Address remaining PR review comments

Author: onurtemizkan

packages/react/src/reactrouter-compat-utils/instrumentation.tsx

@@ -731,7 +731,12 @@ function wrapPatchRoutesOnNavigation(
           (args as any).patch = (routeId: string, children: RouteObject[]) => {
             addRoutesToAllRoutes(children);
             const currentActiveRootSpan = getActiveRootSpan();
-            if (currentActiveRootSpan && (spanToJSON(currentActiveRootSpan) as { op?: string }).op === 'navigation') {
+            // Only update if we have a valid targetPath (patchRoutesOnNavigation can be called without path)
+            if (
+              targetPath &&
+              currentActiveRootSpan &&
+              (spanToJSON(currentActiveRootSpan) as { op?: string }).op === 'navigation'
+            ) {
               updateNavigationSpan(
                 currentActiveRootSpan,
                 { pathname: targetPath, search: '', hash: '', state: null, key: 'default' },

packages/react/src/reactrouter-compat-utils/utils.ts

@@ -48,6 +48,7 @@ export function clearNavigationContext(token: object): void {
 /** Gets the current (most recent) navigation context if inside a patchRoutesOnNavigation call. */
 export function getNavigationContext(): NavigationContext | null {
   const length = _navigationContextStack.length;
+  // The `?? null` converts undefined (from array access) to null to match return type
   return length > 0 ? (_navigationContextStack[length - 1] ?? null) : null;
 }