test(cloudflare): Enable multi-worker tests for CF integration tests (#19938)

This adds tests for multi worker in integration tests by adding a
`wrangler-sub-worker.jsonc` into it. Everything else is then according
the official [Service Binding
docs](https://developers.cloudflare.com/workers/runtime-apis/bindings/service-bindings/).

So in the `worker-service-bindings` folder there is now a test which
connects "Worker A" with "Worker B". This is enabled by having "Worker
B" running as `wrangler-sub-worker.jsonc` and "Worker A" is referencing
to "Worker B" inside the normal "wrangler.jsonc". Inside "Worker A" you
can then use `env.ANOTHER_WORKER` to have an RPC between two workers.

This will be important for the tests for #16898

Author: JPeer264

dev-packages/cloudflare-integration-tests/runner.ts

@@ -105,6 +105,7 @@ export function createRunner(...paths: string[]) {
       let envelopeCount = 0;
       const { resolve: setWorkerPort, promise: workerPortPromise } = deferredPromise<number>();
       let child: ReturnType<typeof spawn> | undefined;
+      let childSubWorker: ReturnType<typeof spawn> | undefined;
 
       /** Called after each expect callback to check if we're complete */
       function expectCallbackCalled(): void {
@@ -168,7 +169,7 @@ export function createRunner(...paths: string[]) {
       }
 
       createBasicSentryServer(newEnvelope)
-        .then(([mockServerPort, mockServerClose]) => {
+        .then(async ([mockServerPort, mockServerClose]) => {
           if (mockServerClose) {
             CLEANUP_STEPS.add(() => {
               mockServerClose();
@@ -181,6 +182,49 @@ export function createRunner(...paths: string[]) {
             ? ['inherit', 'inherit', 'inherit', 'ipc']
             : ['ignore', 'ignore', 'ignore', 'ipc'];
 
+          const onChildError = (e: Error) => {
+            // eslint-disable-next-line no-console
+            console.error('Error starting child process:', e);
+            reject(e);
+          };
+
+          function onChildMessage(message: string, onReady?: (port: number) => void): void {
+            const msg = JSON.parse(message) as { event: string; port?: number };
+            if (msg.event === 'DEV_SERVER_READY' && typeof msg.port === 'number') {
+              if (process.env.DEBUG) log('worker ready on port', msg.port);
+              onReady?.(msg.port);
+            }
+          }
+
+          if (existsSync(join(testPath, 'wrangler-sub-worker.jsonc'))) {
+            childSubWorker = spawn(
+              'wrangler',
+              [
+                'dev',
+                '--config',
+                join(testPath, 'wrangler-sub-worker.jsonc'),
+                '--show-interactive-dev-session',
+                'false',
+                '--var',
+                `SENTRY_DSN:http://public@localhost:${mockServerPort}/1337`,
+                '--port',
+                '0',
+                '--inspector-port',
+                '0',
+              ],
+              { stdio, signal },
+            );
+
+            // Wait for the sub-worker to be ready before starting the main worker
+            await new Promise<void>((resolveSubWorker, rejectSubWorker) => {
+              childSubWorker!.on('message', (msg: string) => onChildMessage(msg, () => resolveSubWorker()));
+              childSubWorker!.on('error', rejectSubWorker);
+              childSubWorker!.on('exit', code => {
+                rejectSubWorker(new Error(`Sub-worker exited with code ${code}`));
+              });
+            });
+          }
+
           child = spawn(
             'wrangler',
             [
@@ -199,21 +243,12 @@ export function createRunner(...paths: string[]) {
 
           CLEANUP_STEPS.add(() => {
             child?.kill();
+            childSubWorker?.kill();
           });
 
-          child.on('error', e => {
-            // eslint-disable-next-line no-console
-            console.error('Error starting child process:', e);
-            reject(e);
-          });
-
-          child.on('message', (message: string) => {
-            const msg = JSON.parse(message) as { event: string; port?: number };
-            if (msg.event === 'DEV_SERVER_READY' && typeof msg.port === 'number') {
-              setWorkerPort(msg.port);
-              if (process.env.DEBUG) log('worker ready on port', msg.port);
-            }
-          });
+          childSubWorker?.on('error', onChildError);
+          child.on('error', onChildError);
+          child.on('message', (msg: string) => onChildMessage(msg, setWorkerPort));
         })
         .catch(e => reject(e));
 

dev-packages/cloudflare-integration-tests/suites/tracing/worker-service-binding/index-sub-worker.ts

