From dba9383b91aaaa4cad2659748ba203ba013512a2 Mon Sep 17 00:00:00 2001
From: Jiachi Liu <inbox@huozhi.im>
Date: Wed, 23 Oct 2024 23:59:44 +0200
Subject: [PATCH] fix undefined default export error msg

---
 .../src/server/app-render/create-component-tree.tsx |  3 ++-
 .../acceptance-app/undefined-default-export.test.ts | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/packages/next/src/server/app-render/create-component-tree.tsx b/packages/next/src/server/app-render/create-component-tree.tsx
index d355c052a0a36..a388b7e20ec1b 100644
--- a/packages/next/src/server/app-render/create-component-tree.tsx
+++ b/packages/next/src/server/app-render/create-component-tree.tsx
@@ -53,8 +53,9 @@ function errorMissingDefaultExport(
   pagePath: string,
   convention: string
 ): never {
+  const normalizedPagePath = pagePath === '/' ? '' : pagePath
   throw new Error(
-    `The default export is not a React Component in "${pagePath}/${convention}"`
+    `The default export is not a React Component in "${normalizedPagePath}/${convention}"`
   )
 }
 
diff --git a/test/development/acceptance-app/undefined-default-export.test.ts b/test/development/acceptance-app/undefined-default-export.test.ts
index 9cc391a5cf719..c71dcd3d30c24 100644
--- a/test/development/acceptance-app/undefined-default-export.test.ts
+++ b/test/development/acceptance-app/undefined-default-export.test.ts
@@ -49,6 +49,19 @@ describe('Undefined default export', () => {
   })
 
   it('should error when page component export is not valid', async () => {
+    const { session, cleanup } = await sandbox(next, undefined, '/')
+
+    await next.patchFile('app/page.js', 'const a = 123')
+
+    await session.assertHasRedbox()
+    expect(await session.getRedboxDescription()).toInclude(
+      'The default export is not a React Component in "/page"'
+    )
+
+    await cleanup()
+  })
+
+  it('should error when root page component export is not valid', async () => {
     const { session, cleanup } = await sandbox(
       next,
       undefined,