feat(nextjs): Automatically skip middleware requests for tunnel route

packages/nextjs/src/common/wrapMiddlewareWithSentry.ts

@@ -27,6 +27,31 @@ export function wrapMiddlewareWithSentry<H extends EdgeRouteHandler>(
 ): (...params: Parameters<H>) => Promise<ReturnType<H>> {
   return new Proxy(middleware, {
     apply: async (wrappingTarget, thisArg, args: Parameters<H>) => {
+      const tunnelRoute =
+        '_sentryRewritesTunnelPath' in globalThis
+          ? (globalThis as Record<string, unknown>)._sentryRewritesTunnelPath
+          : undefined;
+
+      if (tunnelRoute && typeof tunnelRoute === 'string') {
+        const req: unknown = args[0];
+        // Check if the current request matches the tunnel route
+        if (req instanceof Request) {
+          const url = new URL(req.url);
+          const isTunnelRequest = url.pathname.startsWith(tunnelRoute);
+
+          if (isTunnelRequest) {
+            // Create a simple response that mimics NextResponse.next() so we don't need to import internals here
+            // which breaks next 13 apps
+            // https://github.com/vercel/next.js/blob/c12c9c1f78ad384270902f0890dc4cd341408105/packages/next/src/server/web/spec-extension/response.ts#L146
+            return new Response(null, {
+              status: 200,
+              headers: {
+                'x-middleware-next': '1',
+              },
+            }) as ReturnType<H>;
+          }
+        }
+      }
       // TODO: We still should add central isolation scope creation for when our build-time instrumentation does not work anymore with turbopack.
       return withIsolationScope(isolationScope => {
         const req: unknown = args[0];

packages/nextjs/src/config/withSentryConfig.ts

@@ -107,17 +107,17 @@ function getFinalConfigObject(
         showedExportModeTunnelWarning = true;
         // eslint-disable-next-line no-console
         console.warn(
-          '[@sentry/nextjs] The Sentry Next.js SDK `tunnelRoute` option will not work in combination with Next.js static exports. The `tunnelRoute` option uses serverside features that cannot be accessed in export mode. If you still want to tunnel Sentry events, set up your own tunnel: https://docs.sentry.io/platforms/javascript/troubleshooting/#using-the-tunnel-option',
+          '[@sentry/nextjs] The Sentry Next.js SDK `tunnelRoute` option will not work in combination with Next.js static exports. The `tunnelRoute` option uses server-side features that cannot be accessed in export mode. If you still want to tunnel Sentry events, set up your own tunnel: https://docs.sentry.io/platforms/javascript/troubleshooting/#using-the-tunnel-option',
         );
       }
     } else {
       const resolvedTunnelRoute =
-        typeof userSentryOptions.tunnelRoute === 'boolean'
+        typeof userSentryOptions.tunnelRoute === 'boolean' && userSentryOptions.tunnelRoute === true
           ? generateRandomTunnelRoute()
           : userSentryOptions.tunnelRoute;
 
       // Update the global options object to use the resolved value everywhere
-      userSentryOptions.tunnelRoute = resolvedTunnelRoute;
+      userSentryOptions.tunnelRoute = resolvedTunnelRoute || undefined;
       setUpTunnelRewriteRules(incomingUserNextConfigObject, resolvedTunnelRoute);
     }
   }

packages/nextjs/test/config/wrappers.test.ts

@@ -2,7 +2,12 @@ import type { Client } from '@sentry/core';
 import * as SentryCore from '@sentry/core';
 import type { IncomingMessage, ServerResponse } from 'http';
 import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
-import { wrapGetInitialPropsWithSentry, wrapGetServerSidePropsWithSentry } from '../../src/common';
+import {
+  wrapGetInitialPropsWithSentry,
+  wrapGetServerSidePropsWithSentry,
+  wrapMiddlewareWithSentry,
+} from '../../src/common';
+import type { EdgeRouteHandler } from '../../src/edge/types';
 
 const startSpanManualSpy = vi.spyOn(SentryCore, 'startSpanManual');
 
