Handle cross-page client reference contamination in development

packages/next/errors.json

@@ -947,5 +947,8 @@
   "946": "Failed to deserialize errors.",
   "947": "Expected `sendErrorsToBrowser` to be defined in renderOpts.",
   "948": "Failed to serialize errors.",
-  "949": "Route %s errored during %s. These errors are normally ignored and may not prevent the route from prerendering but are logged here because build debugging is enabled.\n          \nOriginal Error: %s"
+  "949": "Route %s errored during %s. These errors are normally ignored and may not prevent the route from prerendering but are logged here because build debugging is enabled.\n          \nOriginal Error: %s",
+  "950": "The manifests singleton was not initialized.",
+  "951": "The client reference manifest for route \"%s\" does not exist.",
+  "952": "Cannot access \"%s\" without a work store."
 }

packages/next/src/build/templates/app-page.ts

@@ -21,12 +21,11 @@ import {
   createOpaqueFallbackRouteParams,
   type OpaqueFallbackRouteParams,
 } from '../../server/request/fallback-params'
-import { setReferenceManifestsSingleton } from '../../server/app-render/encryption-utils'
+import { setManifestsSingleton } from '../../server/app-render/manifests-singleton'
 import {
   isHtmlBotRequest,
   shouldServeStreamingMetadata,
 } from '../../server/lib/streaming-metadata'
-import { createServerModuleMap } from '../../server/app-render/action-utils'
 import { normalizeAppPath } from '../../shared/lib/router/utils/app-paths'
 import { getIsPossibleServerAction } from '../../server/lib/server-action-request-meta'
 import {
@@ -400,13 +399,10 @@ export async function handler(
   // set the reference manifests to our global store so Server Action's
   // encryption util can access to them at the top level of the page module.
   if (serverActionsManifest && clientReferenceManifest) {
-    setReferenceManifestsSingleton({
+    setManifestsSingleton({
       page: srcPage,
       clientReferenceManifest,
       serverActionsManifest,
-      serverModuleMap: createServerModuleMap({
-        serverActionsManifest,
-      }),
     })
   }
 
@@ -540,8 +536,6 @@ export async function handler(
           nextFontManifest,
           reactLoadableManifest,
           subresourceIntegrityManifest,
-          serverActionsManifest,
-          clientReferenceManifest,
           setCacheStatus: routerServerContext?.setCacheStatus,
           setIsrStatus: routerServerContext?.setIsrStatus,
           setReactDebugChannel: routerServerContext?.setReactDebugChannel,

packages/next/src/build/templates/app-route.ts

@@ -8,8 +8,7 @@ import { patchFetch as _patchFetch } from '../../server/lib/patch-fetch'
 import type { IncomingMessage, ServerResponse } from 'node:http'
 import { addRequestMeta, getRequestMeta } from '../../server/request-meta'
 import { getTracer, type Span, SpanKind } from '../../server/lib/trace/tracer'
-import { setReferenceManifestsSingleton } from '../../server/app-render/encryption-utils'
-import { createServerModuleMap } from '../../server/app-render/action-utils'
+import { setManifestsSingleton } from '../../server/app-render/manifests-singleton'
 import { normalizeAppPath } from '../../shared/lib/router/utils/app-paths'
 import { NodeNextRequest, NodeNextResponse } from '../../server/base-http/node'
 import {
@@ -185,13 +184,10 @@ export async function handler(
   // set the reference manifests to our global store so Server Action's
   // encryption util can access to them at the top level of the page module.
   if (serverActionsManifest && clientReferenceManifest) {
-    setReferenceManifestsSingleton({
+    setManifestsSingleton({
       page: srcPage,
       clientReferenceManifest,
       serverActionsManifest,
-      serverModuleMap: createServerModuleMap({
-        serverActionsManifest,
-      }),
     })
   }
 

packages/next/src/build/templates/edge-app-route.ts

@@ -1,5 +1,4 @@
-import { createServerModuleMap } from '../../server/app-render/action-utils'
-import { setReferenceManifestsSingleton } from '../../server/app-render/encryption-utils'
+import { setManifestsSingleton } from '../../server/app-render/manifests-singleton'
 import type { NextConfigComplete } from '../../server/config-shared'
 import { EdgeRouteModuleWrapper } from '../../server/web/edge-route-module-wrapper'
 
