vercel · gnoff · Oct 27, 2025 · Oct 23, 2025
diff --git a/crates/next-core/src/next_edge/context.rs b/crates/next-core/src/next_edge/context.rs
@@ -153,9 +153,9 @@ pub async fn get_edge_resolve_options_context(
         custom_conditions.push(rcstr!("react-server"));
     };
 
-    if *next_config.enable_cache_components().await? {
-        custom_conditions.push(rcstr!("next-js"));
-    };
+    // Edge runtime is disabled for projects with Cache Components enabled except for Middleware
+    // but Middleware doesn't have all Next.js APIs so we omit the "next-js" condition for all edge
+    // entrypoints
 
     let resolve_options_context = ResolveOptionsContext {
         enable_node_modules: Some(project_path.root().owned().await?),

diff --git a/crates/next-core/src/next_server/context.rs b/crates/next-core/src/next_server/context.rs
@@ -214,7 +214,10 @@ pub async fn get_server_resolve_options_context(
         custom_conditions.push(rcstr!("react-server"));
     };
 
-    if *next_config.enable_cache_components().await? {
+    if *next_config.enable_cache_components().await?
+        // Middleware shouldn't use the "next-js" condition because it doesn't have all Next.js APIs available
+        && !matches!(ty, ServerContextType::Middleware { .. } |  ServerContextType::Instrumentation { .. })
+    {
         custom_conditions.push(rcstr!("next-js"));
     };
 

diff --git a/packages/next/src/build/webpack-config.ts b/packages/next/src/build/webpack-config.ts
@@ -687,7 +687,6 @@ export default async function getBaseWebpackConfig(
     : distDir
 
   const conditionNames = [
-    ...(config.cacheComponents === true ? ['next-js'] : []),
     ...(isEdgeServer ? [edgeConditionName] : []),
     // inherits Webpack's default conditions
     '...',
@@ -1389,6 +1388,17 @@ export default async function getBaseWebpackConfig(
     },
     module: {
       rules: [
+        {
+          issuerLayer: {
+            not: [WEBPACK_LAYERS.middleware, WEBPACK_LAYERS.instrument],
+          },
+          resolve: {
+            conditionNames: [
+              config.cacheComponents ? 'next-js' : '',
+              '...',
+            ].filter(Boolean) as string[],
+          },
+        },
         // Alias server-only and client-only to proper exports based on bundling layers
         {
           issuerLayer: {

