From df76f6633fe192e04b88ace62a00ccc9bb833d86 Mon Sep 17 00:00:00 2001
From: Jimmy Lai <laijimmy0@gmail.com>
Date: Mon, 11 Sep 2023 14:23:02 +0200
Subject: [PATCH] server: remove turbopack-specific code when compiling with
 webpack (#55226)

This PR tweaks the webpack config so that when we compile user code with webpack, we remove all branches of code that are guarded with `process.env.TURBOPACK`. I noticed that the bundle runtime was not tree-shaken correctly, this fixes that.
---
 packages/next/src/build/webpack-config.ts | 1 +
 packages/next/webpack.config.js           | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/next/src/build/webpack-config.ts b/packages/next/src/build/webpack-config.ts
index d1b7487618fe2..dbc805edaf1fd 100644
--- a/packages/next/src/build/webpack-config.ts
+++ b/packages/next/src/build/webpack-config.ts
@@ -371,6 +371,7 @@ export function getDefineEnv({
           'global.GENTLY': JSON.stringify(false),
         }
       : undefined),
+    'process.env.TURBOPACK': JSON.stringify(false),
   }
 }
 
diff --git a/packages/next/webpack.config.js b/packages/next/webpack.config.js
index 8e7c3063fa5ed..83fe9d3009877 100644
--- a/packages/next/webpack.config.js
+++ b/packages/next/webpack.config.js
@@ -131,6 +131,7 @@ module.exports = ({ dev, turbo }) => {
           dev ? 'development' : 'production'
         ),
         'process.env.NEXT_RUNTIME': JSON.stringify('nodejs'),
+        ...(!dev ? { 'process.env.TURBOPACK': JSON.stringify(turbo) } : {}),
       }),
       !!process.env.ANALYZE &&
         new BundleAnalyzerPlugin({