Support preferredRegion and Support runtime/preferredRegion on layouts

packages/next/src/build/analysis/get-page-static-info.ts

@@ -35,6 +35,7 @@ export interface MiddlewareMatcher {
 
 export interface PageStaticInfo {
   runtime?: ServerRuntime
+  preferredRegion?: string | string[]
   ssg?: boolean
   ssr?: boolean
   rsc?: RSCModuleType
@@ -81,10 +82,12 @@ function checkExports(swcAST: any): {
   ssr: boolean
   ssg: boolean
   runtime?: string
+  preferredRegion?: string | string[]
 } {
   if (Array.isArray(swcAST?.body)) {
     try {
       let runtime: string | undefined
+      let preferredRegion: string | string[] | undefined
       let ssr: boolean = false
       let ssg: boolean = false
 
@@ -97,6 +100,22 @@ function checkExports(swcAST: any): {
             if (declaration.id.value === 'runtime') {
               runtime = declaration.init.value
             }
+
+            if (declaration.id.value === 'preferredRegion') {
+              if (declaration.init.type === 'ArrayExpression') {
+                const elements: string[] = []
+                for (const element of declaration.init.elements) {
+                  const { expression } = element
+                  if (expression.type !== 'StringLiteral') {
+                    continue
+                  }
+                  elements.push(expression.value)
+                }
+                preferredRegion = elements
+              } else {
+                preferredRegion = declaration.init.value
+              }
+            }
           }
         }
 
@@ -137,7 +156,7 @@ function checkExports(swcAST: any): {
         }
       }
 
-      return { ssr, ssg, runtime }
+      return { ssr, ssg, runtime, preferredRegion }
     } catch (err) {}
   }
 
@@ -322,12 +341,12 @@ export async function getPageStaticInfo(params: {
 
   const fileContent = (await tryToReadFile(pageFilePath, !isDev)) || ''
   if (
-    /runtime|getStaticProps|getServerSideProps|export const config/.test(
+    /runtime|preferredRegion|getStaticProps|getServerSideProps|export const config/.test(
       fileContent
     )
   ) {
     const swcAST = await parseModule(pageFilePath, fileContent)
-    const { ssg, ssr, runtime } = checkExports(swcAST)
+    const { ssg, ssr, runtime, preferredRegion } = checkExports(swcAST)
     const rsc = getRSCModuleInformation(fileContent).type
 
     // default / failsafe value for config
@@ -420,6 +439,7 @@ export async function getPageStaticInfo(params: {
       rsc,
       ...(middlewareConfig && { middleware: middlewareConfig }),
       ...(resolvedRuntime && { runtime: resolvedRuntime }),
+      preferredRegion,
     }
   }
 

packages/next/src/build/entries.ts

@@ -7,12 +7,13 @@ import type { webpack } from 'next/dist/compiled/webpack/webpack'
 import type {
   MiddlewareConfig,
   MiddlewareMatcher,
+  PageStaticInfo,
 } from './analysis/get-page-static-info'
 import type { LoadedEnvFiles } from '@next/env'
 import type { AppLoaderOptions } from './webpack/loaders/next-app-loader'
 