diff --git a/test/e2e/app-dir/next-condition/.gitignore → ...ition/fixtures/instrumentation/.gitignore b/test/e2e/app-dir/next-condition/.gitignore → ...ition/fixtures/instrumentation/.gitignore
diff --git a/...e2e/app-dir/next-condition/app/layout.tsx → ...n/fixtures/instrumentation/app/layout.tsx b/...e2e/app-dir/next-condition/app/layout.tsx → ...n/fixtures/instrumentation/app/layout.tsx
diff --git a/test/e2e/app-dir/next-condition/fixtures/instrumentation/app/page.tsx b/test/e2e/app-dir/next-condition/fixtures/instrumentation/app/page.tsx
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>Hello World</div>
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/instrumentation/instrumentation.ts b/test/e2e/app-dir/next-condition/fixtures/instrumentation/instrumentation.ts
@@ -0,0 +1,13 @@
+import CJSExportsDefault from 'my-cjs-package/exports'
+import ExternalCJSExportsDefault from 'my-external-cjs-package/exports'
+import ESMExportsDefault from 'my-esm-package/exports'
+import ExternalESMExportsDefault from 'my-external-esm-package/exports'
+
+export function register() {
+  console.log('==== REGISTER START ====')
+  console.log('CJSExportsDefault:', CJSExportsDefault)
+  console.log('ExternalCJSExportsDefault:', ExternalCJSExportsDefault)
+  console.log('ESMExportsDefault:', ESMExportsDefault)
+  console.log('ExternalESMExportsDefault:', ExternalESMExportsDefault)
+  console.log('==== REGISTER END ====')
+}
diff --git a/...e2e/app-dir/next-condition/next.config.js → ...n/fixtures/instrumentation/next.config.js b/...e2e/app-dir/next-condition/next.config.js → ...n/fixtures/instrumentation/next.config.js
diff --git a/test/e2e/app-dir/next-condition/fixtures/instrumentation/package.json b/test/e2e/app-dir/next-condition/fixtures/instrumentation/package.json
@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "my-cjs-package": "file:./sym-linked-packages/my-cjs-package",
+    "my-esm-package": "file:./sym-linked-packages/my-esm-package",
+    "my-external-cjs-package": "file:./sym-linked-packages/my-external-cjs-package",
+    "my-external-esm-package": "file:./sym-linked-packages/my-external-esm-package"
+  }
+}
diff --git a/.../e2e/app-dir/next-condition/packages.d.ts → ...on/fixtures/instrumentation/packages.d.ts b/.../e2e/app-dir/next-condition/packages.d.ts → ...on/fixtures/instrumentation/packages.d.ts
diff --git a/test/e2e/app-dir/next-condition/fixtures/instrumentation/sym-linked-packages b/test/e2e/app-dir/next-condition/fixtures/instrumentation/sym-linked-packages
@@ -0,0 +1 @@
+../../packages
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/.gitignore b/test/e2e/app-dir/next-condition/fixtures/middleware/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/app/layout.tsx b/test/e2e/app-dir/next-condition/fixtures/middleware/app/layout.tsx
@@ -0,0 +1,9 @@
+export default function Root({ children }: { children: React.ReactNode }) {
+  return (
+    <html>
+      <body>
+        <main>{children}</main>
+      </body>
+    </html>
+  )
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/app/page.tsx b/test/e2e/app-dir/next-condition/fixtures/middleware/app/page.tsx
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>Hello World</div>
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/middleware.ts b/test/e2e/app-dir/next-condition/fixtures/middleware/middleware.ts
@@ -0,0 +1,15 @@
+import CJSExportsDefault from 'my-cjs-package/exports'
+import ExternalCJSExportsDefault from 'my-external-cjs-package/exports'
+import ESMExportsDefault from 'my-esm-package/exports'
+import ExternalESMExportsDefault from 'my-external-esm-package/exports'
+
+export default async function proxy(req: Request) {
+  if (!req.url.includes('/_next/')) {
+    console.log('==== MIDDLEWARE START ====')
+    console.log('CJSExportsDefault:', CJSExportsDefault)
+    console.log('ExternalCJSExportsDefault:', ExternalCJSExportsDefault)
+    console.log('ESMExportsDefault:', ESMExportsDefault)
+    console.log('ExternalESMExportsDefault:', ExternalESMExportsDefault)
+    console.log('==== MIDDLEWARE END ====')
+  }
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/next.config.js b/test/e2e/app-dir/next-condition/fixtures/middleware/next.config.js
@@ -0,0 +1,12 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+
+const nextConfig = {
+  serverExternalPackages: [
+    'my-external-esm-package',
+    'my-external-cjs-package',
+  ],
+}
+
+module.exports = nextConfig
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/package.json b/test/e2e/app-dir/next-condition/fixtures/middleware/package.json
@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "my-cjs-package": "file:./sym-linked-packages/my-cjs-package",
+    "my-esm-package": "file:./sym-linked-packages/my-esm-package",
+    "my-external-cjs-package": "file:./sym-linked-packages/my-external-cjs-package",
+    "my-external-esm-package": "file:./sym-linked-packages/my-external-esm-package"
+  }
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/packages.d.ts b/test/e2e/app-dir/next-condition/fixtures/middleware/packages.d.ts
@@ -0,0 +1,8 @@
+declare module 'my-cjs-package/exports'
+declare module 'my-cjs-package/imports'
+declare module 'my-esm-package/exports'
+declare module 'my-esm-package/imports'
+declare module 'my-external-cjs-package/exports'
+declare module 'my-external-cjs-package/imports'
+declare module 'my-external-esm-package/exports'
+declare module 'my-external-esm-package/imports'
diff --git a/test/e2e/app-dir/next-condition/fixtures/middleware/sym-linked-packages b/test/e2e/app-dir/next-condition/fixtures/middleware/sym-linked-packages
@@ -0,0 +1 @@
+../../packages
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/.gitignore b/test/e2e/app-dir/next-condition/fixtures/proxy/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/app/layout.tsx b/test/e2e/app-dir/next-condition/fixtures/proxy/app/layout.tsx
@@ -0,0 +1,9 @@
+export default function Root({ children }: { children: React.ReactNode }) {
+  return (
+    <html>
+      <body>
+        <main>{children}</main>
+      </body>
+    </html>
+  )
