fix(nextjs): Don't report React postpone errors

dev-packages/e2e-tests/test-applications/nextjs-15/app/ppr-error/[param]/page.tsx

@@ -0,0 +1,18 @@
+import * as Sentry from '@sentry/nextjs';
+
+export default async function Page({
+  searchParams,
+}: {
+  searchParams: { id?: string };
+}) {
+  try {
+    console.log(searchParams.id); // Accessing a field on searchParams will throw the PPR error
+  } catch (e) {
+    Sentry.captureException(e); // This error should not be reported
+    await new Promise(resolve => setTimeout(resolve, 1000)); // Wait for any async event processors to run
+    await Sentry.flush();
+    throw e;
+  }
+
+  return <div>This server component will throw a PPR error that we do not want to catch.</div>;
+}

dev-packages/e2e-tests/test-applications/nextjs-15/next.config.js

@@ -1,7 +1,11 @@
 const { withSentryConfig } = require('@sentry/nextjs');
 
 /** @type {import('next').NextConfig} */
-const nextConfig = {};
+const nextConfig = {
+  experimental: {
+    ppr: true,
+  },
+};
 
 module.exports = withSentryConfig(nextConfig, {
   silent: true,

dev-packages/e2e-tests/test-applications/nextjs-15/tests/ppr-error.test.ts

@@ -0,0 +1,22 @@
+import { expect, test } from '@playwright/test';
+import { waitForError, waitForTransaction } from '@sentry-internal/event-proxy-server';
+
+test('should not capture React-internal errors for PPR rendering', async ({ page }) => {
+  const pageServerComponentTransactionPromise = waitForTransaction('nextjs-15', async transactionEvent => {
+    return transactionEvent?.transaction === 'Page Server Component (/ppr-error/[param])';
+  });
+
+  let errorEventReceived = false;
+  waitForError('nextjs-15', async transactionEvent => {
+    return transactionEvent?.transaction === 'Page Server Component (/ppr-error/[param])';
+  }).then(() => {
+    errorEventReceived = true;
+  });
+
+  await page.goto(`/ppr-error/foobar?id=1`);
+
+  const pageServerComponentTransaction = await pageServerComponentTransactionPromise;
+  expect(pageServerComponentTransaction).toBeDefined();
+
+  expect(errorEventReceived).toBe(false);
+});

packages/nextjs/src/server/index.ts

@@ -1,4 +1,4 @@
-import { addEventProcessor, applySdkMetadata, getClient } from '@sentry/core';
+import { addEventProcessor, applySdkMetadata, getClient, getGlobalScope } from '@sentry/core';
 import { getDefaultIntegrations, init as nodeInit } from '@sentry/node';
 import type { NodeOptions } from '@sentry/node';
 import { GLOBAL_OBJ, logger } from '@sentry/utils';
@@ -181,6 +181,31 @@ export function init(options: NodeOptions): void {
     ),
   );
 
+  getGlobalScope().addEventProcessor(
+    Object.assign(
+      ((event, hint) => {
+        if (event.type !== undefined) {
+          return event;
+        }
+
+        const originalException = hint.originalException;
+
+        const isReactControlFlowError =
+          typeof originalException === 'object' &&
+          originalException !== null &&
+          '$$typeof' in originalException &&
+          originalException.$$typeof === Symbol.for('react.postpone');
+
+        if (isReactControlFlowError) {
+          return null;
+        }
+
+        return event;
+      }) satisfies EventProcessor,
+      { id: 'DropReactControlFlowErrors' },
+    ),
+  );
+
   if (process.env.NODE_ENV === 'development') {
     addEventProcessor(devErrorSymbolicationEventProcessor);
   }