@@ -16,13 +15,10 @@ const rscManifest = self.__RSC_MANIFEST?.['VAR_PAGE']
 const rscServerManifest = maybeJSONParse(self.__RSC_SERVER_MANIFEST)
 
 if (rscManifest && rscServerManifest) {
-  setReferenceManifestsSingleton({
+  setManifestsSingleton({
     page: 'VAR_PAGE',
     clientReferenceManifest: rscManifest,
     serverActionsManifest: rscServerManifest,
-    serverModuleMap: createServerModuleMap({
-      serverActionsManifest: rscServerManifest,
-    }),
   })
 }
 

packages/next/src/build/templates/edge-ssr-app.ts

@@ -6,8 +6,7 @@ import * as pageMod from 'VAR_USERLAND'
 
 import type { RequestData } from '../../server/web/types'
 import type { NextConfigComplete } from '../../server/config-shared'
-import { setReferenceManifestsSingleton } from '../../server/app-render/encryption-utils'
-import { createServerModuleMap } from '../../server/app-render/action-utils'
+import { setManifestsSingleton } from '../../server/app-render/manifests-singleton'
 import { initializeCacheHandlers } from '../../server/use-cache/handlers'
 import { BaseServerSpan } from '../../server/lib/trace/constants'
 import { getTracer, SpanKind, type Span } from '../../server/lib/trace/tracer'
@@ -40,13 +39,10 @@ const rscManifest = self.__RSC_MANIFEST?.['VAR_PAGE']
 const rscServerManifest = maybeJSONParse(self.__RSC_SERVER_MANIFEST)
 
 if (rscManifest && rscServerManifest) {
-  setReferenceManifestsSingleton({
+  setManifestsSingleton({
     page: 'VAR_PAGE',
     clientReferenceManifest: rscManifest,
     serverActionsManifest: rscServerManifest,
-    serverModuleMap: createServerModuleMap({
-      serverActionsManifest: rscServerManifest,
-    }),
   })
 }
 
@@ -81,12 +77,10 @@ async function requestHandler(
     buildManifest,
     prerenderManifest,
     reactLoadableManifest,
-    clientReferenceManifest,
     subresourceIntegrityManifest,
     dynamicCssManifest,
     nextFontManifest,
     resolvedPathname,
-    serverActionsManifest,
     interceptionRoutePatterns,
     routerServerContext,
   } = prepareResult
@@ -129,8 +123,6 @@ async function requestHandler(
       reactLoadableManifest,
       subresourceIntegrityManifest,
       dynamicCssManifest,
-      serverActionsManifest,
-      clientReferenceManifest,
       setIsrStatus: routerServerContext?.setIsrStatus,
 
       dir: pageRouteModule.relativeProjectDir,

packages/next/src/build/webpack/loaders/next-app-loader/index.ts

@@ -682,7 +682,14 @@ const nextAppLoader: AppLoader = async function nextAppLoader() {
 
   const buildInfo = getModuleBuildInfo((this as any)._module)
   const collectedDeclarations: [string, string][] = []
-  const page = name.replace(/^app/, '')
+
+  // Use the page from loaderOptions directly instead of deriving it from name.
+  // The name (bundlePath) may have been normalized with normalizePagePath()
+  // which is designed for Pages Router and incorrectly duplicates /index paths
+  // (e.g., /index/page -> /index/index/page). The page parameter contains the
+  // correct unnormalized value.
+  const page = loaderOptions.page
+
   const middlewareConfig: ProxyConfig = JSON.parse(
     Buffer.from(middlewareConfigBase64, 'base64').toString()
   )

packages/next/src/build/webpack/plugins/flight-manifest-plugin.ts

@@ -41,7 +41,7 @@ interface Options {
 type ModuleId = string | number /*| null*/
 
 // double indexed chunkId, filename
-export type ManifestChunks = Array<string>
+export type ManifestChunks = ReadonlyArray<string>
 
 const pluginState = getProxiedPluginState({
   ssrModules: {} as { [ssrModuleId: string]: ModuleInfo },

packages/next/src/export/index.ts

@@ -385,11 +385,6 @@ async function exportAppImpl(
       join(distDir, 'server', `${NEXT_FONT_MANIFEST}.json`)
     ),
     images: nextConfig.images,
-    ...(enabledDirectories.app
-      ? {
-          serverActionsManifest,
-        }
-      : {}),
     deploymentId: nextConfig.deploymentId,
     htmlLimitedBots: nextConfig.htmlLimitedBots.source,
     experimental: {

