fix(next): properly pass layout-level maxDuration config to the chi…

…ldren page segments on build (vercel#68793)

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> This PR is recommended to [hide
whitespace](https://github.blog/news-insights/product-news/ignore-white-space-in-code-review/)
when reviewing.

### What?

Fixed layouts to properly pass route segment config `maxDuration` to
their children page segments.

```tsx
// layout.tsx

export const maxDuration = 5

```

### Why?

- We separately handle the route segment configs on different places.
- `maxDuration` was missing logic to get value from the layouts unlike
[other route segment
configs](https://github.com/vercel/next.js/blob/canary/packages/next/src/build/utils.ts#L1636-L1652).

### How?

- Instead of explicit logic for the `maxDuration`, get the route segment
configs from the layout on the page's static info.
- Ensure to inherit the value from the layout only if is a page segment.

#### See Changes by Commits

- current: 522b953
- expected: 12496d4
- fix: 196e0e8

Fixes NDX-196

packages/next/src/build/entries.ts

@@ -64,16 +64,14 @@ import {
   isInternalComponent,
   isNonRoutePagesPage,
 } from '../lib/is-internal-component'
-import {
-  isMetadataRoute,
-  isStaticMetadataRouteFile,
-} from '../lib/metadata/is-metadata-route'
+import { isMetadataRoute } from '../lib/metadata/is-metadata-route'
 import { RouteKind } from '../server/route-kind'
 import { encodeToBase64 } from './webpack/loaders/utils'
 import { normalizeCatchAllRoutes } from './normalize-catchall-routes'
 import type { PageExtensions } from './page-extensions-type'
 import type { MappedPages } from './build-context'
 import { PAGE_TYPES } from '../lib/page-types'
+import { isAppPageRoute } from '../lib/is-app-page-route'
 
 export function sortByPageExts(pageExtensions: PageExtensions) {
   return (a: string, b: string) => {
@@ -119,17 +117,21 @@ export async function getStaticInfoIncludingLayouts({
     pageFilePath,
     isDev,
     page,
+    // TODO: sync types for pages: PAGE_TYPES, ROUTER_TYPE, 'app' | 'pages', etc.
     pageType: isInsideAppDir ? PAGE_TYPES.APP : PAGE_TYPES.PAGES,
   })
 
-  const staticInfo: PageStaticInfo = isInsideAppDir
-    ? {
-        // TODO-APP: Remove the rsc key altogether. It's no longer required.
-        rsc: 'server',
-      }
-    : pageStaticInfo
+  if (!isInsideAppDir || !appDir) {
+    return pageStaticInfo
+  }
 
-  if (isInsideAppDir && appDir) {
+  const staticInfo: PageStaticInfo = {
+    // TODO-APP: Remove the rsc key altogether. It's no longer required.
+    rsc: 'server',
+  }
+
+  // inherit from layout files only if it's a page route
+  if (isAppPageRoute(page)) {
     const layoutFiles = []
     const potentialLayoutFiles = pageExtensions.map((ext) => 'layout.' + ext)
     let dir = dirname(pageFilePath)
@@ -162,22 +164,28 @@ export async function getStaticInfoIncludingLayouts({
       if (layoutStaticInfo.preferredRegion) {
         staticInfo.preferredRegion = layoutStaticInfo.preferredRegion
       }
+      if (layoutStaticInfo.extraConfig) {
+        staticInfo.extraConfig = {
+          ...staticInfo.extraConfig,
+          ...layoutStaticInfo.extraConfig,
+        }
+      }
     }
+  }
 
-    if (pageStaticInfo.runtime) {
-      staticInfo.runtime = pageStaticInfo.runtime
-    }
-    if (pageStaticInfo.preferredRegion) {
-      staticInfo.preferredRegion = pageStaticInfo.preferredRegion
-    }
-
-    // if it's static metadata route, don't inherit runtime from layout
-    const relativePath = pageFilePath.replace(appDir, '')
-    if (isStaticMetadataRouteFile(relativePath)) {
-      delete staticInfo.runtime
-      delete staticInfo.preferredRegion
+  if (pageStaticInfo.runtime) {
+    staticInfo.runtime = pageStaticInfo.runtime
+  }
+  if (pageStaticInfo.preferredRegion) {
+    staticInfo.preferredRegion = pageStaticInfo.preferredRegion
+  }
+  if (pageStaticInfo.extraConfig) {
+    staticInfo.extraConfig = {
+      ...staticInfo.extraConfig,
+      ...pageStaticInfo.extraConfig,
     }
   }
+
   return staticInfo
 }
 