 import chalk from 'next/dist/compiled/chalk'
-import { posix, join } from 'path'
+import { posix, join, dirname } from 'path'
 import { stringify } from 'querystring'
 import {
   PAGES_DIR_ALIAS,
@@ -50,6 +51,83 @@ import { encodeMatchers } from './webpack/loaders/next-middleware-loader'
 import { EdgeFunctionLoaderOptions } from './webpack/loaders/next-edge-function-loader'
 import { isAppRouteRoute } from '../lib/is-app-route-route'
 import { normalizeMetadataRoute } from '../lib/metadata/get-metadata-route'
+import { fileExists } from '../lib/file-exists'
+
+export async function getStaticInfoIncludingLayouts({
+  isInsideAppDir,
+  pageExtensions,
+  pageFilePath,
+  appDir,
+  config,
+  isDev,
+  page,
+}: {
+  isInsideAppDir: boolean
+  pageExtensions: string[]
+  pageFilePath: string
+  appDir: string | undefined
+  config: NextConfigComplete
+  isDev: boolean | undefined
+  page: string
+}): Promise<PageStaticInfo> {
+  const pageStaticInfo = await getPageStaticInfo({
+    nextConfig: config,
+    pageFilePath,
+    isDev,
+    page,
+    pageType: isInsideAppDir ? 'app' : 'pages',
+  })
+
+  const staticInfo: PageStaticInfo = isInsideAppDir
+    ? {
+        // TODO-APP: Remove the rsc key altogether. It's no longer required.
+        rsc: 'server',
+      }
+    : pageStaticInfo
+
+  if (isInsideAppDir) {
+    const layoutFiles = []
+    const potentialLayoutFiles = pageExtensions.map((ext) => 'layout.' + ext)
+    let dir = dirname(pageFilePath)
+    while (dir !== appDir) {
+      for (const potentialLayoutFile of potentialLayoutFiles) {
+        const layoutFile = join(dir, potentialLayoutFile)
+        if (!(await fileExists(layoutFile))) {
+          continue
+        }
+        layoutFiles.unshift(layoutFile)
+      }
+      // Walk up the directory tree
+      dir = join(dir, '..')
+    }
+
+    for (const layoutFile of layoutFiles) {
+      const layoutStaticInfo = await getPageStaticInfo({
+        nextConfig: config,
+        pageFilePath: layoutFile,
+        isDev,
+        page,
+        pageType: isInsideAppDir ? 'app' : 'pages',
+      })
+
+      // Only runtime is relevant here.
+      if (layoutStaticInfo.runtime) {
+        staticInfo.runtime = layoutStaticInfo.runtime
+      }
+      if (layoutStaticInfo.preferredRegion) {
+        staticInfo.preferredRegion = layoutStaticInfo.preferredRegion
+      }
+    }
+
+    if (pageStaticInfo.runtime) {
+      staticInfo.runtime = pageStaticInfo.runtime
+    }
+    if (pageStaticInfo.preferredRegion) {
+      staticInfo.preferredRegion = pageStaticInfo.preferredRegion
+    }
+  }
+  return staticInfo
+}
 
 type ObjectValue<T> = T extends { [key: string]: infer V } ? V : never
 
@@ -204,6 +282,7 @@ export function getEdgeServerEntry(opts: {
   pagesType: 'app' | 'pages' | 'root'
   appDirLoader?: string
   hasInstrumentationHook?: boolean
+  preferredRegion: string | string[] | undefined
 }) {
   if (
     opts.pagesType === 'app' &&
@@ -215,6 +294,7 @@ export function getEdgeServerEntry(opts: {
       page: opts.page,
       appDirLoader: Buffer.from(opts.appDirLoader || '').toString('base64'),
       nextConfigOutput: opts.config.output,
+      preferredRegion: opts.preferredRegion,
     }
 
     return {
@@ -240,6 +320,7 @@ export function getEdgeServerEntry(opts: {
       absolutePagePath: opts.absolutePagePath,
       page: opts.page,
       rootDir: opts.rootDir,
+      preferredRegion: opts.preferredRegion,
     }
 
     return `next-edge-function-loader?${stringify(loaderParams)}!`
@@ -268,6 +349,7 @@ export function getEdgeServerEntry(opts: {
     sriEnabled: !opts.isDev && !!opts.config.experimental.sri?.algorithm,
     incrementalCacheHandlerPath:
       opts.config.experimental.incrementalCacheHandlerPath,
+    preferredRegion: opts.preferredRegion,
   }
 
   return {
@@ -426,12 +508,14 @@ export async function createEntrypoints(
         (absolutePagePath.startsWith(APP_DIR_ALIAS) ||
           absolutePagePath.startsWith(appDir))
 
-      const staticInfo = await getPageStaticInfo({
-        nextConfig: config,
+      const staticInfo: PageStaticInfo = await getStaticInfoIncludingLayouts({
+        isInsideAppDir,
+        pageExtensions,
         pageFilePath,
+        appDir,
+        config,
         isDev,
         page,
-        pageType: isInsideAppDir ? 'app' : 'pages',
       })
 
       const isServerComponent =
@@ -470,6 +554,7 @@ export async function createEntrypoints(
               pageExtensions,
               assetPrefix: config.assetPrefix,
               nextConfigOutput: config.output,
+              preferredRegion: staticInfo.preferredRegion,
             })
           } else {
             if (isInstrumentationHookFile(page) && pagesType === 'root') {
@@ -496,6 +581,9 @@ export async function createEntrypoints(
               pageExtensions,
               assetPrefix: config.assetPrefix,
               nextConfigOutput: config.output,
+              // This isn't used with edge as it needs to be set on the entry module, which will be the `edgeServerEntry` instead.
+              // Still passing it here for consistency.
+              preferredRegion: staticInfo.preferredRegion,
             }).import
           }
           const normalizedServerBundlePath =
@@ -513,6 +601,7 @@ export async function createEntrypoints(
             middleware: staticInfo?.middleware,
             pagesType,
             appDirLoader,
+            preferredRegion: staticInfo.preferredRegion,
           })
         },
       })

