test(node): Cover httpIntegration outgoing request span hooks

`outgoingRequestHook`, `outgoingResponseHook` and
`outgoingRequestApplyCustomAttributes` had no coverage after #23396 dropped the
incoming `instrumentation.*` assertions without replacing the outgoing side.

Each hook derives its attribute from the objects it is handed, so a hook wired
to the wrong span, request or response fails rather than passing silently.

Author: RulaKhaled

dev-packages/node-integration-tests/suites/tracing/httpIntegration/server-outgoingHooks.js

@@ -0,0 +1,64 @@
+const { loggingTransport } = require('@sentry-internal/node-integration-tests');
+const Sentry = require('@sentry/node');
+
+const url = process.env.SERVER_URL;
+
+Sentry.init({
+  traceLifecycle: 'static',
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  transport: loggingTransport,
+
+  integrations: [
+    Sentry.httpIntegration({
+      // Each hook derives its attribute from the objects it is handed, so a hook that fires with
+      // the wrong span, request or response fails the assertion rather than passing silently.
+      outgoingRequestHook: (span, request) => {
+        span.setAttribute('outgoingRequestHook', request.method);
+      },
+      outgoingResponseHook: (span, response) => {
+        span.setAttribute('outgoingResponseHook', response.statusCode);
+      },
+      outgoingRequestApplyCustomAttributes: (span, request, response) => {
+        span.setAttribute('outgoingRequestApplyCustomAttributes', `${request.method} ${response.statusCode}`);
+      },
+    }),
+  ],
+});
+
+const http = require('http');
+
+// express must be required after Sentry is initialized
+const express = require('express');
+const cors = require('cors');
+const { startExpressServerAndSendPortToRunner } = require('@sentry-internal/node-integration-tests');
+
+const app = express();
+
+app.use(cors());
+
+app.get('/testOutgoing', (_req, response) => {
+  makeHttpRequest(`${url}/api/users/42`).then(() => {
+    response.send({ response: 'done' });
+  });
+});
+
+Sentry.setupExpressErrorHandler(app);
+
+startExpressServerAndSendPortToRunner(app);
+
+function makeHttpRequest(url) {
+  return new Promise((resolve, reject) => {
+    http
+      .get(url, res => {
+        res.on('data', () => {});
+        res.on('end', () => {
+          resolve();
+        });
+      })
+      .on('error', error => {
+        reject(error);
+      });
+  });
+}

dev-packages/node-integration-tests/suites/tracing/httpIntegration/test.ts

@@ -56,6 +56,33 @@ describe('httpIntegration', () => {
     });
   });
 
+  describe('outgoing request span hooks', () => {
+    test('runs outgoingRequestHook, outgoingResponseHook and outgoingRequestApplyCustomAttributes', async () => {
+      const [SERVER_URL, closeTestServer] = await createTestServer()
+        .get('/api/users/42', () => {}, 200)
+        .start();
+
+      const runner = createRunner(__dirname, 'server-outgoingHooks.js')
+        .withEnv({ SERVER_URL })
+        .expect({
+          transaction: event => {
+            const clientSpans = event.spans?.filter(span => span.op === 'http.client');
+            expect(clientSpans).toHaveLength(1);
+
+            // All three hooks run before the span ends, so every attribute has to survive to the envelope.
+            const data = clientSpans![0]?.data;
+            expect(data?.['outgoingRequestHook']).toBe('GET');
+            expect(data?.['outgoingResponseHook']).toBe(200);
+            expect(data?.['outgoingRequestApplyCustomAttributes']).toBe('GET 200');
+          },
+        })
+        .start();
+      runner.makeRequest('get', '/testOutgoing');
+      await runner.completed();
+      closeTestServer();
+    });
+  });
+
   describe('http.server spans', () => {
     createEsmAndCjsTests(__dirname, 'server.mjs', 'instrument.mjs', (createRunner, test) => {
       test('captures correct attributes for GET requests', async () => {