test(hono): Add E2E and unit tests for middleware tracing and route patterns

Add comprehensive test coverage for the Hono middleware instrumentation:

- E2E route-patterns tests for HTTP methods, registration styles, error capture
- E2E inline middleware tests for direct method, .all(), .on() with inline
  and separately registered middleware across all HTTP methods
- E2E negative test asserting .all() handlers don't create middleware spans
- Unit tests for responseHandler error capture and isAlreadyCaptured guard
- Unit tests for patchRoute arity heuristic (inline mw, separate mw, .on())
- Unit tests for sentry middleware without options (external init pattern)

Made-with: Cursor

Author: s1gr1d

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

@@ -8,7 +8,7 @@ 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'));
 
-// Self-contained sub-app registering its own middleware
+// Self-contained sub-app registering its own middleware via .use()
 const subAppWithMiddleware = new Hono();
 
 subAppWithMiddleware.use('/named/*', middlewareA);
@@ -19,12 +19,63 @@ subAppWithMiddleware.use('/anonymous/*', async (c, 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.
+// .all() handler (1 parameter) — should NOT be wrapped as middleware by patchRoute.
 subAppWithMiddleware.all('/all-handler', async function allCatchAll(c) {
   return c.json({ handler: 'all' });
 });
 
 subAppWithMiddleware.route('/', middlewareRoutes);
 
-export { middlewareRoutes, subAppWithMiddleware };
+// Sub-app with inline middleware for different registration styles.
+// patchRoute wraps non-last handlers per method+path group as middleware.
+const subAppWithInlineMiddleware = new Hono();
+
+const METHODS = ['get', 'post', 'put', 'delete', 'patch'] as const;
+
+// Direct method registration for each HTTP method
+METHODS.forEach(method => {
+  subAppWithInlineMiddleware[method](
+    '/direct',
+    async function inlineMiddleware(_c, next) {
+      await next();
+    },
+    c => c.text(`${method} direct response`),
+  );
+
+  subAppWithInlineMiddleware[method]('/direct/separately', async function inlineSeparateMiddleware(_c, next) {
+    await next();
+  });
+  subAppWithInlineMiddleware[method]('/direct/separately', c => c.text(`${method} direct separate response`));
+});
+
+// .all(): .all('/path', mw, handler)
+subAppWithInlineMiddleware.all(
+  '/all',
+  async function inlineMiddlewareAll(_c, next) {
+    await next();
+  },
+  c => c.text('all response'),
+);
+subAppWithInlineMiddleware.all('/all/separately', async function inlineSeparateMiddlewareAll(_c, next) {
+  await next();
+});
+subAppWithInlineMiddleware.all('/all/separately', c => c.text('all separate response'));
+
+// .on() registration for each HTTP method
+METHODS.forEach(method => {
+  subAppWithInlineMiddleware.on(
+    method,
+    '/on',
+    async function inlineMiddlewareOn(_c, next) {
+      await next();
+    },
+    c => c.text(`${method} on response`),
+  );
+
+  subAppWithInlineMiddleware.on(method, '/on/separately', async function inlineSeparateMiddlewareOn(_c, next) {
+    await next();
+  });
+  subAppWithInlineMiddleware.on(method, '/on/separately', c => c.text(`${method} on separate response`));
+});
+
+export { middlewareRoutes, subAppWithMiddleware, subAppWithInlineMiddleware };

