feat(prerender): support layout-level generateStaticParams

packages/vinext/src/build/prerender.ts

@@ -264,7 +264,6 @@ export type StaticParamsMap = Record<
  */
 export async function resolveParentParams(
   childRoute: AppRoute,
-  routeIndex: ReadonlyMap<string, AppRoute>,
   staticParamsMap: StaticParamsMap,
 ): Promise<Record<string, string | string[]>[]> {
   const { patternParts } = childRoute;
@@ -292,18 +291,12 @@ export async function resolveParentParams(
     prefixPattern += "/" + part;
     if (!part.startsWith(":")) continue;
 
-    const parentRoute = routeIndex.get(prefixPattern);
-    // TODO: layout-level generateStaticParams — a layout segment can define
-    // generateStaticParams without a corresponding page file, so parentRoute
-    // may be undefined here even though the layout exports generateStaticParams.
-    // resolveParentParams currently only looks up routes that have a pagePath
-    // (i.e. leaf pages), missing layout-level providers. Fix requires scanning
-    // layout files in addition to page files during route collection.
-    if (parentRoute?.pagePath) {
-      const fn = staticParamsMap[prefixPattern];
-      if (typeof fn === "function") {
-        parentSegments.push(fn);
-      }
+    // Check staticParamsMap directly — it now includes both page-level and
+    // layout-level generateStaticParams entries, so we don't need to verify
+    // that a page route exists at this prefix pattern.
+    const fn = staticParamsMap[prefixPattern];
+    if (typeof fn === "function") {
+      parentSegments.push(fn);
     }
   }
 
@@ -314,7 +307,12 @@ export async function resolveParentParams(
     const nextParams: Record<string, string | string[]>[] = [];
     for (const parentParams of currentParams) {
       const results = await generateStaticParams({ params: parentParams });
-      if (Array.isArray(results)) {
+      if (results === null) {
+        // No generateStaticParams at this level (e.g. CF Workers Proxy returned
+        // null for a prefix with no layout/page). Pass parent params through
+        // unchanged so deeper parent segments can still be resolved.
+        nextParams.push(parentParams);
+      } else if (Array.isArray(results)) {
         for (const result of results) {
           nextParams.push({ ...parentParams, ...result });
         }
@@ -802,8 +800,6 @@ export async function prerenderApp({
       },
     });
 
-    const routeIndex = new Map(routes.map((r) => [r.pattern, r]));
-
     // ── Collect URLs to render ────────────────────────────────────────────────
     type UrlToRender = {
       urlPath: string;
@@ -887,7 +883,7 @@ export async function prerenderApp({
             continue;
           }
 
-          const parentParamSets = await resolveParentParams(route, routeIndex, staticParamsMap);
+          const parentParamSets = await resolveParentParams(route, staticParamsMap);
           let paramSets: Record<string, string | string[]>[] | null;
 
           if (parentParamSets.length > 0) {

packages/vinext/src/entries/app-rsc-entry.ts

@@ -16,6 +16,7 @@ import type {
   NextRewrite,
 } from "../config/next-config.js";
 import type { AppRoute } from "../routing/app-router.js";
+import { decodeRouteSegment } from "../routing/utils.js";
 import { generateDevOriginCheckCode } from "../server/dev-origin-check.js";
 import type { MetadataFileRoute } from "../server/metadata-routes.js";
 import {
@@ -1320,18 +1321,70 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
-${routes
-  .filter((r) => r.isDynamic && r.pagePath)
-  .map(
-    (r) =>
-      `  ${JSON.stringify(r.pattern)}: ${getImportVar(r.pagePath!)}?.generateStaticParams ?? null,`,
-  )
-  .join("\n")}
+${(() => {
+  const entries: string[] = [];
+  const emittedPatterns = new Set<string>();
+
+  // 1. Page-level entries (leaf pages with generateStaticParams)
+  for (const r of routes) {
+    if (r.isDynamic && r.pagePath) {
+      entries.push(
+        `  ${JSON.stringify(r.pattern)}: ${getImportVar(r.pagePath)}?.generateStaticParams ?? null,`,
+      );
+      emittedPatterns.add(r.pattern);
+    }
+  }
+
+  // 2. Layout-level entries (layouts at dynamic segments that may export generateStaticParams)
+  for (const r of routes) {
+    if (!r.isDynamic) continue;
+    for (let li = 0; li < r.layouts.length; li++) {
+      const layoutDepth = r.layoutTreePositions[li];
+      // Build the prefix pattern from routeSegments up to this layout's depth
+      const prefixSegments = r.routeSegments.slice(0, layoutDepth);
+      // Convert filesystem segments to URL pattern parts (same logic as convertSegmentsToRouteParts)
+      const urlParts: string[] = [];
+      let hasDynamic = false;
+      for (const seg of prefixSegments) {
+        // Skip invisible segments
+        if (seg === "." || (seg.startsWith("(") && seg.endsWith(")")) || seg.startsWith("@"))
+          continue;
+        // Catch-all
+        const catchAll = seg.match(/^\[\.\.\.([\w-]+)\]$/);
+        if (catchAll) {
+          urlParts.push(`:${catchAll[1]}+`);
+          hasDynamic = true;
+          continue;
+        }
+        // Optional catch-all
+        const optCatchAll = seg.match(/^\[\[\.\.\.([\w-]+)\]\]$/);
+        if (optCatchAll) {
+          urlParts.push(`:${optCatchAll[1]}*`);
+          hasDynamic = true;
+          continue;
+        }
+        // Dynamic segment
+        const dyn = seg.match(/^\[([\w-]+)\]$/);
+        if (dyn) {
+          urlParts.push(`:${dyn[1]}`);
+          hasDynamic = true;
+          continue;
+        }
+        // Static segment — decode percent-encoded chars to match convertSegmentsToRouteParts
+        urlParts.push(decodeRouteSegment(seg));
+      }
+      if (!hasDynamic) continue;
+      const prefixPattern = "/" + urlParts.join("/");
+      if (emittedPatterns.has(prefixPattern)) continue;
+      emittedPatterns.add(prefixPattern);
+      entries.push(
+        `  ${JSON.stringify(prefixPattern)}: ${getImportVar(r.layouts[li])}?.generateStaticParams ?? null,`,
+      );
+    }
+  }
+
+  return entries.join("\n");
+})()}
 };
 
 export default async function handler(request, ctx) {

tests/__snapshots__/entry-templates.test.ts.snap

@@ -1246,11 +1246,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };
 
@@ -3440,11 +3435,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };
 
@@ -5646,11 +5636,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };
 
@@ -7870,11 +7855,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };
 
@@ -10074,11 +10054,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };
 
@@ -12497,11 +12472,6 @@ async function __readFormDataWithLimit(request, maxBytes) {
 // Used by the prerender phase to enumerate dynamic route URLs without
 // loading route modules via the dev server.
 export const generateStaticParamsMap = {
-// TODO: layout-level generateStaticParams — this map only includes routes that
-// have a pagePath (leaf pages). Layout segments can also export generateStaticParams
-// to provide parent params for nested dynamic routes, but they don't have a pagePath
-// so they are excluded here. Supporting layout-level generateStaticParams requires
-// scanning layout.tsx files separately and including them in this map.
   "/blog/:slug": mod_3?.generateStaticParams ?? null,
 };