Freeze loaded manifests (#64313)

Manifests in the runtime should be treated as immutable objects to
ensure that side effects aren't created that depend on the mutability of
these shared objects. Instead, mutable references should be used in
places where this is desirable.

This also introduces the new `DeepReadonly` utility type, which when
paired with existing manifest types, will modify every field to be read
only, ensuring that the type system will help catch accidental
modifications to these loaded manifest values as well.

Future work could eliminate these types by modifying the manifest types
themselves to be read only, only allowing code that generated them to be
writable.

Closes NEXT-3069

packages/next/src/build/index.ts

@@ -185,6 +185,7 @@ import { buildCustomRoute } from '../lib/build-custom-route'
 import { createProgress } from './progress'
 import { traceMemoryUsage } from '../lib/memory/trace'
 import { generateEncryptionKeyBase64 } from '../server/app-render/encryption-utils'
+import type { DeepReadonly } from '../shared/lib/deep-readonly'
 
 interface ExperimentalBypassForInfo {
   experimentalBypassFor?: RouteHas[]
@@ -337,27 +338,28 @@ async function readManifest<T extends object>(filePath: string): Promise<T> {
 
 async function writePrerenderManifest(
   distDir: string,
-  manifest: Readonly<PrerenderManifest>
+  manifest: DeepReadonly<PrerenderManifest>
 ): Promise<void> {
   await writeManifest(path.join(distDir, PRERENDER_MANIFEST), manifest)
   await writeEdgePartialPrerenderManifest(distDir, manifest)
 }
 
 async function writeEdgePartialPrerenderManifest(
   distDir: string,
-  manifest: Readonly<Partial<PrerenderManifest>>
+  manifest: DeepReadonly<Partial<PrerenderManifest>>
 ): Promise<void> {
   // We need to write a partial prerender manifest to make preview mode settings available in edge middleware.
   // Use env vars in JS bundle and inject the actual vars to edge manifest.
-  const edgePartialPrerenderManifest: Partial<PrerenderManifest> = {
-    ...manifest,
-    preview: {
-      previewModeId: 'process.env.__NEXT_PREVIEW_MODE_ID',
-      previewModeSigningKey: 'process.env.__NEXT_PREVIEW_MODE_SIGNING_KEY',
-      previewModeEncryptionKey:
-        'process.env.__NEXT_PREVIEW_MODE_ENCRYPTION_KEY',
-    },
-  }
+  const edgePartialPrerenderManifest: DeepReadonly<Partial<PrerenderManifest>> =
+    {
+      ...manifest,
+      preview: {
+        previewModeId: 'process.env.__NEXT_PREVIEW_MODE_ID',
+        previewModeSigningKey: 'process.env.__NEXT_PREVIEW_MODE_SIGNING_KEY',
+        previewModeEncryptionKey:
+          'process.env.__NEXT_PREVIEW_MODE_ENCRYPTION_KEY',
+      },
+    }
   await writeFileUtf8(
     path.join(distDir, PRERENDER_MANIFEST.replace(/\.json$/, '.js')),
     `self.__PRERENDER_MANIFEST=${JSON.stringify(
@@ -367,7 +369,7 @@ async function writeEdgePartialPrerenderManifest(
 }
 
 async function writeClientSsgManifest(
-  prerenderManifest: PrerenderManifest,
+  prerenderManifest: DeepReadonly<PrerenderManifest>,
   {
     buildId,
     distDir,
@@ -3318,7 +3320,7 @@ export default async function build(
         NextBuildContext.allowedRevalidateHeaderKeys =
           config.experimental.allowedRevalidateHeaderKeys
 
-        const prerenderManifest: Readonly<PrerenderManifest> = {
+        const prerenderManifest: DeepReadonly<PrerenderManifest> = {
           version: 4,
           routes: finalPrerenderRoutes,
           dynamicRoutes: finalDynamicRoutes,

packages/next/src/build/webpack/loaders/next-edge-ssr-loader/render.ts

@@ -19,6 +19,7 @@ import type { SizeLimit } from '../../../../../types'
 import { internal_getCurrentFunctionWaitUntil } from '../../../../server/web/internal-edge-wait-until'
 import type { PAGE_TYPES } from '../../../../lib/page-types'
 import type { NextRequestHint } from '../../../../server/web/adapter'
+import type { DeepReadonly } from '../../../../shared/lib/deep-readonly'
 
 export function getRender({
   dev,
@@ -53,7 +54,7 @@ export function getRender({
   renderToHTML?: any
   Document: DocumentType
   buildManifest: BuildManifest
-  prerenderManifest: PrerenderManifest
+  prerenderManifest: DeepReadonly<PrerenderManifest>
   reactLoadableManifest: ReactLoadableManifest
   subresourceIntegrityManifest?: Record<string, string>
   interceptionRouteRewrites?: ManifestRewriteRoute[]

