Add test for serverExternalPackages inside node_modules (#68156)

Adds a test for the change in #67948

Author: mischnic

test/e2e/app-dir/app-external/app-external.test.ts

@@ -229,6 +229,11 @@ describe('app dir - external dependency', () => {
       const $ = await next.render$('/esm/react-namespace-import')
       expect($('#namespace-import-esm').text()).toBe('namespace-import:esm')
     })
+
+    it('should apply serverExternalPackages inside of node_modules', async () => {
+      const html = await next.render('/transitive-external')
+      expect(html).toContain('transitive loaded a')
+    })
   })
 
   describe('mixed syntax external modules', () => {

test/e2e/app-dir/app-external/app/transitive-external/page.js

@@ -0,0 +1,6 @@
+import { load } from 'transitive'
+
+export default async function Page() {
+  let value = await load('a')
+  return <d1iv>{value}</d1iv>
+}

test/e2e/app-dir/app-external/next.config.js

@@ -1,5 +1,9 @@
 module.exports = {
   reactStrictMode: true,
   transpilePackages: ['css', 'font', 'transpile-ts-lib', 'transpile-cjs-lib'],
-  serverExternalPackages: ['conditional-exports-optout', 'dual-pkg-optout'],
+  serverExternalPackages: [
+    'conditional-exports-optout',
+    'dual-pkg-optout',
+    'transitive-external',
+  ],
 }