test(hono): Add E2E tests for middleware spans (#20465)

Patches `app.route` to also support middleware defined in Hono route
groups.

The Node instrumentation still produces too many spans, this will be
fixed in another PR - one test is skipped for now.

Closes #20449

Author: s1gr1d

dev-packages/e2e-tests/test-applications/hono-4/playwright.config.ts

@@ -1,8 +1,5 @@
 import { getPlaywrightConfig } from '@sentry-internal/test-utils';
-
-type Runtime = 'cloudflare' | 'node' | 'bun';
-
-const RUNTIME = (process.env.RUNTIME || 'cloudflare') as Runtime;
+import { RUNTIME, type Runtime } from './tests/constants';
 
 const testEnv = process.env.TEST_ENV;
 

dev-packages/e2e-tests/test-applications/hono-4/src/route-groups/test-middleware.ts

@@ -1,10 +1,30 @@
 import { Hono } from 'hono';
+import { failingMiddleware, middlewareA, middlewareB } from '../middleware';
 
-const testMiddleware = new Hono();
+const middlewareRoutes = new Hono();
 
-testMiddleware.get('/named', c => c.json({ middleware: 'named' }));
-testMiddleware.get('/anonymous', c => c.json({ middleware: 'anonymous' }));
-testMiddleware.get('/multi', c => c.json({ middleware: 'multi' }));
-testMiddleware.get('/error', c => c.text('should not reach'));
+middlewareRoutes.get('/named', c => c.json({ middleware: 'named' }));
+middlewareRoutes.get('/anonymous', c => c.json({ middleware: 'anonymous' }));
+middlewareRoutes.get('/multi', c => c.json({ middleware: 'multi' }));
+middlewareRoutes.get('/error', c => c.text('should not reach'));
 
-export { testMiddleware };
+// Self-contained sub-app registering its own middleware
+const subAppWithMiddleware = new Hono();
+
+subAppWithMiddleware.use('/named/*', middlewareA);
+subAppWithMiddleware.use('/anonymous/*', async (c, next) => {
+  c.header('X-Custom', 'anonymous');
+  await next();
+});
+subAppWithMiddleware.use('/multi/*', middlewareA, middlewareB);
+subAppWithMiddleware.use('/error/*', failingMiddleware);
+
+// .all() produces the same method:'ALL' as .use() in Hono's route record.
+// Wrapping it is harmless (onlyIfParent:true) — this route exists to prove that.
+subAppWithMiddleware.all('/all-handler', async function allCatchAll(c) {
+  return c.json({ handler: 'all' });
+});
+
+subAppWithMiddleware.route('/', middlewareRoutes);
+
+export { middlewareRoutes, subAppWithMiddleware };

dev-packages/e2e-tests/test-applications/hono-4/src/routes.ts

@@ -1,7 +1,7 @@
 import type { Hono } from 'hono';
 import { HTTPException } from 'hono/http-exception';
-import { testMiddleware } from './route-groups/test-middleware';
-import { middlewareA, middlewareB, failingMiddleware } from './middleware';
+import { failingMiddleware, middlewareA, middlewareB } from './middleware';
+import { middlewareRoutes, subAppWithMiddleware } from './route-groups/test-middleware';
 
 export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): void {
   app.get('/', c => {
@@ -24,16 +24,16 @@ export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): v
     throw new HTTPException(code, { message: `HTTPException ${code}` });
   });
 
-  // === Middleware ===
-  // Middleware is registered on the main app (the patched instance) via `app.use()`
-  // TODO: In the future, we may want to support middleware registration on sub-apps (route groups)
+  // Root-app middleware: registered on the patched main app instance
   app.use('/test-middleware/named/*', middlewareA);
   app.use('/test-middleware/anonymous/*', async (c, next) => {
     c.header('X-Custom', 'anonymous');
     await next();
   });
   app.use('/test-middleware/multi/*', middlewareA, middlewareB);
   app.use('/test-middleware/error/*', failingMiddleware);
+  app.route('/test-middleware', middlewareRoutes);
 
-  app.route('/test-middleware', testMiddleware);
+  // Sub-app middleware: registered on the sub-app, wrapped at mount time by route() patching
+  app.route('/test-subapp-middleware', subAppWithMiddleware);
 }

dev-packages/e2e-tests/test-applications/hono-4/tests/constants.ts

@@ -0,0 +1,6 @@
+export type Runtime = 'cloudflare' | 'node' | 'bun';
+
+export const RUNTIME = (process.env.RUNTIME || 'cloudflare') as Runtime;
+export const isNode = RUNTIME === 'node';
+
+export const APP_NAME = 'hono-4';

dev-packages/e2e-tests/test-applications/hono-4/tests/errors.test.ts

@@ -1,7 +1,6 @@
 import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
-
-const APP_NAME = 'hono-4';
+import { APP_NAME } from './constants';
 
 test('captures error thrown in route handler', async ({ baseURL }) => {
   const errorWaiter = waitForError(APP_NAME, event => {