Handle 404 responses in RSC server function wrapper

Author: onurtemizkan

packages/react-router/src/server/rsc/wrapServerFunction.ts

@@ -10,7 +10,13 @@ import {
   SPAN_STATUS_OK,
   startSpan,
 } from '@sentry/core';
-import { isErrorCaptured, isRedirectResponse, markErrorAsCaptured, safeFlushServerless } from './responseUtils';
+import {
+  isErrorCaptured,
+  isNotFoundResponse,
+  isRedirectResponse,
+  markErrorAsCaptured,
+  safeFlushServerless,
+} from './responseUtils';
 import type { WrapServerFunctionOptions } from './types';
 
 /**
@@ -73,11 +79,16 @@ export function wrapServerFunction<T extends (...args: any[]) => Promise<any>>(
         } catch (error) {
           // Check if the error is a redirect (common pattern in server functions)
           if (isRedirectResponse(error)) {
-            // Don't capture redirects as errors, but still end the span
             span.setStatus({ code: SPAN_STATUS_OK });
             throw error;
           }
 
+          // Check if the error is a not-found response (404)
+          if (isNotFoundResponse(error)) {
+            span.setStatus({ code: SPAN_STATUS_ERROR, message: 'not_found' });
+            throw error;
+          }
+
           span.setStatus({ code: SPAN_STATUS_ERROR, message: 'internal_error' });
 
           // Only capture if not already captured (error may bubble through nested server functions or components)

packages/react-router/test/server/rsc/wrapServerFunction.test.ts

@@ -138,6 +138,22 @@ describe('wrapServerFunction', () => {
     expect(core.captureException).not.toHaveBeenCalled();
   });
 
+  it('should not capture not-found errors as exceptions', async () => {
+    const notFoundResponse = new Response(null, { status: 404 });
+    const mockServerFn = vi.fn().mockRejectedValue(notFoundResponse);
+    const mockSetStatus = vi.fn();
+    const mockSetTransactionName = vi.fn();
+
+    (core.getIsolationScope as any).mockReturnValue({ setTransactionName: mockSetTransactionName });
+    (core.startSpan as any).mockImplementation((_: any, fn: any) => fn({ setStatus: mockSetStatus }));
+
+    const wrappedFn = wrapServerFunction('testFunction', mockServerFn);
+
+    await expect(wrappedFn()).rejects.toBe(notFoundResponse);
+    expect(mockSetStatus).toHaveBeenCalledWith({ code: 2, message: 'not_found' });
+    expect(core.captureException).not.toHaveBeenCalled();
+  });
+
   it('should preserve function name', () => {
     const mockServerFn = vi.fn().mockResolvedValue('result');
     const wrappedFn = wrapServerFunction('testFunction', mockServerFn);