Static generate dynamic sitemaps

packages/next/src/build/index.ts

@@ -483,6 +483,19 @@ export default async function build(
               mappedAppPages[pageKey.replace('[[...__metadata_id__]]/', '')] =
                 pagePath
             }
+
+            if (
+              pageKey.includes('sitemap.xml/[[...__metadata_id__]]') &&
+              isDynamic
+            ) {
+              delete mappedAppPages[pageKey]
+              mappedAppPages[
+                pageKey.replace(
+                  'sitemap.xml/[[...__metadata_id__]]',
+                  'sitemap/[__metadata_id__]'
+                )
+              ] = pagePath
+            }
           }
         }
 

packages/next/src/build/webpack/loaders/next-app-loader.ts

@@ -99,6 +99,7 @@ async function createAppRouteCode({
   const filename = path.parse(resolvedPagePath).name
   if (isMetadataRoute(name) && filename !== 'route') {
     resolvedPagePath = `next-metadata-route-loader?${stringify({
+      page,
       pageExtensions,
     })}!${resolvedPagePath + METADATA_RESOURCE_QUERY}`
   }

packages/next/src/build/webpack/loaders/next-metadata-route-loader.ts

@@ -10,6 +10,7 @@ const cacheHeader = {
 }
 
 type MetadataRouteLoaderOptions = {
+  page: string
   pageExtensions: string[]
 }
 
@@ -127,9 +128,27 @@ export async function GET(_, ctx) {
 `
 }
 
-function getDynamicSiteMapRouteCode(resourcePath: string) {
-  // generateSitemaps
-  return `\
+function getDynamicSiteMapRouteCode(resourcePath: string, page: string) {
+  let staticGenerationCode = ''
+
+  if (
+    process.env.NODE_ENV === 'production' &&
+    page.includes('[__metadata_id__]')
+  ) {
+    staticGenerationCode = `\
+export async function generateStaticParams() {
+  const sitemaps = await generateSitemaps()
+  const params = []
+
+  for (const item of sitemaps) {
+    params.push({ __metadata_id__: item.id.toString() + '.xml' })
+  }
+  return params
+}
+    `
+  }
+
+  const code = `\
 import { NextResponse } from 'next/server'
 import * as _sitemapModule from ${JSON.stringify(resourcePath)}
 import { resolveRouteData } from 'next/dist/build/webpack/loaders/metadata/resolve-route-data'
@@ -172,15 +191,18 @@ export async function GET(_, ctx) {
     },
   })
 }
+
+${staticGenerationCode}
 `
+  return code
 }
 // `import.meta.url` is the resource name of the current module.
 // When it's static route, it could be favicon.ico, sitemap.xml, robots.txt etc.
 // TODO-METADATA: improve the cache control strategy
 const nextMetadataRouterLoader: webpack.LoaderDefinitionFunction<MetadataRouteLoaderOptions> =
   function () {
     const { resourcePath } = this
-    const { pageExtensions } = this.getOptions()
+    const { pageExtensions, page } = this.getOptions()
 
     const { name: fileBaseName, ext } = getFilenameAndExtension(resourcePath)
     const isDynamic = pageExtensions.includes(ext)
@@ -190,7 +212,7 @@ const nextMetadataRouterLoader: webpack.LoaderDefinitionFunction<MetadataRouteLo
       if (fileBaseName === 'robots' || fileBaseName === 'manifest') {
         code = getDynamicTextRouteCode(resourcePath)
       } else if (fileBaseName === 'sitemap') {
-        code = getDynamicSiteMapRouteCode(resourcePath)
+        code = getDynamicSiteMapRouteCode(resourcePath, page)
       } else {
         code = getDynamicImageRouteCode(resourcePath)
       }

test/e2e/app-dir/metadata-dynamic-routes/app/gsp/page.tsx

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>gsp</div>
+}

test/e2e/app-dir/metadata-dynamic-routes/index.test.ts

@@ -159,10 +159,12 @@ createNextDescribe(
       })
 
       it('should support generate multi sitemaps with generateSitemaps', async () => {
-        const ids = [0, 1, 2, 3]
+        const ids = [0, 1, 2]
         function fetchSitemap(id) {
           return next
-            .fetch(`/dynamic/small/sitemap.xml/${id}`)
+            .fetch(
+              isNextDev ? `/gsp/sitemap.xml/${id}` : `/gsp/sitemap/${id}.xml`
+            )
             .then((res) => res.text())
         }
 
@@ -434,13 +436,23 @@ createNextDescribe(
           '/sitemap.xml/route': 'app/sitemap.xml/route.js',
 
           // dynamic
-          '/(group)/dynamic/[size]/sitemap.xml/[[...__metadata_id__]]/route':
-            'app/(group)/dynamic/[size]/sitemap.xml/[[...__metadata_id__]]/route.js',
+          '/gsp/sitemap/[__metadata_id__]/route':
+            'app/gsp/sitemap/[__metadata_id__]/route.js',
           '/(group)/dynamic/[size]/apple-icon-48jo90/[[...__metadata_id__]]/route':
             'app/(group)/dynamic/[size]/apple-icon-48jo90/[[...__metadata_id__]]/route.js',
         })
       })
 
+      it('should generate static paths of dynamic sitemap in production', async () => {
+        const sitemapPaths = [0, 1, 2].map(
+          (id) => `.next/server/app/gsp/sitemap/${id}.xml.meta`
+        )
+        const promises = sitemapPaths.map(async (filePath) => {
+          expect(await next.hasFile(filePath)).toBe(true)
+        })
+        await Promise.all(promises)
+      })
+
       it('should include default og font files in file trace', async () => {
         const fileTrace = JSON.parse(
           await next.readFile(