packages/next/src/server/app-render/action-handler.ts

@@ -49,7 +49,7 @@ import { warn } from '../../build/output/log'
 import { RequestCookies, ResponseCookies } from '../web/spec-extension/cookies'
 import { HeadersAdapter } from '../web/spec-extension/adapters/headers'
 import { fromNodeOutgoingHttpHeaders } from '../web/utils'
-import { selectWorkerForForwarding } from './action-utils'
+import { selectWorkerForForwarding, type ServerModuleMap } from './action-utils'
 import { isNodeNextRequest, isWebNextRequest } from '../base-http/helpers'
 import { RedirectStatusCode } from '../../client/components/redirect-status-code'
 import { synchronizeMutableCookies } from '../async-storage/request-store'
@@ -59,7 +59,7 @@ import { InvariantError } from '../../shared/lib/invariant-error'
 import { executeRevalidates } from '../revalidation-utils'
 import { getRequestMeta } from '../request-meta'
 import { setCacheBustingSearchParam } from '../../client/components/router-reducer/set-cache-busting-search-param'
-import { getServerModuleMap } from './encryption-utils'
+import { getServerModuleMap } from './manifests-singleton'
 
 function formDataFromSearchQueryString(query: string) {
   const searchParams = new URLSearchParams(query)
@@ -473,15 +473,6 @@ export function parseHostHeader(
       : undefined
 }
 
-type ServerModuleMap = Record<
-  string,
-  {
-    id: string
-    chunks: string[]
-    name: string
-  }
->
-
 type ServerActionsConfig = {
   bodySizeLimit?: SizeLimit
   allowedOrigins?: string[]
@@ -522,7 +513,7 @@ export async function handleAction({
   metadata: AppPageRenderResultMetadata
 }): Promise<HandleActionResult> {
   const contentType = req.headers['content-type']
-  const { serverActionsManifest, page } = ctx.renderOpts
+  const { page } = ctx.renderOpts
   const serverModuleMap = getServerModuleMap()
 
   const {
@@ -640,11 +631,7 @@ export async function handleAction({
   const actionWasForwarded = Boolean(req.headers['x-action-forwarded'])
 
   if (actionId) {
-    const forwardedWorker = selectWorkerForForwarding(
-      actionId,
-      page,
-      serverActionsManifest
-    )
+    const forwardedWorker = selectWorkerForForwarding(actionId, page)
 
     // If forwardedWorker is truthy, it means there isn't a worker for the action
     // in the current handler, so we forward the request to a worker that has the action.
@@ -685,7 +672,7 @@ export async function handleAction({
       { isAction: true },
       async (): Promise<HandleActionResult> => {
         // We only use these for fetch actions -- MPA actions handle them inside `decodeAction`.
-        let actionModId: string | undefined
+        let actionModId: string | number | undefined
         let boundActionArguments: unknown[] = []
 
         if (
@@ -1214,7 +1201,7 @@ async function executeActionAndPrepareForRender<
 function getActionModIdOrError(
   actionId: string | null,
   serverModuleMap: ServerModuleMap
-): string {
+): string | number {
   // if we're missing the action ID header, we can't do any further processing
   if (!actionId) {
     throw new InvariantError("Missing 'next-action' header.")

packages/next/src/server/app-render/action-utils.ts

@@ -2,8 +2,18 @@ import type { ActionManifest } from '../../build/webpack/plugins/flight-client-e
 import { normalizeAppPath } from '../../shared/lib/router/utils/app-paths'
 import { pathHasPrefix } from '../../shared/lib/router/utils/path-has-prefix'
 import { removePathPrefix } from '../../shared/lib/router/utils/remove-path-prefix'
+import { getServerActionsManifest } from './manifests-singleton'
 import { workAsyncStorage } from './work-async-storage.external'
 
+export interface ServerModuleMap {
+  readonly [name: string]: {
+    readonly id: string | number
+    readonly name: string
+    readonly chunks: Readonly<Array<string>> // currently not used
+    readonly async?: boolean
+  }
+}
+
 // This function creates a Flight-acceptable server module map proxy from our
 // Server Reference Manifest similar to our client module map.
 // This is because our manifest contains a lot of internal Next.js data that
@@ -12,7 +22,7 @@ export function createServerModuleMap({
   serverActionsManifest,
 }: {
   serverActionsManifest: ActionManifest
-}) {
+}): ServerModuleMap {
   return new Proxy(
     {},
     {
@@ -61,11 +71,8 @@ export function createServerModuleMap({
  * Checks if the requested action has a worker for the current page.
  * If not, it returns the first worker that has a handler for the action.
  */
-export function selectWorkerForForwarding(
-  actionId: string,
-  pageName: string,
-  serverActionsManifest: ActionManifest
-) {
+export function selectWorkerForForwarding(actionId: string, pageName: string) {
+  const serverActionsManifest = getServerActionsManifest()
   const workers =
     serverActionsManifest[
       process.env.NEXT_RUNTIME === 'edge' ? 'edge' : 'node'