fix(edge-runtime): undefined global in edge runtime.

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

@@ -16,14 +16,9 @@ export default function middlewareLoader(this: any) {
   }
 
   return `
-        import { adapter } from 'next/dist/server/web/adapter'
+        import { adapter, enhanceGlobals } from 'next/dist/server/web/adapter'
 
-        // The condition is true when the "process" module is provided
-        if (process !== global.process) {
-          // prefer local process but global.process has correct "env"
-          process.env = global.process.env;
-          global.process = process;
-        }
+        enhanceGlobals()
 
         var mod = require(${stringifiedPagePath})
         var handler = mod.middleware || mod.default;

packages/next/build/webpack/loaders/next-middleware-loader.ts

@@ -27,14 +27,9 @@ export default function middlewareLoader(this: any) {
   }
 
   return `
-        import { adapter, blockUnallowedResponse } from 'next/dist/server/web/adapter'
+        import { adapter, blockUnallowedResponse, enhanceGlobals } from 'next/dist/server/web/adapter'
 
-        // The condition is true when the "process" module is provided
-        if (process !== global.process) {
-          // prefer local process but global.process has correct "env"
-          process.env = global.process.env;
-          global.process = process;
-        }
+        enhanceGlobals()
 
         var mod = require(${stringifiedPagePath})
         var handler = mod.middleware || mod.default;

packages/next/build/webpack/plugins/middleware-plugin.ts

@@ -104,7 +104,7 @@ export async function handleWebpackExtenalForEdgeRuntime({
   contextInfo: any
 }) {
   if (contextInfo.issuerLayer === 'middleware' && isNodeJsModule(request)) {
-    return `root  __import_unsupported('${request}')`
+    return `root  globalThis.__import_unsupported('${request}')`
   }
 }
 

packages/next/server/dev/next-dev-server.ts

@@ -797,7 +797,7 @@ export default class DevServer extends Server {
         const frames = parseStack(err.stack!)
         const frame = frames.find(
           ({ file }) =>
-            !file?.startsWith('eval') && !file?.includes('sandbox/context')
+            !file?.startsWith('eval') && !file?.includes('web/adapter')
         )!
 
         if (frame.lineNumber && frame?.file) {

packages/next/server/web/adapter.ts

@@ -162,6 +162,50 @@ export function blockUnallowedResponse(
   })
 }
 
+export function enhanceGlobals() {
+  // The condition is true when the "process" module is provided
+  if (process !== global.process) {
+    // prefer local process but global.process has correct "env"
+    process.env = global.process.env
+    global.process = process
+  }
+
+  // to allow building code that import but does not use node.js modules,
+  // webpack will expect this function to exist in global scope
+  Object.defineProperty(globalThis, '__import_unsupported', {
+    value: __import_unsupported,
+    enumerable: false,
+    configurable: false,
+  })
+}
+
+function __import_unsupported(moduleName: string) {
+  const proxy: any = new Proxy(function () {}, {
+    get(_obj, prop) {
+      if (prop === 'then') {
+        return {}
+      }
+      throw new Error(getUnsupportedModuleErrorMessage(moduleName))
+    },
+    construct() {
+      throw new Error(getUnsupportedModuleErrorMessage(moduleName))
+    },
+    apply(_target, _this, args) {
+      if (typeof args[0] === 'function') {
+        return args[0](proxy)
+      }
+      throw new Error(getUnsupportedModuleErrorMessage(moduleName))
+    },
+  })
+  return new Proxy({}, { get: () => proxy })
+}
+
+function getUnsupportedModuleErrorMessage(module: string) {
+  // warning: if you change these messages, you must adjust how react-dev-overlay's middleware detects modules not found
+  return `The edge runtime does not support Node.js '${module}' module.
+Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime`
+}
+
 class NextRequestHint extends NextRequest {
   sourcePage: string
 

packages/next/server/web/sandbox/context.ts

@@ -129,29 +129,6 @@ async function createModuleContext(options: ModuleContextOptions) {
         return fn()
       }
 
-      context.__import_unsupported = function __import_unsupported(
-        moduleName: string
-      ) {
-        const proxy: any = new Proxy(function () {}, {
-          get(_obj, prop) {
-            if (prop === 'then') {
-              return {}
-            }
-            throw new Error(getUnsupportedModuleErrorMessage(moduleName))
-          },
-          construct() {
-            throw new Error(getUnsupportedModuleErrorMessage(moduleName))
-          },
-          apply(_target, _this, args) {
-            if (args[0] instanceof Function) {
-              return args[0](proxy)
-            }
-            throw new Error(getUnsupportedModuleErrorMessage(moduleName))
-          },
-        })
-        return new Proxy({}, { get: () => proxy })
-      }
-
       context.__next_webassembly_compile__ =
         function __next_webassembly_compile__(fn: Function) {
           const key = fn.toString()
@@ -354,9 +331,3 @@ function decorateUnhandledError(error: any) {
     decorateServerError(error, 'edge-server')
   }
 }
-
-function getUnsupportedModuleErrorMessage(module: string) {
-  // warning: if you change these messages, you must adjust how react-dev-overlay's middleware detects modules not found
-  return `The edge runtime does not support Node.js '${module}' module.
-Learn More: https://nextjs.org/docs/messages/node-module-in-edge-runtime`
-}