bugfix: static resources staleTime should be renewed once refetched

Author: ztanner

packages/next/src/client/components/router-reducer/prefetch-cache-utils.ts

@@ -404,22 +404,7 @@ function getPrefetchEntryCacheStatus({
   kind,
   prefetchTime,
   lastUsedTime,
-  staleTime,
 }: PrefetchCacheEntry): PrefetchCacheEntryStatus {
-  if (staleTime !== -1) {
-    // `staleTime` is the value sent by the server during static generation.
-    // When this is available, it takes precedence over any of the heuristics
-    // that follow.
-    //
-    // TODO: When PPR is enabled, the server will *always* return a stale time
-    // when prefetching. We should never use a prefetch entry that hasn't yet
-    // received data from the server. So the only two cases should be 1) we use
-    // the server-generated stale time 2) the unresolved entry is discarded.
-    return Date.now() < prefetchTime + staleTime
-      ? PrefetchCacheEntryStatus.fresh
-      : PrefetchCacheEntryStatus.stale
-  }
-
   // We will re-use the cache entry data for up to the `dynamic` staletime window.
   if (Date.now() < (lastUsedTime ?? prefetchTime) + DYNAMIC_STALETIME_MS) {
     return lastUsedTime

test/e2e/app-dir/app-prefetch/prefetching.stale-times.test.ts

@@ -137,9 +137,11 @@ describe('app dir - prefetching (custom staleTime)', () => {
     let requests: string[] = []
 
     browser.on('request', (req) => {
-      // only consider requests that have RSC header but not the prefetch header
-      if (req.headers()['rsc'] && !req.headers()['next-router-prefetch']) {
-        requests.push(new URL(req.url()).pathname)
+      const path = new URL(req.url()).pathname
+      const headers = req.headers()
+
+      if (headers['rsc']) {
+        requests.push(path)
       }
     })
 
@@ -164,4 +166,73 @@ describe('app dir - prefetching (custom staleTime)', () => {
       ).toHaveLength(1)
     })
   })
+
+  it('should renew the stale time after refetching expired RSC data', async () => {
+    const browser = await next.browser('/404')
+    let requests: string[] = []
+
+    browser.on('request', (req) => {
+      requests.push(new URL(req.url()).pathname)
+    })
+
+    // Navigate to home and wait for static page to be prefetched
+    await browser.eval('location.href = "/"')
+
+    await retry(async () => {
+      expect(
+        requests.filter((request) => request === '/static-page')
+      ).toHaveLength(1)
+    })
+
+    // Navigate to static page (should use cached data)
+    await browser
+      .elementByCss('#to-static-page')
+      .click()
+      .waitForElementByCss('#static-page')
+
+    // Go back to home
+    await browser
+      .elementByCss('#to-home')
+      .click()
+      .waitForElementByCss('#to-static-page')
+
+    // Wait for stale time to expire (10 seconds)
+    await waitFor(10000)
+
+    // Navigate to static page again (should refetch due to expired cache)
+    await browser
+      .elementByCss('#to-static-page')
+      .click()
+      .waitForElementByCss('#static-page')
+
+    // Verify that refetch happened
+    await retry(async () => {
+      expect(
+        requests.filter((request) => request === '/static-page')
+      ).toHaveLength(2)
+    })
+
+    // Go back to home
+    await browser
+      .elementByCss('#to-home')
+      .click()
+      .waitForElementByCss('#to-static-page')
+
+    // Wait less than the stale time (5 seconds - should still be fresh)
+    await waitFor(5000)
+
+    // Navigate to static page again (should NOT refetch - stale time should be renewed)
+    await browser
+      .elementByCss('#to-static-page')
+      .click()
+      .waitForElementByCss('#static-page')
+
+    // This should still be 2 - no new request should have been made
+    // If this fails, it means the stale time was not renewed after the refetch
+    await retry(async () => {
+      expect(
+        requests.filter((request) => request === '/static-page')
+      ).toHaveLength(2)
+    })
+  })
 })