Cap laztRouteTimeout to finalTimeout

Author: onurtemizkan

dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/tests/timeout-behavior.test.ts renamed to dev-packages/e2e-tests/test-applications/react-router-7-lazy-routes/tests/timeout-behaviour.test.ts

@@ -35,7 +35,7 @@ test('lazyRouteTimeout: Infinity timeout always waits for routes', async ({ page
     );
   });
 
-  // Infinity timeout → waits however long needed
+  // Infinity timeout → waits as long as possible (capped at finalTimeout to prevent indefinite hangs)
   await page.goto('/?idleTimeout=50&timeout=Infinity');
 
   const navigationLink = page.locator('id=navigation-to-deep');
@@ -44,7 +44,7 @@ test('lazyRouteTimeout: Infinity timeout always waits for routes', async ({ page
 
   const event = await transactionPromise;
 
-  // Should wait indefinitely and get full route
+  // Should wait for routes to load (up to finalTimeout) and get full route
   expect(event.transaction).toBe('/deep/level2/level3/:id');
   expect(event.contexts?.trace?.data?.['sentry.source']).toBe('route');
   expect(event.contexts?.trace?.data?.['sentry.idle_span_finish_reason']).toBe('idleTimeout');

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

@@ -180,7 +180,7 @@ export interface ReactRouterOptions {
    * Maximum time (in milliseconds) to wait for lazy routes to load before finalizing span names.
    *
    * - Set to `0` to not wait at all (immediate finalization)
-   * - Set to `Infinity` to wait indefinitely
+   * - Set to `Infinity` to wait as long as possible (capped at `finalTimeout` to prevent indefinite hangs)
    * - Negative values will fall back to the default
    *
    * Defaults to 3× the configured `idleTimeout` (default: 3000ms).
@@ -562,11 +562,20 @@ export function createReactRouterV6CompatibleTracingIntegration(
     setup(client) {
       integration.setup(client);
 
+      const finalTimeout = options.finalTimeout ?? 30000;
       const defaultMaxWait = (options.idleTimeout ?? 1000) * 3;
       const configuredMaxWait = lazyRouteTimeout ?? defaultMaxWait;
 
-      // Validate and set
-      if (Number.isNaN(configuredMaxWait)) {
+      // Cap Infinity at finalTimeout to prevent indefinite hangs
+      if (configuredMaxWait === Infinity) {
+        _lazyRouteTimeout = finalTimeout;
+        DEBUG_BUILD &&
+          debug.log(
+            '[React Router] lazyRouteTimeout set to Infinity, capping at finalTimeout:',
+            finalTimeout,
+            'ms to prevent indefinite hangs',
+          );
+      } else if (Number.isNaN(configuredMaxWait)) {
         DEBUG_BUILD &&
           debug.warn('[React Router] lazyRouteTimeout must be a number, falling back to default:', defaultMaxWait);
         _lazyRouteTimeout = defaultMaxWait;