@@ -84,3 +89,102 @@ describe('data-fetching function wrappers should not create manual spans', () =>
     expect(mockSetAttribute).not.toHaveBeenCalled();
   });
 });
+
+describe('wrapMiddlewareWithSentry', () => {
+  afterEach(() => {
+    vi.clearAllMocks();
+    if ('_sentryRewritesTunnelPath' in globalThis) {
+      delete (globalThis as any)._sentryRewritesTunnelPath;
+    }
+  });
+
+  test('should skip processing and return NextResponse.next() for tunnel route requests', async () => {
+    // Set up tunnel route in global
+    (globalThis as any)._sentryRewritesTunnelPath = '/monitoring/tunnel';
+
+    const origFunction: EdgeRouteHandler = vi.fn(async () => ({ status: 200 }));
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    // Create a mock Request that matches the tunnel route
+    const mockRequest = new Request('https://example.com/monitoring/tunnel?o=123');
+
+    const result = await wrappedOriginal(mockRequest);
+
+    // Should skip calling the original function
+    expect(origFunction).not.toHaveBeenCalled();
+    expect(result).toBeDefined();
+  });
+
+  test('should process normal request and call original function', async () => {
+    const mockReturnValue = { status: 200 };
+    const origFunction: EdgeRouteHandler = vi.fn(async (..._args) => mockReturnValue);
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    const mockRequest = new Request('https://example.com/api/users', { method: 'GET' });
+
+    const result = await wrappedOriginal(mockRequest);
+
+    expect(origFunction).toHaveBeenCalledWith(mockRequest);
+    expect(result).toBe(mockReturnValue);
+  });
+
+  test('should handle non-Request arguments', async () => {
+    const mockReturnValue = { status: 200 };
+    const origFunction: EdgeRouteHandler = vi.fn(async (..._args) => mockReturnValue);
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    const mockArgs = { someProperty: 'value' };
+
+    const result = await wrappedOriginal(mockArgs);
+
+    expect(origFunction).toHaveBeenCalledWith(mockArgs);
+    expect(result).toBe(mockReturnValue);
+  });
+
+  test('should handle errors in middleware function', async () => {
+    const testError = new Error('Test middleware error');
+    const origFunction: EdgeRouteHandler = vi.fn(async (..._args) => {
+      throw testError;
+    });
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    const mockRequest = new Request('https://example.com/api/users');
+
+    await expect(wrappedOriginal(mockRequest)).rejects.toThrow('Test middleware error');
+    expect(origFunction).toHaveBeenCalledWith(mockRequest);
+  });
+
+  test('should not process tunnel route when no tunnel path is set', async () => {
+    if ('_sentryRewritesTunnelPath' in globalThis) {
+      delete (globalThis as any)._sentryRewritesTunnelPath;
+    }
+
+    const mockReturnValue = { status: 200 };
+    const origFunction: EdgeRouteHandler = vi.fn(async (..._args) => mockReturnValue);
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    const mockRequest = new Request('https://example.com/monitoring/tunnel/sentry?o=123');
+
+    const result = await wrappedOriginal(mockRequest);
+
+    // Should process normally since no tunnel path is configured
+    expect(origFunction).toHaveBeenCalledWith(mockRequest);
+    expect(result).toBe(mockReturnValue);
+  });
+
+  test('should process request when tunnel path is set but request does not match', async () => {
+    (globalThis as any)._sentryRewritesTunnelPath = '/monitoring/tunnel';
+
+    const mockReturnValue = { status: 200 };
+    const origFunction: EdgeRouteHandler = vi.fn(async (..._args) => mockReturnValue);
+    const wrappedOriginal = wrapMiddlewareWithSentry(origFunction);
+
+    const mockRequest = new Request('https://example.com/api/users', { method: 'GET' });
+
+    const result = await wrappedOriginal(mockRequest);
+
+    // Should process normally since request doesn't match tunnel path
+    expect(origFunction).toHaveBeenCalledWith(mockRequest);
+    expect(result).toBe(mockReturnValue);
+  });
+});