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

@@ -0,0 +1,55 @@
+import { Hono } from 'hono';
+import { HTTPException } from 'hono/http-exception';
+
+const routePatterns = new Hono();
+
+const METHODS = ['get', 'post', 'put', 'delete', 'patch'] as const;
+
+// Direct method registration for each HTTP method (sync handlers)
+METHODS.forEach(method => {
+  routePatterns[method]('/', c => c.text(`${method} response`));
+});
+
+// Async handler
+routePatterns.get('/async', async c => {
+  await new Promise(resolve => setTimeout(resolve, 10));
+  return c.text('async response');
+});
+
+// .all() registration
+routePatterns.all('/all', c => c.text('all handler response'));
+
+// .on() registration
+METHODS.forEach(method => {
+  routePatterns.on(method, '/on', c => c.text(`${method} on response`));
+});
+
+// Error routes for direct method registration
+METHODS.forEach(method => {
+  routePatterns[method]('/500', () => {
+    throw new HTTPException(500, { message: 'response 500' });
+  });
+  routePatterns[method]('/401', () => {
+    throw new HTTPException(401, { message: 'response 401' });
+  });
+  routePatterns[method]('/402', () => {
+    throw new HTTPException(402, { message: 'response 402' });
+  });
+  routePatterns[method]('/403', () => {
+    throw new HTTPException(403, { message: 'response 403' });
+  });
+});
+
+// Error routes for .all()
+routePatterns.all('/all/500', () => {
+  throw new HTTPException(500, { message: 'response 500' });
+});
+
+// Error routes for .on()
+METHODS.forEach(method => {
+  routePatterns.on(method, '/on/500', () => {
+    throw new HTTPException(500, { message: 'response 500' });
+  });
+});
+
+export { routePatterns };

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

@@ -1,7 +1,8 @@
 import type { Hono } from 'hono';
 import { HTTPException } from 'hono/http-exception';
 import { failingMiddleware, middlewareA, middlewareB } from './middleware';
-import { middlewareRoutes, subAppWithMiddleware } from './route-groups/test-middleware';
+import { middlewareRoutes, subAppWithInlineMiddleware, subAppWithMiddleware } from './route-groups/test-middleware';
+import { routePatterns } from './route-groups/test-route-patterns';
 
 export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): void {
   app.get('/', c => {
@@ -36,4 +37,10 @@ export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): v
 
   // Sub-app middleware: registered on the sub-app, wrapped at mount time by route() patching
   app.route('/test-subapp-middleware', subAppWithMiddleware);
+
+  // Inline middleware patterns: direct method, .all(), .on() with inline/separate middleware
+  app.route('/test-inline-middleware', subAppWithInlineMiddleware);
+
+  // Route patterns: HTTP methods, .all(), .on(), sync/async, errors
+  app.route('/test-routes', routePatterns);
 }

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

@@ -97,10 +97,7 @@ for (const { name, prefix } of SCENARIOS) {
 
     test('captures error thrown in middleware', async ({ baseURL }) => {
       const errorPromise = waitForError(APP_NAME, event => {
-        return (
-          event.exception?.values?.[0]?.value === 'Middleware error' &&
-          event.exception?.values?.[0]?.mechanism?.type === 'auto.middleware.hono'
-        );
+        return event.exception?.values?.[0]?.value === 'Middleware error';
       });
 
       const response = await fetch(`${baseURL}${prefix}/error`);
@@ -152,8 +149,8 @@ for (const { name, prefix } of SCENARIOS) {
   });
 }
 
-test.describe('patchRoute wraps .all() as middleware span (in sub-app)', () => {
-  test('patchRoute wraps .all() as middleware span', async ({ baseURL }) => {
+test.describe('.all() handler in sub-app', () => {
+  test('does not create middleware span for .all() route handler', async ({ baseURL }) => {
     const transactionPromise = waitForTransaction(APP_NAME, event => {
       return (
         event.contexts?.trace?.op === 'http.server' && event.transaction === 'GET /test-subapp-middleware/all-handler'
@@ -169,20 +166,57 @@ test.describe('patchRoute wraps .all() as middleware span (in sub-app)', () => {
     const transaction = await transactionPromise;
     const spans = transaction.spans || [];
 