@@ -0,0 +1,19 @@
+import * as Sentry from '@sentry/cloudflare';
+
+interface Env {
+  SENTRY_DSN: string;
+}
+
+const myWorker = {
+  async fetch(request: Request) {
+    return new Response('Hello from another worker!');
+  },
+};
+
+export default Sentry.withSentry(
+  (env: Env) => ({
+    dsn: env.SENTRY_DSN,
+    tracesSampleRate: 1.0,
+  }),
+  myWorker,
+);

dev-packages/cloudflare-integration-tests/suites/tracing/worker-service-binding/index.ts

@@ -0,0 +1,20 @@
+import * as Sentry from '@sentry/cloudflare';
+
+interface Env {
+  SENTRY_DSN: string;
+  ANOTHER_WORKER: Fetcher;
+}
+
+export default Sentry.withSentry(
+  (env: Env) => ({
+    dsn: env.SENTRY_DSN,
+    tracesSampleRate: 1.0,
+  }),
+  {
+    async fetch(request, env) {
+      const response = await env.ANOTHER_WORKER.fetch(new Request('http://fake-host/hello'));
+      const text = await response.text();
+      return new Response(text);
+    },
+  } satisfies ExportedHandler<Env>,
+);

dev-packages/cloudflare-integration-tests/suites/tracing/worker-service-binding/test.ts

@@ -0,0 +1,45 @@
+import { expect, it } from 'vitest';
+import type { Event } from '@sentry/core';
+import { createRunner } from '../../../runner';
+
+it('adds a trace to a worker via service binding', async ({ signal }) => {
+  const runner = createRunner(__dirname)
+    .expect(envelope => {
+      const transactionEvent = envelope[1]?.[0]?.[1] as Event;
+      expect(transactionEvent).toEqual(
+        expect.objectContaining({
+          contexts: expect.objectContaining({
+            trace: expect.objectContaining({
+              op: 'http.server',
+              data: expect.objectContaining({
+                'sentry.origin': 'auto.http.cloudflare',
+              }),
+              origin: 'auto.http.cloudflare',
+            }),
+          }),
+          transaction: 'GET /',
+        }),
+      );
+    })
+    .expect(envelope => {
+      const transactionEvent = envelope[1]?.[0]?.[1] as Event;
+      expect(transactionEvent).toEqual(
+        expect.objectContaining({
+          contexts: expect.objectContaining({
+            trace: expect.objectContaining({
+              op: 'http.server',
+              data: expect.objectContaining({
+                'sentry.origin': 'auto.http.cloudflare',
+              }),
+              origin: 'auto.http.cloudflare',
+            }),
+          }),
+          transaction: 'GET /hello',
+        }),
+      );
+    })
+    .unordered()
+    .start(signal);
+  await runner.makeRequest('get', '/');
+  await runner.completed();
+});

dev-packages/cloudflare-integration-tests/suites/tracing/worker-service-binding/wrangler-sub-worker.jsonc

@@ -0,0 +1,9 @@
+{
+  "name": "cloudflare-service-binding-sub-worker",
+  "main": "index-sub-worker.ts",
+  "compatibility_date": "2025-06-17",
+  "compatibility_flags": ["nodejs_als"],
+  "vars": {
+    "SENTRY_DSN": "https://932e620ee3921c3b4a61c72558ad88ce@o447951.ingest.us.sentry.io/4509553159831552",
+  },
+}

dev-packages/cloudflare-integration-tests/suites/tracing/worker-service-binding/wrangler.jsonc

@@ -0,0 +1,15 @@
+{
+  "name": "cloudflare-worker-service-binding",
+  "main": "index.ts",
+  "compatibility_date": "2025-06-17",
+  "compatibility_flags": ["nodejs_als"],
+  "vars": {
+    "SENTRY_DSN": "https://932e620ee3921c3b4a61c72558ad88ce@o447951.ingest.us.sentry.io/4509553159831552",
+  },
+  "services": [
+    {
+      "binding": "ANOTHER_WORKER",
+      "service": "cloudflare-service-binding-sub-worker",
+    },
+  ],
+}