fix: trace nested server function factory re-export chain (#6166)

Author: schiller-manuel

e2e/react-start/server-functions/src/routes/factory/-functions/functions.ts

@@ -6,6 +6,8 @@ import { createFakeFn } from './createFakeFn'
 import { reexportFactory } from './reexportIndex'
 // Test star re-export syntax: `export * from './module'`
 import { starReexportFactory } from './starReexportIndex'
+// Test nested star re-export syntax: A -> B -> C chain
+import { nestedReexportFactory } from './nestedReexportA'
 
 export const fooFn = createFooServerFn().handler(({ context }) => {
   return {
@@ -115,3 +117,14 @@ export const starReexportedFactoryFn = starReexportFactory().handler(
     }
   },
 )
+
+// Test that nested star re-exported factories (A -> B -> C chain) work correctly
+// The middleware from nestedReexportFactory should execute and add { nested: 'nested-middleware-executed' } to context
+export const nestedReexportedFactoryFn = nestedReexportFactory().handler(
+  ({ context }) => {
+    return {
+      name: 'nestedReexportedFactoryFn',
+      context,
+    }
+  },
+)

e2e/react-start/server-functions/src/routes/factory/-functions/nestedReexportA.ts

@@ -0,0 +1,7 @@
+/**
+ * Top-level module in the nested re-export chain.
+ * Re-exports everything from nestedReexportB.
+ *
+ * Chain: nestedReexportA (this file) -> nestedReexportB -> nestedReexportC
+ */
+export * from './nestedReexportB'

e2e/react-start/server-functions/src/routes/factory/-functions/nestedReexportB.ts

@@ -0,0 +1,7 @@
+/**
+ * Middle module in the nested re-export chain.
+ * Re-exports everything from nestedReexportC.
+ *
+ * Chain: nestedReexportA -> nestedReexportB (this file) -> nestedReexportC
+ */
+export * from './nestedReexportC'

e2e/react-start/server-functions/src/routes/factory/-functions/nestedReexportC.ts

@@ -0,0 +1,20 @@
+/**
+ * This is the deepest module in the nested re-export chain.
+ * It defines a server function factory with middleware.
+ *
+ * Chain: nestedReexportA -> nestedReexportB -> nestedReexportC (this file)
+ */
+import { createMiddleware, createServerFn } from '@tanstack/react-start'
+
+const nestedMiddleware = createMiddleware({ type: 'function' }).server(
+  ({ next }) => {
+    console.log('nested middleware triggered')
+    return next({
+      context: { nested: 'nested-middleware-executed' } as const,
+    })
+  },
+)
+
+export const nestedReexportFactory = createServerFn({
+  method: 'GET',
+}).middleware([nestedMiddleware])

e2e/react-start/server-functions/src/routes/factory/index.tsx

@@ -12,6 +12,7 @@ import {
   fooFnPOST,
   localFn,
   localFnPOST,
+  nestedReexportedFactoryFn,
   reexportedFactoryFn,
   starReexportedFactoryFn,
 } from './-functions/functions'
@@ -152,6 +153,16 @@ const functions = {
       context: { starReexport: 'star-reexport-middleware-executed' },
     },
   },
+  // Test that nested star re-exported factories (A -> B -> C chain) work correctly
+  // The middleware from nestedReexportFactory should execute and add { nested: 'nested-middleware-executed' } to context
+  nestedReexportedFactoryFn: {
+    fn: nestedReexportedFactoryFn,
+    type: 'serverFn',
+    expected: {
+      name: 'nestedReexportedFactoryFn',
+      context: { nested: 'nested-middleware-executed' },
+    },
+  },
 } satisfies Record<string, TestCase>
 
 interface TestCase {

e2e/react-start/server-functions/tests/server-functions.spec.ts

@@ -591,3 +591,27 @@ test('star re-exported server function factory middleware executes correctly', a
     page.getByTestId('fn-comparison-starReexportedFactoryFn'),
   ).toContainText('equal')
 })
+
+test('nested star re-exported server function factory middleware executes correctly', async ({
+  page,
+}) => {
+  // This test specifically verifies that when a server function factory is re-exported
+  // through a nested chain (A -> B -> C) using `export * from './module'` syntax,
+  // the middleware still executes correctly.
+  await page.goto('/factory')
+
+  await expect(page.getByTestId('factory-route-component')).toBeInViewport()
+
+  // Click the button for the nested re-exported factory function
+  await page.getByTestId('btn-fn-nestedReexportedFactoryFn').click()
+
+  // Wait for the result
+  await expect(
+    page.getByTestId('fn-result-nestedReexportedFactoryFn'),
+  ).toContainText('nested-middleware-executed')
+
+  // Verify the full context was returned (middleware executed)
+  await expect(
+    page.getByTestId('fn-comparison-nestedReexportedFactoryFn'),
+  ).toContainText('equal')
+})