[go_router] Fix: guard empty matches in _findCurrentNavigators and popRoute

packages/go_router/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 17.3.1
+
+- Fixes `popRoute()` crashing with `Bad state: No element` when
+  `currentConfiguration` is empty (e.g. during app startup before
+  the first route resolves).
+
 ## 17.3.0
 
 - Updates minimum supported SDK version to Flutter 3.38/Dart 3.10.

packages/go_router/lib/src/delegate.dart

@@ -61,7 +61,9 @@ class GoRouterDelegate extends RouterDelegate<RouteMatchList> with ChangeNotifie
         return true; // Return true if maybePop handled the pop
       }
     }
-
+    if (currentConfiguration.isEmpty) {
+      return false;
+    }
     // Fallback to onExit if maybePop did not handle the pop
     final GoRoute lastRoute = currentConfiguration.last.route;
     if (lastRoute.onExit != null && navigatorKey.currentContext != null) {
@@ -79,7 +81,7 @@ class GoRouterDelegate extends RouterDelegate<RouteMatchList> with ChangeNotifie
     if (navigatorKey.currentState?.canPop() ?? false) {
       return true;
     }
-    if (currentConfiguration.matches.isEmpty) {
+    if (currentConfiguration.isEmpty) {
       return false;
     }
     RouteMatchBase walker = currentConfiguration.matches.last;
@@ -115,7 +117,9 @@ class GoRouterDelegate extends RouterDelegate<RouteMatchList> with ChangeNotifie
       // Set state directly without canPop check
       states.add(navigatorKey.currentState!);
     }
-
+    if (currentConfiguration.isEmpty) {
+      return states.reversed;
+    }
     RouteMatchBase walker = currentConfiguration.matches.last;
     while (walker is ShellRouteMatch) {
       final NavigatorState potentialCandidate = walker.navigatorKey.currentState!;

packages/go_router/pubspec.yaml

@@ -1,7 +1,7 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 17.3.0
+version: 17.3.1
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22
 

packages/go_router/test/delegate_test.dart

@@ -345,6 +345,23 @@ void main() {
     });
   });
 
+  testWidgets('popRoute does not throw Bad state when currentConfiguration is empty', (
+    WidgetTester tester,
+  ) async {
+    final GoRouter goRouter = GoRouter(
+      initialLocation: '/',
+      routes: <GoRoute>[GoRoute(path: '/', builder: (_, _) => const DummyStatefulWidget())],
+    );
+    addTearDown(goRouter.dispose);
+    await tester.pumpWidget(MaterialApp.router(routerConfig: goRouter));
+
+    // Simulate empty configuration (e.g. startup window before first route resolves)
+    goRouter.routerDelegate.currentConfiguration = RouteMatchList.empty;
+
+    // Should return false without throwing "Bad state: No element"
+    expect(await goRouter.routerDelegate.popRoute(), isFalse);
+  });
+
   group('push', () {
     testWidgets('It should return different pageKey when push is called', (
       WidgetTester tester,