fix(nextjs): Preserve next.route attribute on root spans (#16297)

Author: chargome

dev-packages/e2e-tests/test-applications/nextjs-app-dir/tests/server-components.test.ts

@@ -25,6 +25,7 @@ test('Sends a transaction for a request to app router', async ({ page }) => {
       'http.status_code': 200,
       'http.target': '/server-component/parameter/1337/42',
       'otel.kind': 'SERVER',
+      'next.route': '/server-component/parameter/[...parameters]',
     }),
     op: 'http.server',
     origin: 'auto',

packages/nextjs/src/server/index.ts

@@ -176,6 +176,8 @@ export function init(options: NodeOptions): NodeClient | undefined {
         const route = spanAttributes['next.route'].replace(/\/route$/, '');
         rootSpan.updateName(route);
         rootSpan.setAttribute(ATTR_HTTP_ROUTE, route);
+        // Preserving the original attribute despite internally not depending on it
+        rootSpan.setAttribute('next.route', route);
       }
     }
 
@@ -322,11 +324,14 @@ export function init(options: NodeOptions): NodeClient | undefined {
       const method = event.contexts.trace.data[SEMATTRS_HTTP_METHOD];
       // eslint-disable-next-line deprecation/deprecation
       const target = event.contexts?.trace?.data?.[SEMATTRS_HTTP_TARGET];
-      const route = event.contexts.trace.data[ATTR_HTTP_ROUTE];
+      const route = event.contexts.trace.data[ATTR_HTTP_ROUTE] || event.contexts.trace.data['next.route'];
 
       if (typeof method === 'string' && typeof route === 'string') {
-        event.transaction = `${method} ${route.replace(/\/route$/, '')}`;
+        const cleanRoute = route.replace(/\/route$/, '');
+        event.transaction = `${method} ${cleanRoute}`;
         event.contexts.trace.data[SEMANTIC_ATTRIBUTE_SENTRY_SOURCE] = 'route';
+        // Preserve next.route in case it did not get hoisted
+        event.contexts.trace.data['next.route'] = cleanRoute;
       }
 
       // backfill transaction name for pages that would otherwise contain unparameterized routes