From a18110c0ec1ff42807659eec0841c7b62792f290 Mon Sep 17 00:00:00 2001
From: Jimmy Lai <laijimmy0@gmail.com>
Date: Sun, 16 Apr 2023 10:33:02 +0200
Subject: [PATCH 1/2] use private resolver for default page

---
 .../build/webpack/loaders/next-app-loader.ts  | 28 +++++++++++++------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/packages/next/src/build/webpack/loaders/next-app-loader.ts b/packages/next/src/build/webpack/loaders/next-app-loader.ts
index 85e0cc2c2a13a..01f275e5f92c5 100644
--- a/packages/next/src/build/webpack/loaders/next-app-loader.ts
+++ b/packages/next/src/build/webpack/loaders/next-app-loader.ts
@@ -51,7 +51,8 @@ const PAGE_SEGMENT = 'page$'
 
 type PathResolver = (
   pathname: string,
-  resolveDir?: boolean
+  resolveDir?: boolean,
+  internal?: boolean
 ) => Promise<string | undefined>
 
 export type ComponentsType = {
@@ -171,10 +172,7 @@ async function createTreeCodeFromPath(
     loaderContext,
     pageExtensions,
   }: {
-    resolver: (
-      pathname: string,
-      resolveDir?: boolean
-    ) => Promise<string | undefined>
+    resolver: PathResolver
     resolvePath: (pathname: string) => Promise<string>
     resolveParallelSegments: (
       pathname: string
@@ -365,7 +363,11 @@ async function createTreeCodeFromPath(
           (await resolver(
             `${appDirPrefix}${segmentPath}/${actualSegment}/default`
           )) ??
-          (await resolver(`next/dist/client/components/parallel-route-default`))
+          (await resolver(
+            `next/dist/client/components/parallel-route-default`,
+            false,
+            true
+          ))
 
         props[normalizeParallelKey(adjacentParallelSegment)] = `[
           '__DEFAULT__',
@@ -437,6 +439,13 @@ const nextAppLoader: AppLoader = async function nextAppLoader() {
 
   const resolve = this.getResolve(resolveOptions)
 
+  // a resolver for internal next files. We need to override the extensions, in case
+  // a project doesn't have the same ones as used by next.
+  const internalResolve = this.getResolve({
+    ...resolveOptions,
+    extensions: [...extensions, '.js', '.jsx', '.ts', '.tsx'],
+  })
+
   const normalizedAppPaths =
     typeof appPaths === 'string' ? [appPaths] : appPaths || []
 
@@ -471,13 +480,16 @@ const nextAppLoader: AppLoader = async function nextAppLoader() {
 
     return Object.entries(matched)
   }
-  const resolver: PathResolver = async (pathname, resolveDir) => {
+  const resolver: PathResolver = async (pathname, resolveDir, internal) => {
     if (resolveDir) {
       return createAbsolutePath(appDir, pathname)
     }
 
     try {
-      const resolved = await resolve(this.rootContext, pathname)
+      const resolved = await (internal ? internalResolve : resolve)(
+        this.rootContext,
+        pathname
+      )
       this.addDependency(resolved)
       return resolved
     } catch (err: any) {

From b21bd72b06694b9895573df68cf047ce629f7a75 Mon Sep 17 00:00:00 2001
From: Jimmy Lai <laijimmy0@gmail.com>
Date: Sun, 16 Apr 2023 10:44:47 +0200
Subject: [PATCH 2/2] add test

---
 test/e2e/app-dir/parallel-routes-not-found/next.config.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/e2e/app-dir/parallel-routes-not-found/next.config.js b/test/e2e/app-dir/parallel-routes-not-found/next.config.js
index bf49894afd400..358812ac96e49 100644
--- a/test/e2e/app-dir/parallel-routes-not-found/next.config.js
+++ b/test/e2e/app-dir/parallel-routes-not-found/next.config.js
@@ -2,6 +2,7 @@
  * @type {import('next').NextConfig}
  */
 const nextConfig = {
+  pageExtensions: ['tsx', 'ts'],
   experimental: { appDir: true },
 }