test(core): Cover attachStacktrace opt-out; clarify option docs

Add browser + node integration suites asserting `attachStacktrace: false`
produces no stack trace, and reword the option JSDoc to reflect that it also
applies to non-Error values passed to captureException.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: nicohrubec

dev-packages/browser-integration-tests/suites/public-api/captureMessage/simple_message_no_stacktrace/init.js

@@ -0,0 +1,8 @@
+import * as Sentry from '@sentry/browser';
+
+window.Sentry = Sentry;
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  attachStacktrace: false,
+});

dev-packages/browser-integration-tests/suites/public-api/captureMessage/simple_message_no_stacktrace/subject.js

@@ -0,0 +1 @@
+Sentry.captureMessage('foo');

dev-packages/browser-integration-tests/suites/public-api/captureMessage/simple_message_no_stacktrace/test.ts

@@ -0,0 +1,14 @@
+import { expect } from '@playwright/test';
+import type { Event } from '@sentry/core';
+import { sentryTest } from '../../../../utils/fixtures';
+import { getFirstSentryEnvelopeRequest } from '../../../../utils/helpers';
+
+sentryTest('does not capture a stack trace if `attachStackTrace` is `false`', async ({ getLocalTestUrl, page }) => {
+  const url = await getLocalTestUrl({ testDir: __dirname });
+
+  const eventData = await getFirstSentryEnvelopeRequest<Event>(page, url);
+
+  expect(eventData.message).toBe('foo');
+  expect(eventData.level).toBe('info');
+  expect(eventData.exception).toBeUndefined();
+});

dev-packages/node-integration-tests/suites/public-api/captureMessage/simple_message_no_stacktrace/scenario.ts

@@ -0,0 +1,11 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  transport: loggingTransport,
+  attachStacktrace: false,
+});
+
+Sentry.captureMessage('Message');

dev-packages/node-integration-tests/suites/public-api/captureMessage/simple_message_no_stacktrace/test.ts

@@ -0,0 +1,19 @@
+import { afterAll, expect, test } from 'vitest';
+import { cleanupChildProcesses, createRunner } from '../../../../utils/runner';
+
+afterAll(() => {
+  cleanupChildProcesses();
+});
+
+test('does not capture a stack trace if `attachStackTrace` is `false`', async () => {
+  await createRunner(__dirname, 'scenario.ts')
+    .expect({
+      event: event => {
+        expect(event.message).toBe('Message');
+        expect(event.level).toBe('info');
+        expect(event.exception).toBeUndefined();
+      },
+    })
+    .start()
+    .completed();
+});

packages/core/src/types/options.ts

@@ -182,8 +182,9 @@ export interface ClientOptions<TO extends BaseTransportOptions = BaseTransportOp
   enabled?: boolean;
 
   /**
-   * Stack traces are automatically attached to all events captured with `Sentry.captureMessage`.
-   * Set this to `false` to disable attaching stack traces to these events.
+   * Stack traces are automatically attached to events that don't otherwise have one. This applies
+   * to events captured with `Sentry.captureMessage` and to non-Error values passed to
+   * `Sentry.captureException`. Set this to `false` to disable attaching these stack traces.
    *
    * Grouping in Sentry is different for events with stack traces and without. As a result, you will get
    * new groups as you enable or disable this flag for certain events.