From 666fe5a6f54c1134fe80054adcf6aac4aec1ec58 Mon Sep 17 00:00:00 2001
From: Michal Piechowiak <misiek.piechowiak@gmail.com>
Date: Mon, 26 Aug 2024 17:31:39 +0200
Subject: [PATCH] fix: handle cases of chunked middleware (#2574)

* test: make middleware fixture produce chunked middleware

* fix: handle cases of chunked middleware
---
 src/build/functions/edge.ts              | 2 +-
 tests/fixtures/middleware/next.config.js | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/build/functions/edge.ts b/src/build/functions/edge.ts
index 4c95ad1353..6d9919c11f 100644
--- a/src/build/functions/edge.ts
+++ b/src/build/functions/edge.ts
@@ -125,7 +125,7 @@ const copyHandlerDependencies = async (
     const entrypoint = await readFile(join(srcDir, file), 'utf8')
     parts.push(`;// Concatenated file: ${file} \n`, entrypoint)
   }
-  const exports = `export default _ENTRIES["middleware_${name}"].default;`
+  const exports = `const middlewareEntryKey = Object.keys(_ENTRIES).find(entryKey => entryKey.startsWith("middleware_${name}")); export default _ENTRIES[middlewareEntryKey].default;`
   await mkdir(dirname(join(destDir, `server/${name}.js`)), { recursive: true })
 
   await writeFile(join(destDir, `server/${name}.js`), [...parts, exports].join('\n'))
diff --git a/tests/fixtures/middleware/next.config.js b/tests/fixtures/middleware/next.config.js
index 9d94510be1..28875fd694 100644
--- a/tests/fixtures/middleware/next.config.js
+++ b/tests/fixtures/middleware/next.config.js
@@ -4,6 +4,13 @@ const nextConfig = {
   eslint: {
     ignoreDuringBuilds: true,
   },
+  webpack: (config) => {
+    // this is a trigger to generate multiple `.next/server/middleware-[hash].js` files instead of
+    // single `.next/server/middleware.js` file
+    config.optimization.splitChunks.maxSize = 100_000
+
+    return config
+  },
 }
 
 module.exports = nextConfig