test(test-utils): Add MemoryProfiler for heap snapshot testing via CDP

Author: JPeer264

dev-packages/e2e-tests/test-applications/cloudflare-workers/.gitignore

@@ -1 +1,2 @@
 .wrangler
+heap-snapshots

dev-packages/e2e-tests/test-applications/cloudflare-workers/package.json

@@ -24,8 +24,7 @@
     "@sentry-internal/test-utils": "link:../../../test-utils",
     "typescript": "^5.5.2",
     "vitest": "~3.2.0",
-    "wrangler": "^4.61.0",
-    "ws": "^8.18.3"
+    "wrangler": "^4.61.0"
   },
   "volta": {
     "extends": "../../package.json"

dev-packages/e2e-tests/test-applications/cloudflare-workers/playwright.config.ts

@@ -6,10 +6,12 @@ if (!testEnv) {
 }
 
 const APP_PORT = 38787;
+const INSPECTOR_PORT = 9230;
 
 const config = getPlaywrightConfig(
   {
-    startCommand: `pnpm dev --port ${APP_PORT}`,
+    // Enable inspector port for memory profiling tests via CDP
+    startCommand: `pnpm dev --port ${APP_PORT} --inspector-port ${INSPECTOR_PORT}`,
     port: APP_PORT,
   },
   {

dev-packages/e2e-tests/test-applications/cloudflare-workers/tests/memory.test.ts

@@ -0,0 +1,54 @@
+import { MemoryProfiler } from '@sentry-internal/test-utils';
+import { expect, test } from '@playwright/test';
+import * as path from 'path';
+
+/**
+ * Memory leak tests for Cloudflare Workers SDK.
+ *
+ * These tests verify that the CloudflareClient.dispose() mechanism properly
+ * cleans up resources to prevent memory leaks.
+ *
+ * The test connects directly to the wrangler dev server's V8 inspector via CDP
+ * (Chrome DevTools Protocol) on ws://127.0.0.1:9230/ws to take heap snapshots
+ * of the actual worker isolate.
+ *
+ * @see https://developers.cloudflare.com/workers/observability/dev-tools/memory-usage/
+ */
+
+// Wrangler dev exposes inspector on this port (configured in playwright.config.ts)
+const INSPECTOR_PORT = 9230;
+
+/**
+ * CDP-based heap snapshot test for Cloudflare Workers.
+ *
+ * This test connects directly to the wrangler dev inspector at ws://127.0.0.1:9230/ws
+ * to profile the actual worker's V8 isolate memory, not a browser.
+ *
+ * The wrangler dev server must be running with --inspector-port 9230.
+ * This is configured in playwright.config.ts.
+ */
+test.describe('Worker V8 isolate memory tests', () => {
+  // Heap snapshot serialization for the worker isolate can take 30s+ on top of the requests.
+  test.setTimeout(120_000);
+
+  test('worker memory is reclaimed after GC', async ({ baseURL }) => {
+    const profiler = new MemoryProfiler({ port: INSPECTOR_PORT, debug: true });
+
+    await profiler.connect();
+    await profiler.startProfiling();
+
+    const numRequests = 50;
+
+    for (let i = 0; i < numRequests; i++) {
+      const res = await fetch(baseURL!);
+      expect(res.status).toBe(200);
+      await res.text();
+    }
+
+    const result = await profiler.stopProfiling();
+
+    expect(result.growthKB).toBeLessThan(50);
+
+    await profiler.close();
+  });
+});

dev-packages/test-utils/package.json

@@ -44,11 +44,13 @@
     "@playwright/test": "~1.56.0"
   },
   "dependencies": {
-    "express": "^4.21.2"
+    "express": "^4.21.2",
+    "ws": "^8.18.0"
   },
   "devDependencies": {
     "@playwright/test": "~1.56.0",
     "@sentry/core": "10.50.0",
+    "@types/ws": "^8.5.10",
     "eslint-plugin-regexp": "^1.15.0"
   },
   "volta": {