Ensure config and fetch revalidate are honored (#47255)

This ensures revalidate can be fetch specific instead of cache key
specific and adds a test case to ensure config based revalidate isn't
overridden by fetch based revalidate.

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

@@ -11,7 +11,34 @@ export default class FetchCache implements CacheHandler {
   private debug: boolean
 
   constructor(ctx: CacheHandlerContext) {
+    this.debug = !!process.env.NEXT_PRIVATE_DEBUG_CACHE
+    this.headers = {}
+    this.headers['Content-Type'] = 'application/json'
+
+    if (FETCH_CACHE_HEADER in ctx._requestHeaders) {
+      const newHeaders = JSON.parse(
+        ctx._requestHeaders[FETCH_CACHE_HEADER] as string
+      )
+      for (const k in newHeaders) {
+        this.headers[k] = newHeaders[k]
+      }
+      delete ctx._requestHeaders[FETCH_CACHE_HEADER]
+    }
+    if (ctx._requestHeaders['x-vercel-sc-host']) {
+      this.cacheEndpoint = `https://${ctx._requestHeaders['x-vercel-sc-host']}${
+        ctx._requestHeaders['x-vercel-sc-basepath'] || ''
+      }`
+      if (this.debug) {
+        console.log('using cache endpoint', this.cacheEndpoint)
+      }
+    } else if (this.debug) {
+      console.log('no cache endpoint available')
+    }
+
     if (ctx.maxMemoryCacheSize && !memoryCache) {
+      if (this.debug) {
+        console.log('using memory store for fetch cache')
+      }
       memoryCache = new LRUCache({
         max: ctx.maxMemoryCacheSize,
         length({ value }) {
@@ -32,29 +59,10 @@ export default class FetchCache implements CacheHandler {
           )
         },
       })
-    }
-    this.debug = !!process.env.NEXT_PRIVATE_DEBUG_CACHE
-    this.headers = {}
-    this.headers['Content-Type'] = 'application/json'
-
-    if (FETCH_CACHE_HEADER in ctx._requestHeaders) {
-      const newHeaders = JSON.parse(
-        ctx._requestHeaders[FETCH_CACHE_HEADER] as string
-      )
-      for (const k in newHeaders) {
-        this.headers[k] = newHeaders[k]
-      }
-      delete ctx._requestHeaders[FETCH_CACHE_HEADER]
-    }
-    if (ctx._requestHeaders['x-vercel-sc-host']) {
-      this.cacheEndpoint = `https://${ctx._requestHeaders['x-vercel-sc-host']}${
-        ctx._requestHeaders['x-vercel-sc-basepath'] || ''
-      }`
+    } else {
       if (this.debug) {
-        console.log('using cache endpoint', this.cacheEndpoint)
+        console.log('not using memory store for fetch cache')
       }
-    } else if (this.debug) {
-      console.log('no cache endpoint available')
     }
   }
 

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

@@ -265,7 +265,8 @@ export class IncrementalCache {
   // get data from cache if available
   async get(
     pathname: string,
-    fetchCache?: boolean
+    fetchCache?: boolean,
+    revalidate?: number
   ): Promise<IncrementalCacheEntry | null> {
     // we don't leverage the prerender cache in dev mode
     // so that getStaticProps is always called for easier debugging
@@ -281,7 +282,7 @@ export class IncrementalCache {
     const cacheData = await this.cacheHandler?.get(pathname, fetchCache)
 
     if (cacheData?.value?.kind === 'FETCH') {
-      const revalidate = cacheData.value.revalidate
+      revalidate = revalidate || cacheData.value.revalidate
       const age = Math.round(
         (Date.now() - (cacheData.lastModified || 0)) / 1000
       )

packages/next/src/server/lib/patch-fetch.ts

@@ -218,7 +218,8 @@ export function patchFetch({
       if (cacheKey && staticGenerationStore?.incrementalCache) {
         const entry = await staticGenerationStore.incrementalCache.get(
           cacheKey,
-          true
+          true,
+          revalidate
         )
 
         if (entry?.value && entry.value.kind === 'FETCH') {

test/e2e/app-dir/app-static/app-static.test.ts

@@ -50,6 +50,41 @@ createNextDescribe(
       })
     }
 
+    it('should revalidate correctly with config and fetch revalidate', async () => {
+      const initial$ = await next.render$(
+        '/variable-config-revalidate/revalidate-3'
+      )
+      const initialDate = initial$('#date').text()
+      const initialData = initial$('#data').text()
+
+      expect(initialDate).toBeTruthy()
+      expect(initialData).toBeTruthy()
+
+      let revalidatedDate
+      let revalidatedData
+
+      // wait for a fresh revalidation
+      await check(async () => {
+        const $ = await next.render$('/variable-config-revalidate/revalidate-3')
+
+        revalidatedDate = $('#date').text()
+        revalidatedData = $('#data').text()
+
+        expect(revalidatedData).not.toBe(initialDate)
+        expect(revalidatedDate).not.toBe(initialData)
+        return 'success'
+      }, 'success')
+
+      // the date should revalidate first after 3 seconds
+      // while the fetch data stays in place for 15 seconds
+      await check(async () => {
+        const $ = await next.render$('/variable-config-revalidate/revalidate-3')
+        expect($('#date').text()).not.toBe(revalidatedDate)
+        expect($('#data').text()).toBe(revalidatedData)
+        return 'success'
+      }, 'success')
+    })
+
     it('should include statusCode in cache', async () => {
       const $ = await next.render$('/variable-revalidate/status-code')
       const origData = JSON.parse($('#page-data').text())
@@ -163,6 +198,9 @@ createNextDescribe(
           'ssr-forced/page.js',
           'static-to-dynamic-error-forced/[id]/page.js',
           'static-to-dynamic-error/[id]/page.js',
+          'variable-config-revalidate/revalidate-3.html',
+          'variable-config-revalidate/revalidate-3.rsc',
+          'variable-config-revalidate/revalidate-3/page.js',
           'variable-revalidate-edge/encoding/page.js',
           'variable-revalidate-edge/no-store/page.js',
           'variable-revalidate-edge/post-method-request/page.js',
@@ -367,6 +405,11 @@ createNextDescribe(
             initialRevalidateSeconds: false,
             srcRoute: '/ssg-preview/[[...route]]',
           },
+          '/variable-config-revalidate/revalidate-3': {
+            dataRoute: '/variable-config-revalidate/revalidate-3.rsc',
+            initialRevalidateSeconds: 3,
+            srcRoute: '/variable-config-revalidate/revalidate-3',
+          },
           '/variable-revalidate/authorization': {
             dataRoute: '/variable-revalidate/authorization.rsc',
             initialRevalidateSeconds: 10,

test/e2e/app-dir/app-static/app/variable-config-revalidate/revalidate-3/page.js

@@ -0,0 +1,24 @@
+export const revalidate = 3
+
+export const metadata = {
+  title: 'Cache Test',
+}
+
+export default async function Page() {
+  const data = await fetch(
+    'https://next-data-api-endpoint.vercel.app/api/random',
+    {
+      next: {
+        revalidate: 15,
+      },
+    }
+  ).then((res) => res.text())
+
+  return (
+    <>
+      <p>/variable-config-revalidate/revalidate-3</p>
+      <p id="date">{Date.now()}</p>
+      <p id="data">{data}</p>
+    </>
+  )
+}