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/app/page.tsx b/test/e2e/app-dir/next-condition/fixtures/proxy/app/page.tsx
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div>Hello World</div>
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/next.config.js b/test/e2e/app-dir/next-condition/fixtures/proxy/next.config.js
@@ -0,0 +1,12 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+
+const nextConfig = {
+  serverExternalPackages: [
+    'my-external-esm-package',
+    'my-external-cjs-package',
+  ],
+}
+
+module.exports = nextConfig
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/package.json b/test/e2e/app-dir/next-condition/fixtures/proxy/package.json
@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "my-cjs-package": "file:./sym-linked-packages/my-cjs-package",
+    "my-esm-package": "file:./sym-linked-packages/my-esm-package",
+    "my-external-cjs-package": "file:./sym-linked-packages/my-external-cjs-package",
+    "my-external-esm-package": "file:./sym-linked-packages/my-external-esm-package"
+  }
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/packages.d.ts b/test/e2e/app-dir/next-condition/fixtures/proxy/packages.d.ts
@@ -0,0 +1,8 @@
+declare module 'my-cjs-package/exports'
+declare module 'my-cjs-package/imports'
+declare module 'my-esm-package/exports'
+declare module 'my-esm-package/imports'
+declare module 'my-external-cjs-package/exports'
+declare module 'my-external-cjs-package/imports'
+declare module 'my-external-esm-package/exports'
+declare module 'my-external-esm-package/imports'
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/proxy.ts b/test/e2e/app-dir/next-condition/fixtures/proxy/proxy.ts
@@ -0,0 +1,15 @@
+import CJSExportsDefault from 'my-cjs-package/exports'
+import ExternalCJSExportsDefault from 'my-external-cjs-package/exports'
+import ESMExportsDefault from 'my-esm-package/exports'
+import ExternalESMExportsDefault from 'my-external-esm-package/exports'
+
+export default async function proxy(req: Request) {
+  if (!req.url.includes('/_next/')) {
+    console.log('==== MIDDLEWARE START ====')
+    console.log('CJSExportsDefault:', CJSExportsDefault)
+    console.log('ExternalCJSExportsDefault:', ExternalCJSExportsDefault)
+    console.log('ESMExportsDefault:', ESMExportsDefault)
+    console.log('ExternalESMExportsDefault:', ExternalESMExportsDefault)
+    console.log('==== MIDDLEWARE END ====')
+  }
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/proxy/sym-linked-packages b/test/e2e/app-dir/next-condition/fixtures/proxy/sym-linked-packages
@@ -0,0 +1 @@
+../../packages
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/.gitignore b/test/e2e/app-dir/next-condition/fixtures/render/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/...app-dir/next-condition/app/cjs/client.tsx → ...dition/fixtures/render/app/cjs/client.tsx b/...app-dir/next-condition/app/cjs/client.tsx → ...dition/fixtures/render/app/cjs/client.tsx
diff --git a/...e/app-dir/next-condition/app/cjs/page.tsx → ...ondition/fixtures/render/app/cjs/page.tsx b/...e/app-dir/next-condition/app/cjs/page.tsx → ...ondition/fixtures/render/app/cjs/page.tsx
diff --git a/...app-dir/next-condition/app/esm/client.tsx → ...dition/fixtures/render/app/esm/client.tsx b/...app-dir/next-condition/app/esm/client.tsx → ...dition/fixtures/render/app/esm/client.tsx
diff --git a/...e/app-dir/next-condition/app/esm/page.tsx → ...ondition/fixtures/render/app/esm/page.tsx b/...e/app-dir/next-condition/app/esm/page.tsx → ...ondition/fixtures/render/app/esm/page.tsx
diff --git a/...ext-condition/app/external-cjs/client.tsx → ...xtures/render/app/external-cjs/client.tsx b/...ext-condition/app/external-cjs/client.tsx → ...xtures/render/app/external-cjs/client.tsx
diff --git a/.../next-condition/app/external-cjs/page.tsx → ...fixtures/render/app/external-cjs/page.tsx b/.../next-condition/app/external-cjs/page.tsx → ...fixtures/render/app/external-cjs/page.tsx
diff --git a/...ext-condition/app/external-esm/client.tsx → ...xtures/render/app/external-esm/client.tsx b/...ext-condition/app/external-esm/client.tsx → ...xtures/render/app/external-esm/client.tsx
diff --git a/.../next-condition/app/external-esm/page.tsx → ...fixtures/render/app/external-esm/page.tsx b/.../next-condition/app/external-esm/page.tsx → ...fixtures/render/app/external-esm/page.tsx
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/app/layout.tsx b/test/e2e/app-dir/next-condition/fixtures/render/app/layout.tsx
@@ -0,0 +1,9 @@
+export default function Root({ children }: { children: React.ReactNode }) {
+  return (
+    <html>
+      <body>
+        <main>{children}</main>
+      </body>
+    </html>
+  )
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/next.config.js b/test/e2e/app-dir/next-condition/fixtures/render/next.config.js
@@ -0,0 +1,12 @@
+/**
+ * @type {import('next').NextConfig}
+ */
+
+const nextConfig = {
+  serverExternalPackages: [
+    'my-external-esm-package',
+    'my-external-cjs-package',
+  ],
+}
+
+module.exports = nextConfig
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/package.json b/test/e2e/app-dir/next-condition/fixtures/render/package.json
@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "my-cjs-package": "file:./sym-linked-packages/my-cjs-package",
+    "my-esm-package": "file:./sym-linked-packages/my-esm-package",
+    "my-external-cjs-package": "file:./sym-linked-packages/my-external-cjs-package",
+    "my-external-esm-package": "file:./sym-linked-packages/my-external-esm-package"
+  }
+}
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/packages.d.ts b/test/e2e/app-dir/next-condition/fixtures/render/packages.d.ts
@@ -0,0 +1,8 @@
+declare module 'my-cjs-package/exports'
+declare module 'my-cjs-package/imports'
+declare module 'my-esm-package/exports'
+declare module 'my-esm-package/imports'
+declare module 'my-external-cjs-package/exports'
+declare module 'my-external-cjs-package/imports'
+declare module 'my-external-esm-package/exports'
+declare module 'my-external-esm-package/imports'
diff --git a/test/e2e/app-dir/next-condition/fixtures/render/sym-linked-packages b/test/e2e/app-dir/next-condition/fixtures/render/sym-linked-packages
@@ -0,0 +1 @@
+../../packages