From a647e98458dde6a96d976f1663241bb6003574ac Mon Sep 17 00:00:00 2001
From: Hendrik Liebau <mail@hendrik-liebau.de>
Date: Fri, 21 Feb 2025 10:23:08 +0100
Subject: [PATCH] Add `fallbackExpire` to prerender manifest

---
 packages/next/src/build/index.ts             | 20 ++++++++----
 test/e2e/app-dir/use-cache/app/[id]/page.tsx |  7 ++++-
 test/e2e/app-dir/use-cache/use-cache.test.ts | 32 ++++++++++----------
 3 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/packages/next/src/build/index.ts b/packages/next/src/build/index.ts
index 44187bd82855bd..70c39c50987519 100644
--- a/packages/next/src/build/index.ts
+++ b/packages/next/src/build/index.ts
@@ -279,6 +279,11 @@ export interface DynamicPrerenderManifestRoute {
    */
   fallbackRevalidate: Revalidate | undefined
 
+  /**
+   * When defined, it describes the expire configuration for the fallback route.
+   */
+  fallbackExpire: Revalidate | undefined
+
   /**
    * The headers that should used when serving the fallback.
    */
@@ -3037,12 +3042,13 @@ export default async function build(
                 const fallbackMode =
                   route.fallbackMode ?? FallbackMode.NOT_FOUND
 
-                // When we're configured to serve a prerender, we should use the
-                // fallback revalidate from the export result. If it can't be
-                // found, mark that we should keep the shell forever (`false`).
-                let fallbackRevalidate: Revalidate | undefined =
+                // When the route is configured to serve a prerender, we should
+                // use the cache control from the export result. If it can't be
+                // found, mark that we should keep the shell forever
+                // (revalidate: `false` via `getCacheControl()`).
+                const fallbackCacheControl =
                   isRoutePPREnabled && fallbackMode === FallbackMode.PRERENDER
-                    ? cacheControl.revalidate
+                    ? cacheControl
                     : undefined
 
                 const fallback: Fallback = fallbackModeToFallbackField(
@@ -3072,7 +3078,8 @@ export default async function build(
                   ),
                   dataRoute,
                   fallback,
-                  fallbackRevalidate,
+                  fallbackRevalidate: fallbackCacheControl?.revalidate,
+                  fallbackExpire: fallbackCacheControl?.expire,
                   fallbackStatus: meta.status,
                   fallbackHeaders: meta.headers,
                   fallbackRootParams: route.fallbackRootParams,
@@ -3521,6 +3528,7 @@ export default async function build(
                 ? `${normalizedRoute}.html`
                 : false,
             fallbackRevalidate: undefined,
+            fallbackExpire: undefined,
             fallbackSourceRoute: undefined,
             fallbackRootParams: undefined,
             dataRouteRegex: normalizeRouteRegex(
diff --git a/test/e2e/app-dir/use-cache/app/[id]/page.tsx b/test/e2e/app-dir/use-cache/app/[id]/page.tsx
index 74f4ed6d08dc30..7ba0b38ddee352 100644
--- a/test/e2e/app-dir/use-cache/app/[id]/page.tsx
+++ b/test/e2e/app-dir/use-cache/app/[id]/page.tsx
@@ -1,5 +1,8 @@
+import { unstable_cacheLife } from 'next/cache'
+
 async function getCachedRandom(n: number) {
   'use cache'
+  unstable_cacheLife('weeks')
   return String(Math.ceil(Math.random() * n))
 }
 
@@ -11,5 +14,7 @@ export async function generateStaticParams() {
 }
 
 export default async function Page() {
-  return 'hit'
+  const value = getCachedRandom(1)
+
+  return <p>{value}</p>
 }
diff --git a/test/e2e/app-dir/use-cache/use-cache.test.ts b/test/e2e/app-dir/use-cache/use-cache.test.ts
index 38c7e698454224..95299bfae9239e 100644
--- a/test/e2e/app-dir/use-cache/use-cache.test.ts
+++ b/test/e2e/app-dir/use-cache/use-cache.test.ts
@@ -7,6 +7,7 @@ import {
   createRenderResumeDataCache,
   RenderResumeDataCache,
 } from 'next/dist/server/resume-data-cache/resume-data-cache'
+import { PrerenderManifest } from 'next/dist/build'
 
 const GENERIC_RSC_ERROR =
   'An error occurred in the Server Components render. The specific message is omitted in production builds to avoid leaking sensitive details. A digest property is included on this error instance which may provide additional details about the nature of the error.'
@@ -371,29 +372,28 @@ describe('use-cache', () => {
     })
 
     it('should match the expected revalidate and expire configs on the prerender manifest', async () => {
-      const prerenderManifest = JSON.parse(
+      const { version, routes, dynamicRoutes } = JSON.parse(
         await next.readFile('.next/prerender-manifest.json')
-      )
+      ) as PrerenderManifest
 
-      expect(prerenderManifest.version).toBe(4)
+      expect(version).toBe(4)
 
-      expect(
-        prerenderManifest.routes['/cache-life'].initialRevalidateSeconds
-      ).toBe(100)
-
-      expect(prerenderManifest.routes['/cache-life'].initialExpireSeconds).toBe(
-        250
-      )
+      // custom cache life profile "frequent"
+      expect(routes['/cache-life'].initialRevalidateSeconds).toBe(100)
+      expect(routes['/cache-life'].initialExpireSeconds).toBe(250)
 
-      expect(
-        prerenderManifest.routes['/cache-fetch'].initialExpireSeconds
-      ).toBe(31536000) // default expireTime
+      // default expireTime
+      expect(routes['/cache-fetch'].initialExpireSeconds).toBe(31536000)
 
       // The revalidate config from the fetch call should lower the revalidate
       // config for the page.
-      expect(
-        prerenderManifest.routes['/cache-tag'].initialRevalidateSeconds
-      ).toBe(42)
+      expect(routes['/cache-tag'].initialRevalidateSeconds).toBe(42)
+
+      if (process.env.__NEXT_EXPERIMENTAL_PPR === 'true') {
+        // cache life profile "weeks"
+        expect(dynamicRoutes['/[id]'].fallbackRevalidate).toBe(604800)
+        expect(dynamicRoutes['/[id]'].fallbackExpire).toBe(2592000)
+      }
     })
 
     it('should match the expected stale config in the page header', async () => {