packages/next/src/build/index.ts

@@ -100,11 +100,13 @@ import {
 } from '../telemetry/events'
 import type { EventBuildFeatureUsage } from '../telemetry/events'
 import { Telemetry } from '../telemetry/storage'
+import { hadUnsupportedValue } from './analysis/get-page-static-info'
 import {
-  getPageStaticInfo,
-  hadUnsupportedValue,
-} from './analysis/get-page-static-info'
-import { createPagesMapping, getPageFromPath, sortByPageExts } from './entries'
+  createPagesMapping,
+  getPageFromPath,
+  getStaticInfoIncludingLayouts,
+  sortByPageExts,
+} from './entries'
 import { PAGE_TYPES } from '../lib/page-types'
 import { generateBuildId } from './generate-build-id'
 import { isWriteable } from './is-writeable'
@@ -2018,13 +2020,19 @@ export default async function build(
                       pagePath
                     )
 
+                const isInsideAppDir = pageType === 'app'
                 const staticInfo = pagePath
-                  ? await getPageStaticInfo({
+                  ? await getStaticInfoIncludingLayouts({
+                      isInsideAppDir,
                       pageFilePath,
-                      nextConfig: config,
-                      // TODO: fix type mismatch
-                      pageType:
-                        pageType === 'app' ? PAGE_TYPES.APP : PAGE_TYPES.PAGES,
+                      pageExtensions: config.pageExtensions,
+                      appDir,
+                      config,
+                      isDev: false,
+                      // If this route is an App Router page route, inherit the
+                      // route segment configs (e.g. `runtime`) from the layout by
+                      // passing the `originalAppPath`, which should end with `/page`.
+                      page: isInsideAppDir ? originalAppPath! : page,
                     })
                   : undefined
 

test/e2e/app-dir/with-exported-function-config/app/app-layout/inner/page.tsx

@@ -0,0 +1,6 @@
+export default function Page() {
+  return <p>app-layout</p>
+}
+
+// overwrite ../layout's maxDuration
+export const maxDuration = 2

test/e2e/app-dir/with-exported-function-config/app/app-layout/layout.tsx

@@ -0,0 +1,5 @@
+export default function Layout({ children }: { children: React.ReactNode }) {
+  return <>{children}</>
+}
+
+export const maxDuration = 1

test/e2e/app-dir/with-exported-function-config/app/app-layout/page.tsx

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p>app-layout</p>
+}

test/e2e/app-dir/with-exported-function-config/with-exported-function-config.test.ts

@@ -11,34 +11,38 @@ describe('with-exported-function-config', () => {
         await next.readFile('.next/server/functions-config-manifest.json')
       )
 
-      expect(functionsConfigManifest).toMatchInlineSnapshot(`
-        {
-          "functions": {
-            "/api/page-route": {
-              "maxDuration": 1,
-            },
-            "/app-route": {
-              "maxDuration": 1,
-            },
-            "/app-route-edge": {
-              "maxDuration": 2,
-            },
-            "/app-ssr": {
-              "maxDuration": 3,
-            },
-            "/app-ssr-edge": {
-              "maxDuration": 4,
-            },
-            "/page": {
-              "maxDuration": 2,
-            },
-            "/page-ssr": {
-              "maxDuration": 3,
-            },
-          },
-          "version": 1,
-        }
-      `)
+      expect(functionsConfigManifest).toEqual({
+        functions: {
+          '/api/page-route': {
+            maxDuration: 1,
+          },
+          '/app-layout': {
+            maxDuration: 1,
+          },
+          '/app-layout/inner': {
+            maxDuration: 2,
+          },
+          '/app-route': {
+            maxDuration: 1,
+          },
+          '/app-route-edge': {
+            maxDuration: 2,
+          },
+          '/app-ssr': {
+            maxDuration: 3,
+          },
+          '/app-ssr-edge': {
+            maxDuration: 4,
+          },
+          '/page': {
+            maxDuration: 2,
+          },
+          '/page-ssr': {
+            maxDuration: 3,
+          },
+        },
+        version: 1,
+      })
     }
   })
 })