server: require hook hotfix (#55146)

This PR fixes a bug in the require hook implementation where the variable used might not exist depending on the environment. In order to fix that, we can use the variable used to define the version of React used instead as it is already present and a proxy of the same information.




Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>

packages/next/src/build/index.ts

@@ -1248,7 +1248,6 @@ export default async function build(
           forkOptions: {
             env: {
               ...process.env,
-              __NEXT_PRIVATE_RENDER_RUNTIME: type,
               __NEXT_INCREMENTAL_CACHE_IPC_PORT: ipcPort + '',
               __NEXT_INCREMENTAL_CACHE_IPC_KEY: ipcValidationKey,
               __NEXT_PRIVATE_PREBUNDLED_REACT:
@@ -1256,7 +1255,7 @@ export default async function build(
                   ? config.experimental.serverActions
                     ? 'experimental'
                     : 'next'
-                  : '',
+                  : undefined,
             },
           },
           enableWorkerThreads: config.experimental.workerThreads,

packages/next/src/server/lib/router-server.ts

@@ -6,6 +6,11 @@ import type {
   WorkerUpgradeHandler,
 } from './setup-server-worker'
 
+// This is required before other imports to ensure the require hook is setup.
+import '../node-polyfill-fetch'
+import '../node-environment'
+import '../require-hook'
+
 import url from 'url'
 import path from 'path'
 import loadConfig from '../config'

packages/next/src/server/lib/server-ipc/index.ts

@@ -115,9 +115,12 @@ export const createWorker = async (
         __NEXT_PRIVATE_STANDALONE_CONFIG:
           process.env.__NEXT_PRIVATE_STANDALONE_CONFIG,
         NODE_ENV: process.env.NODE_ENV,
-        __NEXT_PRIVATE_RENDER_RUNTIME: type,
         __NEXT_PRIVATE_PREBUNDLED_REACT:
-          type === 'app' ? (useServerActions ? 'experimental' : 'next') : '',
+          type === 'app'
+            ? useServerActions
+              ? 'experimental'
+              : 'next'
+            : undefined,
         ...(process.env.NEXT_CPU_PROF
           ? { __NEXT_PRIVATE_CPU_PROFILE: `CPU.${type}-renderer` }
           : {}),

packages/next/src/server/require-hook.ts

@@ -122,19 +122,15 @@ mod._resolveFilename = function (
 // that needs to point to the rendering runtime version, it will point to the correct one.
 // This can happen on `pages` when a user requires a dependency that uses next/image for example.
 // This is only needed in production as in development we fallback to the external version.
-if (
-  process.env.NODE_ENV !== 'development' &&
-  process.env.__NEXT_PRIVATE_RENDER_RUNTIME &&
-  !process.env.TURBOPACK
-) {
-  const currentRuntime = `${
-    process.env.__NEXT_PRIVATE_RENDER_RUNTIME === 'pages'
-      ? 'next/dist/compiled/next-server/pages.runtime'
-      : 'next/dist/compiled/next-server/app-page.runtime'
-  }.prod`
-
+if (process.env.NODE_ENV !== 'development' && !process.env.TURBOPACK) {
   mod.prototype.require = function (request: string) {
     if (request.endsWith('.shared-runtime')) {
+      const currentRuntime = `${
+        // this env var is only set in app router
+        !!process.env.__NEXT_PRIVATE_PREBUNDLED_REACT
+          ? 'next/dist/compiled/next-server/app-page.runtime'
+          : 'next/dist/compiled/next-server/pages.runtime'
+      }.prod`
       const base = path.basename(request, '.shared-runtime')
       const camelized = base.replace(/-([a-z])/g, (g) => g[1].toUpperCase())
       const instance = originalRequire.call(this, currentRuntime)