Ensure component load order

packages/next/build/index.ts

@@ -680,7 +680,8 @@ export default async function build(
                         )
                         return staticCheckWorkers.isPageStatic(
                           page,
-                          serverBundle,
+                          distDir,
+                          isLikeServerless,
                           runtimeEnvConfig,
                           config.i18n?.locales,
                           config.i18n?.defaultLocale,

packages/next/build/utils.ts

@@ -31,6 +31,7 @@ import { normalizeLocalePath } from '../next-server/lib/i18n/normalize-locale-pa
 import * as Log from './output/log'
 import opentelemetryApi from '@opentelemetry/api'
 import { tracer, traceAsyncFn } from './tracer'
+import { loadComponents } from '../next-server/server/load-components'
 
 const fileGzipStats: { [k: string]: Promise<number> } = {}
 const fsStatGzip = (file: string) => {
@@ -713,7 +714,8 @@ export async function buildStaticPaths(
 
 export async function isPageStatic(
   page: string,
-  serverBundle: string,
+  distDir: string,
+  serverless: boolean,
   runtimeEnvConfig: any,
   locales?: string[],
   defaultLocale?: string,
@@ -742,8 +744,9 @@ export async function isPageStatic(
             require('../next-server/lib/runtime-config').setConfig(
               runtimeEnvConfig
             )
-            const mod = await require(serverBundle)
-            const Comp = await (mod.default || mod)
+            const components = await loadComponents(distDir, page, serverless)
+            const mod = components.ComponentMod
+            const Comp = mod.default || mod
 
             if (
               !Comp ||

packages/next/build/webpack/loaders/next-serverless-loader/index.ts

@@ -138,6 +138,8 @@ const nextServerlessLoader: webpack.loader.Loader = function () {
       }
       import { getPageHandler } from 'next/dist/build/webpack/loaders/next-serverless-loader/page-handler'
 
+      const documentModule = require("${absoluteDocumentPath}")
+
       const appMod = require('${absoluteAppPath}')
       let App = appMod.default || appMod.then && appMod.then(mod => mod.default);
 
@@ -163,7 +165,7 @@ const nextServerlessLoader: webpack.loader.Loader = function () {
         pageComponent: Component,
         pageConfig: config,
         appModule: App,
-        documentModule: require("${absoluteDocumentPath}"),
+        documentModule: documentModule,
         errorModule: require("${absoluteErrorPath}"),
         notFoundModule: ${
           absolute404Path ? `require("${absolute404Path}")` : undefined

packages/next/next-server/server/config.ts

@@ -2,6 +2,7 @@ import chalk from 'chalk'
 import findUp from 'next/dist/compiled/find-up'
 import { basename, extname } from 'path'
 import * as Log from '../../build/output/log'
+import { hasNextSupport } from '../../telemetry/ci-info'
 import { CONFIG_FILE } from '../lib/constants'
 import { execOnce } from '../lib/utils'
 import { defaultConfig, normalizeConfig } from './config-shared'
@@ -443,6 +444,10 @@ export default async function loadConfig(
       )
     }
 
+    if (hasNextSupport) {
+      userConfig.target = process.env.NEXT_PRIVATE_TARGET || 'server'
+    }
+
     return assignDefaults({
       configOrigin: CONFIG_FILE,
       configFile: path,

packages/next/next-server/server/load-components.ts

@@ -32,6 +32,7 @@ export type LoadComponentsReturnType = {
   getStaticProps?: GetStaticProps
   getStaticPaths?: GetStaticPaths
   getServerSideProps?: GetServerSideProps
+  ComponentMod: any
 }
 
 export async function loadComponents(
@@ -54,14 +55,13 @@ export async function loadComponents(
       getStaticProps,
       getStaticPaths,
       getServerSideProps,
+      ComponentMod: Component,
     } as LoadComponentsReturnType
   }
 
-  const [DocumentMod, AppMod, ComponentMod] = await Promise.all([
-    requirePage('/_document', distDir, serverless),
-    requirePage('/_app', distDir, serverless),
-    requirePage(pathname, distDir, serverless),
-  ])
+  const DocumentMod = await requirePage('/_document', distDir, serverless)
+  const AppMod = await requirePage('/_app', distDir, serverless)
+  const ComponentMod = await requirePage(pathname, distDir, serverless)
 
   const [
     buildManifest,
@@ -86,6 +86,7 @@ export async function loadComponents(
     buildManifest,
     reactLoadableManifest,
     pageConfig: ComponentMod.config || {},
+    ComponentMod,
     getServerSideProps,
     getStaticProps,
     getStaticPaths,

test/integration/required-server-files/lib/config.js

@@ -0,0 +1,13 @@
+let curConfig
+
+const idk = Math.random()
+
+export default () => {
+  console.log('returning config', idk, curConfig)
+  return curConfig
+}
+
+export function setConfig(configValue) {
+  curConfig = configValue
+  console.log('set config', idk, configValue)
+}

test/integration/required-server-files/next.config.js

@@ -1,4 +1,6 @@
 module.exports = {
+  // ensure incorrect target is overridden by env
+  target: 'serverless',
   rewrites() {
     return [
       {

test/integration/required-server-files/pages/_app.js

@@ -0,0 +1,7 @@
+import { setConfig } from '../lib/config'
+
+setConfig({ hello: 'world' })
+
+export default function MyApp({ Component, pageProps }) {
+  return <Component {...pageProps} />
+}

test/integration/required-server-files/pages/index.js

@@ -1,4 +1,11 @@
 import { useRouter } from 'next/router'
+import getConfig from '../lib/config'
+
+const localConfig = getConfig()
+
+if (localConfig.hello !== 'world') {
+  throw new Error('oof import order is wrong, _app comes first')
+}
 
 export const getServerSideProps = ({ req }) => {
   return {

test/integration/required-server-files/test/index.test.js

@@ -25,7 +25,11 @@ let errors = []
 describe('Required Server Files', () => {
   beforeAll(async () => {
     await fs.remove(join(appDir, '.next'))
-    await nextBuild(appDir)
+    await nextBuild(appDir, undefined, {
+      env: {
+        NOW_BUILDER: '1',
+      },
+    })
 
     buildId = await fs.readFile(join(appDir, '.next/BUILD_ID'), 'utf8')
     requiredFilesManifest = await fs.readJSON(
@@ -88,6 +92,8 @@ describe('Required Server Files', () => {
       console.log('checking', file)
       expect(await fs.exists(join(appDir, file))).toBe(true)
     }
+
+    expect(await fs.exists(join(appDir, '.next/server'))).toBe(true)
   })
 
   it('should render SSR page correctly', async () => {