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

@@ -70,7 +70,7 @@ export interface ManifestNode {
 }
 
 export type ClientReferenceManifest = {
-  moduleLoading: {
+  readonly moduleLoading: {
     prefix: string
     crossOrigin: string | null
   }

packages/next/src/client/components/request-async-storage.external.ts

@@ -5,13 +5,16 @@ import type { ReadonlyHeaders } from '../../server/web/spec-extension/adapters/h
 import type { ReadonlyRequestCookies } from '../../server/web/spec-extension/adapters/request-cookies'
 
 import { createAsyncLocalStorage } from './async-local-storage'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 export interface RequestStore {
   readonly headers: ReadonlyHeaders
   readonly cookies: ReadonlyRequestCookies
   readonly mutableCookies: ResponseCookies
   readonly draftMode: DraftModeProvider
-  readonly reactLoadableManifest: Record<string, { files: string[] }>
+  readonly reactLoadableManifest: DeepReadonly<
+    Record<string, { files: string[] }>
+  >
   readonly assetPrefix: string
 }
 

packages/next/src/export/index.ts

@@ -56,6 +56,7 @@ import { formatManifest } from '../build/manifests/formatter/format-manifest'
 import { validateRevalidate } from '../server/lib/patch-fetch'
 import { TurborepoAccessTraceResult } from '../build/turborepo-access-trace'
 import { createProgress } from '../build/progress'
+import type { DeepReadonly } from '../shared/lib/deep-readonly'
 
 export class ExportError extends Error {
   code = 'NEXT_EXPORT_ERROR'
@@ -188,7 +189,7 @@ export async function exportAppImpl(
     !options.pages &&
     (require(join(distDir, SERVER_DIRECTORY, PAGES_MANIFEST)) as PagesManifest)
 
-  let prerenderManifest: PrerenderManifest | undefined
+  let prerenderManifest: DeepReadonly<PrerenderManifest> | undefined
   try {
     prerenderManifest = require(join(distDir, PRERENDER_MANIFEST))
   } catch {}

packages/next/src/pages/_document.tsx

@@ -25,6 +25,7 @@ import {
 } from '../shared/lib/html-context.shared-runtime'
 import type { HtmlProps } from '../shared/lib/html-context.shared-runtime'
 import { encodeURIPath } from '../shared/lib/encode-uri-path'
+import type { DeepReadonly } from '../shared/lib/deep-readonly'
 
 export type { DocumentContext, DocumentInitialProps, DocumentProps }
 
@@ -360,7 +361,7 @@ function getAmpPath(ampPath: string, asPath: string): string {
 }
 
 function getNextFontLinkTags(
-  nextFontManifest: NextFontManifest | undefined,
+  nextFontManifest: DeepReadonly<NextFontManifest> | undefined,
   dangerousAsPath: string,
   assetPrefix: string = ''
 ) {

packages/next/src/server/app-render/app-render.tsx

@@ -107,6 +107,7 @@ import {
   wrapClientComponentLoader,
 } from '../client-component-renderer-logger'
 import { createServerModuleMap } from './action-utils'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 export type GetDynamicParamFromSegment = (
   // [slug] / [[slug]] / [...slug]
@@ -137,7 +138,7 @@ export type AppRenderContext = AppRenderBaseContext & {
   requestId: string
   defaultRevalidate: Revalidate
   pagePath: string
-  clientReferenceManifest: ClientReferenceManifest
+  clientReferenceManifest: DeepReadonly<ClientReferenceManifest>
   assetPrefix: string
   flightDataRendererErrorHandler: ErrorHandler
   serverComponentsErrorHandler: ErrorHandler

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

@@ -1,5 +1,6 @@
 import type { ActionManifest } from '../../build/webpack/plugins/flight-client-entry-plugin'
 import type { ClientReferenceManifest } from '../../build/webpack/plugins/flight-manifest-plugin'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 // Keep the key in memory as it should never change during the lifetime of the server in
 // both development and production.
@@ -116,8 +117,8 @@ export function setReferenceManifestsSingleton({
   serverActionsManifest,
   serverModuleMap,
 }: {
-  clientReferenceManifest: ClientReferenceManifest
-  serverActionsManifest: ActionManifest
+  clientReferenceManifest: DeepReadonly<ClientReferenceManifest>
+  serverActionsManifest: DeepReadonly<ActionManifest>
   serverModuleMap: {
     [id: string]: {
       id: string
@@ -160,8 +161,8 @@ export function getClientReferenceManifestSingleton() {
   const serverActionsManifestSingleton = (globalThis as any)[
     SERVER_ACTION_MANIFESTS_SINGLETON
   ] as {
-    clientReferenceManifest: ClientReferenceManifest
-    serverActionsManifest: ActionManifest
+    clientReferenceManifest: DeepReadonly<ClientReferenceManifest>
+    serverActionsManifest: DeepReadonly<ActionManifest>
   }
 
