From 5f7a329844e9017e5f36fa6fcf950c92d6501199 Mon Sep 17 00:00:00 2001
From: feugy <damien@vercel.com>
Date: Wed, 3 Aug 2022 12:52:06 +0200
Subject: [PATCH] chore: improves implementation to allow any fallbacks

---
 .../build/webpack/plugins/middleware-plugin.ts   | 16 +++++++++++-----
 .../test/index.test.js                           |  5 +----
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/packages/next/build/webpack/plugins/middleware-plugin.ts b/packages/next/build/webpack/plugins/middleware-plugin.ts
index 8a06077879c..f688d4e32e9 100644
--- a/packages/next/build/webpack/plugins/middleware-plugin.ts
+++ b/packages/next/build/webpack/plugins/middleware-plugin.ts
@@ -103,13 +103,22 @@ export default class MiddlewarePlugin {
 
 export async function handleWebpackExtenalForEdgeRuntime({
   request,
+  context,
   contextInfo,
+  getResolve,
 }: {
   request: string
+  context: string
   contextInfo: any
+  getResolve: () => any
 }) {
   if (contextInfo.issuerLayer === 'middleware' && isNodeJsModule(request)) {
-    return `root  globalThis.__import_unsupported('${request}')`
+    // allows user to provide and use their polyfills, as we do with buffer.
+    try {
+      await getResolve()(context, request)
+    } catch {
+      return `root  globalThis.__import_unsupported('${request}')`
+    }
   }
 }
 
@@ -760,8 +769,5 @@ function isProcessEnvMemberExpression(memberExpression: any): boolean {
 }
 
 function isNodeJsModule(moduleName: string) {
-  return (
-    moduleName !== 'buffer' &&
-    require('module').builtinModules.includes(moduleName)
-  )
+  return require('module').builtinModules.includes(moduleName)
 }
diff --git a/test/integration/edge-runtime-module-errors/test/index.test.js b/test/integration/edge-runtime-module-errors/test/index.test.js
index cb31f2bca6c..2906fe6ce0a 100644
--- a/test/integration/edge-runtime-module-errors/test/index.test.js
+++ b/test/integration/edge-runtime-module-errors/test/index.test.js
@@ -599,10 +599,7 @@ describe('Edge runtime code with imports', () => {
     })
 
     it('does not throw in production at runtime', async () => {
-      const { stderr } = await nextBuild(context.appDir, undefined, {
-        stderr: true,
-      })
-      expect(stderr).not.toContain(getUnsupportedModuleWarning(moduleName))
+      await nextBuild(context.appDir, undefined, { stderr: true })
       context.app = await nextStart(context.appDir, context.appPort, appOption)
       const res = await fetchViaHTTP(context.appPort, url)
       expect(res.status).toBe(200)