feat(nextjs): Always add browserTracingIntegration (#13324)

closes #13012

ref: #13323

Author: s1gr1d

.size-limit.js

@@ -193,7 +193,7 @@ module.exports = [
     import: createImport('init'),
     ignore: ['next/router', 'next/constants'],
     gzip: true,
-    limit: '38.03 KB',
+    limit: '38.05 KB',
   },
   // SvelteKit SDK (ESM)
   {

packages/nextjs/src/client/index.ts

@@ -1,4 +1,4 @@
-import { addEventProcessor, applySdkMetadata, hasTracingEnabled } from '@sentry/core';
+import { addEventProcessor, applySdkMetadata } from '@sentry/core';
 import type { BrowserOptions } from '@sentry/react';
 import { getDefaultIntegrations as getReactDefaultIntegrations, init as reactInit } from '@sentry/react';
 import type { Client, EventProcessor, Integration } from '@sentry/types';
@@ -48,13 +48,10 @@ export function init(options: BrowserOptions): Client | undefined {
 
 function getDefaultIntegrations(options: BrowserOptions): Integration[] {
   const customDefaultIntegrations = getReactDefaultIntegrations(options);
-
-  // This evaluates to true unless __SENTRY_TRACING__ is text-replaced with "false", in which case everything inside
-  // will get treeshaken away
+  // This evaluates to true unless __SENTRY_TRACING__ is text-replaced with "false",
+  // in which case everything inside will get tree-shaken away
   if (typeof __SENTRY_TRACING__ === 'undefined' || __SENTRY_TRACING__) {
-    if (hasTracingEnabled(options)) {
-      customDefaultIntegrations.push(browserTracingIntegration());
-    }
+    customDefaultIntegrations.push(browserTracingIntegration());
   }
 
   // This value is injected at build time, based on the output directory specified in the build config. Though a default

packages/nextjs/test/clientSdk.test.ts

@@ -130,33 +130,28 @@ describe('Client init()', () => {
     });
 
     describe('browserTracingIntegration()', () => {
-      it('adds `browserTracingIntegration()` integration if `tracesSampleRate` is set', () => {
+      it('adds the browserTracingIntegration when `__SENTRY_TRACING__` is not set', () => {
         const client = init({
           dsn: TEST_DSN,
-          tracesSampleRate: 1.0,
         });
 
         const browserTracingIntegration = client?.getIntegrationByName('BrowserTracing');
-        expect(browserTracingIntegration?.name).toBe('BrowserTracing');
+        expect(browserTracingIntegration).toBeDefined();
       });
 
-      it('adds `browserTracingIntegration()` integration if `tracesSampler` is set', () => {
-        const client = init({
-          dsn: TEST_DSN,
-          tracesSampler: () => true,
-        });
+      it("doesn't add a browserTracingIntegration if `__SENTRY_TRACING__` is set to false", () => {
+        // @ts-expect-error Test setup for build-time flag
+        globalThis.__SENTRY_TRACING__ = false;
 
-        const browserTracingIntegration = client?.getIntegrationByName('BrowserTracing');
-        expect(browserTracingIntegration?.name).toBe('BrowserTracing');
-      });
-
-      it('does not add `browserTracingIntegration()` integration if tracing not enabled in SDK', () => {
         const client = init({
           dsn: TEST_DSN,
         });
 
         const browserTracingIntegration = client?.getIntegrationByName('BrowserTracing');
         expect(browserTracingIntegration).toBeUndefined();
+
+        // @ts-expect-error Test setup for build-time flag
+        delete globalThis.__SENTRY_TRACING__;
       });
     });
   });