From b6db0a4882e9772cda685eda8cd0502d6c00febe Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Tue, 1 Feb 2022 22:46:07 +0100
Subject: [PATCH] fix problem with HMR when middleware and page reference the
 same node_module (#33873)

fixes https://github.com/vercel/next.js/issues/31827



## Bug

- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `yarn lint`
---
 packages/next/build/webpack-config.ts                | 12 ------------
 .../hmr/node_modules/shared-package/index.js         |  1 +
 .../hmr/node_modules/shared-package/package.json     |  3 +++
 .../middleware/hmr/pages/about/_middleware.js        |  2 ++
 test/integration/middleware/hmr/pages/index.js       |  3 +++
 5 files changed, 9 insertions(+), 12 deletions(-)
 create mode 100644 test/integration/middleware/hmr/node_modules/shared-package/index.js
 create mode 100644 test/integration/middleware/hmr/node_modules/shared-package/package.json

diff --git a/packages/next/build/webpack-config.ts b/packages/next/build/webpack-config.ts
index 647194bfbef8..2c62c2d34243 100644
--- a/packages/next/build/webpack-config.ts
+++ b/packages/next/build/webpack-config.ts
@@ -959,11 +959,6 @@ export default async function getBaseWebpackConfig(
     },
   }
 
-  const nonUserCondition = {
-    include: /node_modules/,
-    exclude: babelIncludeRegexes,
-  }
-
   let webpackConfig: webpack.Configuration = {
     parallelism: Number(process.env.NEXT_WEBPACK_PARALLELISM) || undefined,
     externals: targetWeb
@@ -1256,13 +1251,6 @@ export default async function getBaseWebpackConfig(
             },
           ],
         },
-        {
-          ...nonUserCondition,
-          // Make all non-user modules to be compiled in a single layer
-          // This avoids compiling them mutliple times and avoids module id changes
-          issuerLayer: 'middleware',
-          layer: '',
-        },
         ...(!config.images.disableStaticImages
           ? [
               {
diff --git a/test/integration/middleware/hmr/node_modules/shared-package/index.js b/test/integration/middleware/hmr/node_modules/shared-package/index.js
new file mode 100644
index 000000000000..a8653a9c9264
--- /dev/null
+++ b/test/integration/middleware/hmr/node_modules/shared-package/index.js
@@ -0,0 +1 @@
+module.exports = 42
diff --git a/test/integration/middleware/hmr/node_modules/shared-package/package.json b/test/integration/middleware/hmr/node_modules/shared-package/package.json
new file mode 100644
index 000000000000..1587a669681c
--- /dev/null
+++ b/test/integration/middleware/hmr/node_modules/shared-package/package.json
@@ -0,0 +1,3 @@
+{
+  "version": "1.0.0"
+}
diff --git a/test/integration/middleware/hmr/pages/about/_middleware.js b/test/integration/middleware/hmr/pages/about/_middleware.js
index 66902bd191d7..3146e1d20277 100644
--- a/test/integration/middleware/hmr/pages/about/_middleware.js
+++ b/test/integration/middleware/hmr/pages/about/_middleware.js
@@ -1,5 +1,7 @@
 import { NextResponse } from 'next/server'
+import magicValue from 'shared-package'
 
 export function middleware(request) {
+  if (magicValue !== 42) throw new Error('shared-package problem')
   return NextResponse.rewrite(new URL('/about/a', request.url))
 }
diff --git a/test/integration/middleware/hmr/pages/index.js b/test/integration/middleware/hmr/pages/index.js
index 36f47d633775..fa99cf9c2eb8 100644
--- a/test/integration/middleware/hmr/pages/index.js
+++ b/test/integration/middleware/hmr/pages/index.js
@@ -1,3 +1,6 @@
+import magicValue from 'shared-package'
+if (magicValue !== 42) throw new Error('shared-package problem')
+
 export default function Home() {
   return (
     <div>