   if (!serverActionsManifestSingleton) {
@@ -181,8 +182,8 @@ export async function getActionEncryptionKey() {
   const serverActionsManifestSingleton = (globalThis as any)[
     SERVER_ACTION_MANIFESTS_SINGLETON
   ] as {
-    clientReferenceManifest: ClientReferenceManifest
-    serverActionsManifest: ActionManifest
+    clientReferenceManifest: DeepReadonly<ClientReferenceManifest>
+    serverActionsManifest: DeepReadonly<ActionManifest>
   }
 
   if (!serverActionsManifestSingleton) {

packages/next/src/server/app-render/get-css-inlined-link-tags.tsx

@@ -1,10 +1,11 @@
 import type { ClientReferenceManifest } from '../../build/webpack/plugins/flight-manifest-plugin'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 /**
  * Get external stylesheet link hrefs based on server CSS manifest.
  */
 export function getLinkAndScriptTags(
-  clientReferenceManifest: ClientReferenceManifest,
+  clientReferenceManifest: DeepReadonly<ClientReferenceManifest>,
   filePath: string,
   injectedCSS: Set<string>,
   injectedScripts: Set<string>,

packages/next/src/server/app-render/get-preloadable-fonts.tsx

@@ -1,4 +1,5 @@
 import type { NextFontManifest } from '../../build/webpack/plugins/next-font-manifest-plugin'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 /**
  * Get hrefs for fonts to preload
@@ -8,7 +9,7 @@ import type { NextFontManifest } from '../../build/webpack/plugins/next-font-man
  * Returns null if there are fonts but none to preload and at least some were previously preloaded
  */
 export function getPreloadableFonts(
-  nextFontManifest: NextFontManifest | undefined,
+  nextFontManifest: DeepReadonly<NextFontManifest> | undefined,
   filePath: string | undefined,
   injectedFontPreloadTags: Set<string>
 ): string[] | null {

packages/next/src/server/app-render/types.ts

@@ -7,6 +7,7 @@ import type { ParsedUrlQuery } from 'querystring'
 import type { AppPageModule } from '../future/route-modules/app-page/module'
 import type { SwrDelta } from '../lib/revalidate'
 import type { LoadingModuleData } from '../../shared/lib/app-router-context.shared-runtime'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 import s from 'next/dist/compiled/superstruct'
 
@@ -126,14 +127,14 @@ export interface RenderOptsPartial {
   buildId: string
   basePath: string
   trailingSlash: boolean
-  clientReferenceManifest?: ClientReferenceManifest
+  clientReferenceManifest?: DeepReadonly<ClientReferenceManifest>
   supportsDynamicHTML: boolean
   runtime?: ServerRuntime
   serverComponents?: boolean
   enableTainting?: boolean
   assetPrefix?: string
   crossOrigin?: '' | 'anonymous' | 'use-credentials' | undefined
-  nextFontManifest?: NextFontManifest
+  nextFontManifest?: DeepReadonly<NextFontManifest>
   isBot?: boolean
   incrementalCache?: import('../lib/incremental-cache').IncrementalCache
   isRevalidate?: boolean

packages/next/src/server/app-render/use-flight-response.tsx

@@ -2,6 +2,7 @@ import type { ClientReferenceManifest } from '../../build/webpack/plugins/flight
 import type { BinaryStreamOf } from './app-render'
 
 import { htmlEscapeJsonString } from '../htmlescape'
+import type { DeepReadonly } from '../../shared/lib/deep-readonly'
 
 const isEdgeRuntime = process.env.NEXT_RUNTIME === 'edge'
 
@@ -18,7 +19,7 @@ const encoder = new TextEncoder()
  */
 export function useFlightStream<T>(
   flightStream: BinaryStreamOf<T>,
-  clientReferenceManifest: ClientReferenceManifest,
+  clientReferenceManifest: DeepReadonly<ClientReferenceManifest>,
   nonce?: string
 ): Promise<T> {
   const response = flightResponses.get(flightStream)

packages/next/src/server/base-server.ts

@@ -135,6 +135,7 @@ import { NextDataPathnameNormalizer } from './future/normalizers/request/next-da
 import { getIsServerAction } from './lib/server-action-request-meta'
 import { isInterceptionRouteAppPath } from './future/helpers/interception-routes'
 import { toRoute } from './lib/to-route'
+import type { DeepReadonly } from '../shared/lib/deep-readonly'
 
