fix: handle extensionless manifests and add prefetch-hints

nathanschram · claude · nathanschram · commit a695016fa7c9 · 2026-03-21T08:40:05.000Z
- Fix prettier formatting in changeset
- Strip .json extension before matching optional manifests since Next.js
  defines some constants without it (SUBRESOURCE_INTEGRITY_MANIFEST,
  DYNAMIC_CSS_MANIFEST, SERVER_REFERENCE_MANIFEST)
- Add prefetch-hints to the optional manifest list (new in Next.js 16.2)
- All 236 tests pass, tsc clean, prettier clean

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/.changeset/fix-load-manifest-graceful-fallback.md b/.changeset/fix-load-manifest-graceful-fallback.md
@@ -10,12 +10,17 @@ generated, so the patched function threw at runtime, crashing dynamic routes wit
 
 Instead of a blanket catch-all, handle only the specific optional manifests from Next.js
 `route-module.ts`:
-- `react-loadable-manifest.json` (Turbopack per-route, not all routes have dynamic imports)
-- `subresource-integrity-manifest.json` (only when `experimental.sri` configured)
-- `server-reference-manifest.json` (App Router only)
-- `dynamic-css-manifest.json` (Pages Router + Webpack only)
-- `fallback-build-manifest.json` (only for `/_error` page)
-- `_client-reference-manifest.js` (optional for static metadata routes)
+
+- `react-loadable-manifest` (Turbopack per-route, not all routes have dynamic imports)
+- `subresource-integrity-manifest` (only when `experimental.sri` configured)
+- `server-reference-manifest` (App Router only)
+- `dynamic-css-manifest` (Pages Router + Webpack only)
+- `fallback-build-manifest` (only for `/_error` page)
+- `prefetch-hints` (new in Next.js 16.2)
+- `_client-reference-manifest.js` (optional for static metadata routes, evalManifest)
+
+Manifest matching strips `.json` before comparison since some Next.js constants omit
+the extension (`SUBRESOURCE_INTEGRITY_MANIFEST`, `DYNAMIC_CSS_MANIFEST`, etc.).
 
 Unknown manifests still throw to surface genuine errors.
 
diff --git a/packages/cloudflare/src/cli/build/patches/plugins/load-manifest.ts b/packages/cloudflare/src/cli/build/patches/plugins/load-manifest.ts
@@ -69,12 +69,19 @@ function loadManifest($PATH, $$$ARGS) {
   // Known optional manifests \u2014 Next.js loads these with handleMissing: true
   // (see vercel/next.js packages/next/src/server/route-modules/route-module.ts).
   // Return {} to match Next.js behaviour instead of crashing the worker.
-  if ($PATH.endsWith("react-loadable-manifest.json") ||
-      $PATH.endsWith("subresource-integrity-manifest.json") ||
-      $PATH.endsWith("server-reference-manifest.json") ||
-      $PATH.endsWith("dynamic-css-manifest.json") ||
-      $PATH.endsWith("fallback-build-manifest.json")) {
-    return {};
+  // Note: Some manifest constants in Next.js omit the .json extension
+  // (e.g. SUBRESOURCE_INTEGRITY_MANIFEST, DYNAMIC_CSS_MANIFEST), so we
+  // strip .json before matching to handle both forms.
+  {
+    const p = $PATH.replace(/\\.json$/, "");
+    if (p.endsWith("react-loadable-manifest") ||
+        p.endsWith("subresource-integrity-manifest") ||
+        p.endsWith("server-reference-manifest") ||
+        p.endsWith("dynamic-css-manifest") ||
+        p.endsWith("fallback-build-manifest") ||
+        p.endsWith("prefetch-hints")) {
+      return {};
+    }
   }
   throw new Error(\`Unexpected loadManifest(\${$PATH}) call!\`);
 }`,
