test(browser): Add test showing behavior of capturing built-in class instances (#16638)

This is not really ideal, but there is no great alternative for this
that I can think of to handle this generically 😬

Now at least we have a test showing the current behavior!

Author: mydea

dev-packages/browser-integration-tests/suites/public-api/captureException/builtInClassInstance/subject.js

@@ -0,0 +1 @@
+Sentry.captureException(new Response('test body'));

dev-packages/browser-integration-tests/suites/public-api/captureException/builtInClassInstance/test.ts

@@ -0,0 +1,20 @@
+import { expect } from '@playwright/test';
+import type { Event } from '@sentry/core';
+import { sentryTest } from '../../../../utils/fixtures';
+import { getFirstSentryEnvelopeRequest } from '../../../../utils/helpers';
+
+sentryTest('should capture a class instance of a built-in class', async ({ getLocalTestUrl, page }) => {
+  const url = await getLocalTestUrl({ testDir: __dirname });
+
+  const eventData = await getFirstSentryEnvelopeRequest<Event>(page, url);
+
+  expect(eventData.exception?.values).toHaveLength(1);
+  expect(eventData.exception?.values?.[0]).toMatchObject({
+    type: 'Error',
+    value: '[object Response]',
+    mechanism: {
+      type: 'generic',
+      handled: true,
+    },
+  });
+});

dev-packages/browser-integration-tests/suites/public-api/captureException/classInstance/test.ts

@@ -3,7 +3,7 @@ import type { Event } from '@sentry/core';
 import { sentryTest } from '../../../../utils/fixtures';
 import { getFirstSentryEnvelopeRequest } from '../../../../utils/helpers';
 
-sentryTest('should capture an POJO', async ({ getLocalTestUrl, page }) => {
+sentryTest('should capture an class instance', async ({ getLocalTestUrl, page }) => {
   const url = await getLocalTestUrl({ testDir: __dirname });
 
   const eventData = await getFirstSentryEnvelopeRequest<Event>(page, url);