 export type FindComponentsResult = {
   components: LoadComponentsReturnType
@@ -285,9 +286,9 @@ export default abstract class Server<ServerOptions extends Options = Options> {
   protected readonly renderOpts: BaseRenderOpts
   protected readonly serverOptions: Readonly<ServerOptions>
   protected readonly appPathRoutes?: Record<string, string[]>
-  protected readonly clientReferenceManifest?: ClientReferenceManifest
+  protected readonly clientReferenceManifest?: DeepReadonly<ClientReferenceManifest>
   protected interceptionRoutePatterns: RegExp[]
-  protected nextFontManifest?: NextFontManifest
+  protected nextFontManifest?: DeepReadonly<NextFontManifest>
   private readonly responseCache: ResponseCacheBase
 
   protected abstract getPublicDir(): string
@@ -314,9 +315,11 @@ export default abstract class Server<ServerOptions extends Options = Options> {
     shouldEnsure?: boolean
     url?: string
   }): Promise<FindComponentsResult | null>
-  protected abstract getFontManifest(): FontManifest | undefined
-  protected abstract getPrerenderManifest(): PrerenderManifest
-  protected abstract getNextFontManifest(): NextFontManifest | undefined
+  protected abstract getFontManifest(): DeepReadonly<FontManifest> | undefined
+  protected abstract getPrerenderManifest(): DeepReadonly<PrerenderManifest>
+  protected abstract getNextFontManifest():
+    | DeepReadonly<NextFontManifest>
+    | undefined
   protected abstract attachRequestMeta(
     req: BaseNextRequest,
     parsedUrl: NextUrlWithParsedQuery

packages/next/src/server/future/route-modules/app-route/module.ts

@@ -4,6 +4,7 @@ import type { AppConfig } from '../../../../build/utils'
 import type { NextRequest } from '../../../web/spec-extension/request'
 import type { PrerenderManifest } from '../../../../build'
 import type { NextURL } from '../../../web/next-url'
+import type { DeepReadonly } from '../../../../shared/lib/deep-readonly'
 
 import {
   RouteModule,
@@ -63,7 +64,7 @@ export type AppRouteModule =
  */
 export interface AppRouteRouteHandlerContext extends RouteModuleHandleContext {
   renderOpts: StaticGenerationContext['renderOpts']
-  prerenderManifest: PrerenderManifest
+  prerenderManifest: DeepReadonly<PrerenderManifest>
 }
 
 /**

packages/next/src/server/lib/incremental-cache/index.ts

@@ -7,6 +7,7 @@ import type {
   IncrementalCacheKindHint,
 } from '../../response-cache'
 import type { Revalidate } from '../revalidate'
+import type { DeepReadonly } from '../../../shared/lib/deep-readonly'
 
 import FetchCache from './fetch-cache'
 import FileSystemCache from './file-system-cache'
@@ -67,7 +68,7 @@ export class IncrementalCache implements IncrementalCacheType {
   readonly disableForTestmode?: boolean
   readonly cacheHandler?: CacheHandler
   readonly hasCustomCacheHandler: boolean
-  readonly prerenderManifest: PrerenderManifest
+  readonly prerenderManifest: DeepReadonly<PrerenderManifest>
   readonly requestHeaders: Record<string, undefined | string | string[]>
   readonly requestProtocol?: 'http' | 'https'
   readonly allowedRevalidateHeaderKeys?: string[]
@@ -115,7 +116,7 @@ export class IncrementalCache implements IncrementalCacheType {
     allowedRevalidateHeaderKeys?: string[]
     requestHeaders: IncrementalCache['requestHeaders']
     maxMemoryCacheSize?: number
-    getPrerenderManifest: () => PrerenderManifest
+    getPrerenderManifest: () => DeepReadonly<PrerenderManifest>
     fetchCacheKeyPrefix?: string
     CurCacheHandler?: typeof CacheHandler
     experimental: { ppr: boolean }

packages/next/src/server/lib/incremental-cache/shared-revalidate-timings.ts

@@ -1,4 +1,5 @@
 import type { PrerenderManifest } from '../../../build'
+import type { DeepReadonly } from '../../../shared/lib/deep-readonly'
 import type { Revalidate } from '../revalidate'
 
 /**
@@ -18,7 +19,9 @@ export class SharedRevalidateTimings {
      * The prerender manifest that contains the initial revalidate timings for
      * routes.
      */
-    private readonly prerenderManifest: Pick<PrerenderManifest, 'routes'>
+    private readonly prerenderManifest: DeepReadonly<
+      Pick<PrerenderManifest, 'routes'>
+    >
   ) {}
 
   /**