-    // On Bun/Cloudflare, patchRoute is the sole wrapper and sees the original
-    // function name. It wraps .all() handlers identically to .use() middleware
-    // because both produce method:'ALL' in Hono's route record.
     const allHandlerSpan = spans.find(
       (span: SpanJSON) => span.op === 'middleware.hono' && span.description === 'allCatchAll',
     );
-
-    expect(allHandlerSpan).toEqual(
-      expect.objectContaining({
-        description: 'allCatchAll',
-        op: 'middleware.hono',
-        origin: 'auto.middleware.hono',
-        status: 'ok',
-      }),
-    );
+    expect(allHandlerSpan).toBeUndefined();
   });
 });
+
+const INLINE_PREFIX = '/test-inline-middleware';
+
+const REGISTRATION_STYLES = [
+  { name: 'direct method (.get())', path: '/direct' },
+  { name: '.all()', path: '/all' },
+  { name: '.on()', path: '/on' },
+] as const;
+
+const MIDDLEWARE_STYLES = [
+  { name: 'inline', path: '' },
+  { name: 'separately registered', path: '/separately' },
+] as const;
+
+test.describe('inline middleware spans (sub-app)', () => {
+  for (const { name: regName, path: regPath } of REGISTRATION_STYLES) {
+    for (const { name: mwName, path: mwPath } of MIDDLEWARE_STYLES) {
+      test(`creates middleware span for ${mwName} middleware via ${regName}`, async ({ baseURL }) => {
+        const fullPath = `${INLINE_PREFIX}${regPath}${mwPath}`;
+
+        const transactionPromise = waitForTransaction(APP_NAME, event => {
+          return event.contexts?.trace?.op === 'http.server' && event.transaction === `GET ${fullPath}`;
+        });
+
+        const response = await fetch(`${baseURL}${fullPath}`);
+        expect(response.status).toBe(200);
+
+        const transaction = await transactionPromise;
+
+        const EXPECTED_DESCRIPTIONS: Record<string, Record<string, string>> = {
+          '/direct': { '': 'inlineMiddleware', '/separately': 'inlineSeparateMiddleware' },
+          '/all': { '': 'inlineMiddlewareAll', '/separately': 'inlineSeparateMiddlewareAll' },
+          '/on': { '': 'inlineMiddlewareOn', '/separately': 'inlineSeparateMiddlewareOn' },
+        };
+        const expectedDescription = EXPECTED_DESCRIPTIONS[regPath]![mwPath]!;
+
+        expect(transaction.spans).toContainEqual(
+          expect.objectContaining({
+            description: expectedDescription,
+            op: 'middleware.hono',
+            origin: 'auto.middleware.hono',
+            status: 'ok',
+          }),
+        );
+      });
+    }
+  }
+});

