fix: marked all manifests that are loaded as frozen

packages/next/src/server/lib/freeze.ts

@@ -0,0 +1,34 @@
+/**
+ * Recursively freezes an object and all of its properties. This prevents the
+ * object from being modified at runtime. When the JS runtime is running in
+ * strict mode, any attempts to modify a frozen object will throw an error.
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze
+ * @param obj The object to freeze.
+ */
+export function freeze(obj: object): void {
+  // `null` is an object, if we get this, we should just return it.
+  if (obj === null) return
+
+  // An array is an object, but we also want to freeze each element in the array
+  // as well.
+  if (Array.isArray(obj)) {
+    for (const item of obj) {
+      if (!item || typeof item !== 'object') continue
+      freeze(item)
+    }
+
+    Object.freeze(obj)
+    return
+  }
+
+  for (const name of Object.keys(obj)) {
+    const value = obj[name as keyof typeof obj]
+
+    if (!value || typeof value !== 'object') continue
+    freeze(value)
+  }
+
+  Object.freeze(obj)
+  return
+}

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

@@ -1,15 +1,15 @@
 import type { CacheFs } from '../../../shared/lib/utils'
-import type { PrerenderManifest } from '../../../build'
+import type { PrerenderManifest, SsgRoute } from '../../../build'
 import type {
   IncrementalCacheValue,
   IncrementalCacheEntry,
   IncrementalCache as IncrementalCacheType,
   IncrementalCacheKindHint,
 } from '../../response-cache'
+import type { Revalidate } from '../revalidate'
 
 import FetchCache from './fetch-cache'
 import FileSystemCache from './file-system-cache'
-import path from '../../../shared/lib/isomorphic/path'
 import { normalizePagePath } from '../../../shared/lib/page-path/normalize-page-path'
 
 import {
@@ -189,6 +189,31 @@ export class IncrementalCache implements IncrementalCacheType {
     }
   }
 
+  private readonly revalidateSeconds = new Map<string, Revalidate>()
+
+  private getRevalidateSeconds(route: string): Revalidate | undefined {
+    let revalidateSeconds = this.revalidateSeconds.get(route)
+
+    // If we already have an entry for this pathname, return it.
+    if (typeof revalidateSeconds === 'number') {
+      return revalidateSeconds
+    }
+
+    // Otherwise, source it from the prerender manifest.
+    const ssgRoute: SsgRoute | undefined = this.prerenderManifest.routes[route]
+
+    // If there's no entry, return undefined.
+    if (typeof ssgRoute === 'undefined') {
+      return undefined
+    }
+
+    // If there is an entry, store it in the cache and return it.
+    revalidateSeconds = ssgRoute.initialRevalidateSeconds
+    this.revalidateSeconds.set(route, revalidateSeconds)
+
+    return revalidateSeconds
+  }
+
   private calculateRevalidate(
     pathname: string,
     fromTime: number,
@@ -199,12 +224,10 @@ export class IncrementalCache implements IncrementalCacheType {
     if (dev) return new Date().getTime() - 1000
 
     // if an entry isn't present in routes we fallback to a default
-    // of revalidating after 1 second
-    const { initialRevalidateSeconds } = this.prerenderManifest.routes[
-      toRoute(pathname)
-    ] || {
-      initialRevalidateSeconds: 1,
-    }
+    // of revalidating after 1 second.
+    const initialRevalidateSeconds =
+      this.getRevalidateSeconds(toRoute(pathname)) ?? 1
+
     const revalidateAfter =
       typeof initialRevalidateSeconds === 'number'
         ? initialRevalidateSeconds * 1000 + fromTime
@@ -485,8 +508,7 @@ export class IncrementalCache implements IncrementalCacheType {
       }
     }
 
-    const curRevalidate =
-      this.prerenderManifest.routes[toRoute(cacheKey)]?.initialRevalidateSeconds
+    const curRevalidate = this.getRevalidateSeconds(toRoute(cacheKey))
 
     let isStale: boolean | -1 | undefined
     let revalidateAfter: false | number
@@ -584,22 +606,12 @@ export class IncrementalCache implements IncrementalCacheType {
     pathname = this._getPathname(pathname, ctx.fetchCache)
 
     try {
-      // we use the prerender manifest memory instance
-      // to store revalidate timings for calculating
-      // revalidateAfter values so we update this on set
+      // Set the value for the revalidate seconds so if it changes we can
+      // update the cache with the new value.
       if (typeof ctx.revalidate !== 'undefined' && !ctx.fetchCache) {
-        this.prerenderManifest.routes[pathname] = {
-          experimentalPPR: undefined,
-          dataRoute: path.posix.join(
-            '/_next/data',
-            `${normalizePagePath(pathname)}.json`
-          ),
-          srcRoute: null, // FIXME: provide actual source route, however, when dynamically appending it doesn't really matter
-          initialRevalidateSeconds: ctx.revalidate,
-          // Pages routes do not have a prefetch data route.
-          prefetchDataRoute: undefined,
-        }
+        this.revalidateSeconds.set(pathname, ctx.revalidate)
       }
+
       await this.cacheHandler?.set(pathname, data, ctx)
     } catch (error) {
       console.warn('Failed to update prerender cache for', pathname, error)

packages/next/src/server/load-manifest.ts

@@ -1,5 +1,6 @@
 import { readFileSync } from 'fs'
 import { runInNewContext } from 'vm'
+import { freeze } from './lib/freeze'
 
 const cache = new Map<string, unknown>()
 
@@ -8,13 +9,17 @@ export function loadManifest(
   shouldCache: boolean = true
 ): unknown {
   const cached = shouldCache && cache.get(path)
-
   if (cached) {
     return cached
   }
 
   const manifest = JSON.parse(readFileSync(path, 'utf8'))
 
+  // Freeze the manifest so it cannot be modified if we're caching it.
+  if (shouldCache) {
+    freeze(manifest)
+  }
+
   if (shouldCache) {
     cache.set(path, manifest)
   }
@@ -27,7 +32,6 @@ export function evalManifest(
   shouldCache: boolean = true
 ): unknown {
   const cached = shouldCache && cache.get(path)
-
   if (cached) {
     return cached
   }
@@ -40,6 +44,11 @@ export function evalManifest(
   const contextObject = {}
   runInNewContext(content, contextObject)
 
+  // Freeze the context object so it cannot be modified if we're caching it.
+  if (shouldCache) {
+    freeze(contextObject)
+  }
+
   if (shouldCache) {
     cache.set(path, contextObject)
   }

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

@@ -1768,11 +1768,11 @@ export default class NextNodeServer extends BaseServer {
       return this._cachedPreviewManifest
     }
 
-    const manifest = loadManifest(
+    this._cachedPreviewManifest = loadManifest(
       join(this.distDir, PRERENDER_MANIFEST)
     ) as PrerenderManifest
 
-    return (this._cachedPreviewManifest = manifest)
+    return this._cachedPreviewManifest
   }
 
   protected getRoutesManifest(): NormalizedRouteManifest | undefined {