hook']
   callHook: Nuxt['hooks']['callHook']
   addHooks: Nuxt['hooks']['addHooks']
+  runWithContext: <T extends (...args: any[]) => any>(fn: T) => ReturnType<T>
 
   ready: () => Promise<void>
   close: () => Promise<void>