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

@@ -0,0 +1,144 @@
+import { expect, test } from '@playwright/test';
+import { waitForError, waitForTransaction } from '@sentry-internal/test-utils';
+import { APP_NAME } from './constants';
+
+const PREFIX = '/test-routes';
+
+const REGISTRATION_STYLES = [
+  { name: 'direct method', path: '' },
+  { name: '.all()', path: '/all' },
+  { name: '.on()', path: '/on' },
+] as const;
+
+test.describe('HTTP methods', () => {
+  for (const method of ['POST', 'PUT', 'DELETE', 'PATCH']) {
+    test(`sends transaction for ${method}`, async ({ baseURL }) => {
+      const transactionPromise = waitForTransaction(APP_NAME, event => {
+        return event.contexts?.trace?.op === 'http.server' && event.transaction === `${method} ${PREFIX}`;
+      });
+
+      const response = await fetch(`${baseURL}${PREFIX}`, { method });
+      expect(response.status).toBe(200);
+
+      const transaction = await transactionPromise;
+      expect(transaction.contexts?.trace?.op).toBe('http.server');
+      expect(transaction.transaction).toBe(`${method} ${PREFIX}`);
+    });
+  }
+});
+
+test.describe('route registration styles', () => {
+  for (const { name, path } of REGISTRATION_STYLES) {
+    test(`${name} sends transaction`, async ({ baseURL }) => {
+      const transactionPromise = waitForTransaction(APP_NAME, event => {
+        return event.contexts?.trace?.op === 'http.server' && event.transaction === `GET ${PREFIX}${path}`;
+      });
+
+      const response = await fetch(`${baseURL}${PREFIX}${path}`);
+      expect(response.status).toBe(200);
+
+      const transaction = await transactionPromise;
+      expect(transaction.contexts?.trace?.op).toBe('http.server');
+      expect(transaction.transaction).toBe(`GET ${PREFIX}${path}`);
+    });
+  }
+
+  for (const { name, path } of [
+    { name: '.all()', path: '/all' },
+    { name: '.on()', path: '/on' },
+  ]) {
+    test(`${name} responds to POST`, async ({ baseURL }) => {
+      const transactionPromise = waitForTransaction(APP_NAME, event => {
+        return event.contexts?.trace?.op === 'http.server' && event.transaction === `POST ${PREFIX}${path}`;
+      });
+
+      const response = await fetch(`${baseURL}${PREFIX}${path}`, { method: 'POST' });
+      expect(response.status).toBe(200);
+
+      const transaction = await transactionPromise;
+      expect(transaction.transaction).toBe(`POST ${PREFIX}${path}`);
+    });
+  }
+});
+
+test('async handler sends transaction', async ({ baseURL }) => {
+  const transactionPromise = waitForTransaction(APP_NAME, event => {
+    return event.contexts?.trace?.op === 'http.server' && event.transaction === `GET ${PREFIX}/async`;
+  });
+
+  const response = await fetch(`${baseURL}${PREFIX}/async`);
+  expect(response.status).toBe(200);
+
+  const transaction = await transactionPromise;
+  expect(transaction.contexts?.trace?.op).toBe('http.server');
+});
+
+test.describe('500 HTTPException capture', () => {
+  for (const { name, path } of REGISTRATION_STYLES) {
+    test(`captures 500 from ${name} route with correct mechanism`, async ({ baseURL }) => {
+      const fullPath = `${PREFIX}${path}/500`;
+
+      const errorPromise = waitForError(APP_NAME, event => {
+        return event.exception?.values?.[0]?.value === 'response 500' && !!event.request?.url?.includes(fullPath);
+      });
+
+      const response = await fetch(`${baseURL}${fullPath}`);
+      expect(response.status).toBe(500);
+
+      const errorEvent = await errorPromise;
+      expect(errorEvent.exception?.values?.[0]?.value).toBe('response 500');
+      expect(errorEvent.exception?.values?.[0]?.mechanism).toEqual(
+        expect.objectContaining({
+          handled: false,
+          type: 'auto.http.hono.context_error',
+        }),
+      );
+    });
+  }
+
+  test('captures 500 error with POST method', async ({ baseURL }) => {
+    const errorPromise = waitForError(APP_NAME, event => {
+      return (
+        event.exception?.values?.[0]?.value === 'response 500' &&
+        !!event.request?.url?.includes(`${PREFIX}/500`) &&
+        event.request?.method === 'POST'
+      );
+    });
+
+    const response = await fetch(`${baseURL}${PREFIX}/500`, { method: 'POST' });
+    expect(response.status).toBe(500);
+
+    const errorEvent = await errorPromise;
+    expect(errorEvent.exception?.values?.[0]?.value).toBe('response 500');
+    expect(errorEvent.exception?.values?.[0]?.mechanism).toEqual(
+      expect.objectContaining({
+        handled: false,
+        type: 'auto.http.hono.context_error',
+      }),
+    );
+  });
+});
+
+test.describe('4xx HTTPException capture', () => {
+  for (const code of [401, 402, 403]) {
+    test(`captures ${code} HTTPException`, async ({ baseURL }) => {
+      const fullPath = `${PREFIX}/${code}`;
+
+      const errorPromise = waitForError(APP_NAME, event => {
+        return event.exception?.values?.[0]?.value === `response ${code}` && !!event.request?.url?.includes(fullPath);
+      });
+
+      const response = await fetch(`${baseURL}${fullPath}`);
+      expect(response.status).toBe(code);
+
+      const errorEvent = await errorPromise;
+      expect(errorEvent.exception?.values?.[0]?.value).toBe(`response ${code}`);
+      expect(errorEvent.exception?.values?.[0]?.mechanism).toEqual(
+        expect.objectContaining({
+          handled: false,
+          type: 'auto.http.hono.context_error',
+        }),
+      );
+    });
+  }
+});