packages/next/src/build/webpack/loaders/get-module-build-info.ts

@@ -36,6 +36,7 @@ export interface RSCMeta {
 export interface RouteMeta {
   page: string
   absolutePagePath: string
+  preferredRegion: string | string[] | undefined
 }
 
 export interface EdgeMiddlewareMeta {

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

@@ -27,6 +27,7 @@ export type AppLoaderOptions = {
   pagePath: string
   appDir: string
   appPaths: readonly string[] | null
+  preferredRegion: string | string[] | undefined
   pageExtensions: string[]
   assetPrefix: string
   rootDir?: string
@@ -421,13 +422,15 @@ const nextAppLoader: AppLoader = async function nextAppLoader() {
     tsconfigPath,
     isDev,
     nextConfigOutput,
+    preferredRegion,
   } = loaderOptions
 
   const buildInfo = getModuleBuildInfo((this as any)._module)
   const page = name.replace(/^app/, '')
   buildInfo.route = {
     page,
     absolutePagePath: createAbsolutePath(appDir, pagePath),
+    preferredRegion,
   }
 
   const extensions = pageExtensions.map((extension) => `.${extension}`)

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

@@ -7,6 +7,7 @@ export type EdgeAppRouteLoaderQuery = {
   absolutePagePath: string
   page: string
   appDirLoader: string
+  preferredRegion: string | string[] | undefined
   nextConfigOutput: NextConfig['output']
 }
 
@@ -15,6 +16,7 @@ const EdgeAppRouteLoader: webpack.LoaderDefinitionFunction<EdgeAppRouteLoaderQue
     const {
       page,
       absolutePagePath,
+      preferredRegion,
       appDirLoader: appDirLoaderBase64 = '',
     } = this.getOptions()
 
@@ -33,6 +35,7 @@ const EdgeAppRouteLoader: webpack.LoaderDefinitionFunction<EdgeAppRouteLoaderQue
     buildInfo.route = {
       page,
       absolutePagePath,
+      preferredRegion,
     }
 
     const stringifiedPagePath = stringifyRequest(this, absolutePagePath)

packages/next/src/build/webpack/loaders/next-edge-function-loader.ts

@@ -1,23 +1,35 @@
+import type webpack from 'webpack'
 import { getModuleBuildInfo } from './get-module-build-info'
 import { stringifyRequest } from '../stringify-request'
 
 export type EdgeFunctionLoaderOptions = {
   absolutePagePath: string
   page: string
   rootDir: string
+  preferredRegion: string | string[] | undefined
 }
 
-export default function middlewareLoader(this: any) {
-  const { absolutePagePath, page, rootDir }: EdgeFunctionLoaderOptions =
-    this.getOptions()
-  const stringifiedPagePath = stringifyRequest(this, absolutePagePath)
-  const buildInfo = getModuleBuildInfo(this._module)
-  buildInfo.nextEdgeApiFunction = {
-    page: page || '/',
-  }
-  buildInfo.rootDir = rootDir
+const nextEdgeFunctionLoader: webpack.LoaderDefinitionFunction<EdgeFunctionLoaderOptions> =
+  function nextEdgeFunctionLoader(this) {
+    const {
+      absolutePagePath,
+      page,
+      rootDir,
+      preferredRegion,
+    }: EdgeFunctionLoaderOptions = this.getOptions()
+    const stringifiedPagePath = stringifyRequest(this, absolutePagePath)
+    const buildInfo = getModuleBuildInfo(this._module as any)
+    buildInfo.route = {
+      page: page || '/',
+      absolutePagePath,
+      preferredRegion,
+    }
+    buildInfo.nextEdgeApiFunction = {
+      page: page || '/',
+    }
+    buildInfo.rootDir = rootDir
 
-  return `
+    return `
         import { adapter, enhanceGlobals } from 'next/dist/esm/server/web/adapter'
         import {IncrementalCache} from 'next/dist/esm/server/lib/incremental-cache'
 
@@ -39,4 +51,6 @@ export default function middlewareLoader(this: any) {
           })
         }
     `
-}
+  }
+
+export default nextEdgeFunctionLoader