test(browser): Avoid making requests to http://example.com` (#15059)

The `http` version of example.com seems to have become unstable, even
for the preflight CORS requests the browser makes.
This PR adds a couple of `page.route` proxies to ensure we don't
actually send requests to example.com.

Also, I found a test which previously wasn't failing when the assertions
didn't pass

Author: Lms24

dev-packages/browser-integration-tests/suites/tracing/request/fetch-with-request/test.ts

@@ -10,21 +10,19 @@ sentryTest(
       sentryTest.skip();
     }
 
-    await page.route('**/api/test/', async route => {
-      const req = route.request();
-      const headers = await req.allHeaders();
-
-      // headers.bar was set in fetch options (and should be sent)
-      expect(headers.bar).toBe('22');
-      // headers.foo was set in init request object (and should be ignored)
-      expect(headers.foo).toBeUndefined();
-
-      return route.fulfill({
-        status: 200,
-        body: 'ok',
-      });
-    });
-
-    await getLocalTestUrl({ testDir: __dirname });
+    const requestPromise = page.waitForRequest('http://example.com/api/test/');
+
+    const url = await getLocalTestUrl({ testDir: __dirname });
+
+    await page.goto(url);
+
+    const request = await requestPromise;
+
+    const headers = await request.allHeaders();
+
+    // headers.bar was set in fetch options (and should be sent)
+    expect(headers.bar).toBe('22');
+    // headers.foo was set in init request object (and should be ignored)
+    expect(headers.foo).toBeUndefined();
   },
 );

dev-packages/browser-integration-tests/suites/tracing/request/fetch/test.ts

@@ -11,6 +11,8 @@ sentryTest('should create spans for fetch requests', async ({ getLocalTestUrl, p
     sentryTest.skip();
   }
 
+  await page.route('http://example.com/*', route => route.fulfill({ body: 'ok' }));
+
   const url = await getLocalTestUrl({ testDir: __dirname });
 
   const req = await waitForTransactionRequestOnUrl(page, url);
@@ -44,6 +46,8 @@ sentryTest('should attach `sentry-trace` header to fetch requests', async ({ get
     sentryTest.skip();
   }
 
+  await page.route('http://example.com/*', route => route.fulfill({ body: 'ok' }));
+
   const url = await getLocalTestUrl({ testDir: __dirname });
 
   const requests = (

dev-packages/browser-integration-tests/suites/tracing/request/xhr/test.ts

@@ -9,6 +9,8 @@ sentryTest('should create spans for XHR requests', async ({ getLocalTestUrl, pag
     sentryTest.skip();
   }
 
+  await page.route('http://example.com/*', route => route.fulfill({ body: 'ok' }));
+
   const url = await getLocalTestUrl({ testDir: __dirname });
 
   const eventData = await getFirstSentryEnvelopeRequest<Event>(page, url);