Some unconnected router setup

app.dart

class App extends HookConsumerWidget {
  const App({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final router = useMemoized(() => Router());
    final locale = ref.watch(localeProvider);

    return MaterialApp.router(
      debugShowCheckedModeBanner: !_kIsTakingScreenshots && kDebugMode,
      themeMode: ref.watch(themeModeProvider),
      locale: locale,
      onGenerateTitle: (context) {
        final localizations = AppLocalizations.of(context);

        return localizations?.title ?? '';
      },
      localizationsDelegates: const [
        ...AppLocalizations.localizationsDelegates,
        LocaleNamesLocalizationsDelegate(),
      ],
      supportedLocales: AppLocalizations.supportedLocales,
      routerDelegate: AutoRouterDelegate(
        router,
        navigatorObservers: () => [AutoRouteObserver()],
      ),
      routeInformationParser: router.defaultRouteParser(),
      builder: (context, child) {
        return UpgradeAlert(child: Unfocus(child: child));
      },
    );
  }
}

app_router.dart

class AppRouter extends HookWidget {
  const AppRouter({Key? key, required this.user}) : super(key: key);

  final User user;

  @override
  Widget build(BuildContext context) {
    final notifier = useMemoized(() => UserNotifier(user), [user]);

    return Material(
      // FIXME: Why doesn't this have a material at this point?
      // it also looks funky
      type: MaterialType.transparency,
      child: AutoRouter(
        builder: (context, child) {
          return HookConsumer(
            builder: (context, ref, _) {
              return ref.watch(maybeProfileDocProvider(user)).when(
                    data: (_profileDoc) {
                      if (_profileDoc.data() == null) {
                        return const NoProfile();
                      }

                      return child;
                    },
                    loading: defaultLoading,
                    error: defaultError,
                  );
            },
          );
        },
      ),
    );
  }
}

auth_provider.dart

final maybeUserProvider = StreamProvider.autoDispose<User?>((ref) {
  return FirebaseAuth.instance.authStateChanges();
});

auth_router.dart

class AuthRouter extends HookConsumerWidget {
  const AuthRouter({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final maybeUserValue = ref.watch(maybeUserProvider);

    return AutoRouter.declarative(
      routes: (BuildContext context) {
        return [
          maybeUserValue.when(
            data: (user) {
              if (user != null) {
                return AppRouterRoute(user: user);
              } else {
                return const AuthPageRoute();
              }
            },
            error: (error, stackTrace) => SplashPageRoute(
              error: error,
              stackTrace: stackTrace,
            ),
            loading: () => SplashPageRoute(),
          ),
        ];
      },
    );
  }
}

router.dart

@AdaptiveAutoRouter(
  // This is undocumented but it's the only way to get the router to not rebuild
  // ignore: unnecessary_const
  routes: const <AutoRoute>[
    AutoRoute<void>(
      page: AuthRouter,
      maintainState: true,
      path: '/',
      children: [
        AutoRoute<void>(
          path: 'splash',
          page: SplashPage,
        ),
        AutoRoute<void>(
          path: 'auth',
          page: AuthPage,
        ),
        AutoRoute<void>(
          path: 'app',
          initial: false,
          page: AppRouter,
          children: [
            AutoRoute<void>(
              path: '',
              page: HomePage,
              initial: true,
              children: [
                AutoRoute<void>(
                  path: 'practice',
                  page: PracticeTab,
                ),
                AutoRoute<void>(
                  path: 'learn',
                  page: LearnTab,
                ),
                AutoRoute<void>(
                  path: 'profile',
                  page: ProfileTab,
                ),
              ],
            ),
            // TODO: Evaluate if this works as expected
            AutoRoute<void>(
              path: ':postId',
              page: PostPage,
            ),
            AutoRoute<void>(
              path: ':groupId',
              page: GroupPostPage,
              children: [
                AutoRoute<void>(
                  path: ':postId',
                  page: PostPage,
                ),
              ],
            ),
            AutoRoute<void>(
              path: ':collectionId',
              page: CollectionPage,
            ),
            AutoRoute<void>(
              path: ':collectionId/:groupId/:postId',
              page: CollectionGroupPostPage,
            ),
            AutoRoute<Post>(
              path: 'add_post',
              page: AddDialog,
              fullscreenDialog: true,
            ),
            AutoRoute<void>(path: 'encounter', page: EnounterPage),
            AutoRoute<void>(path: 'about', page: AboutPage),
            AutoRoute<void>(path: 'terms_of_use', page: TermsOfUsePage),
            AutoRoute<void>(path: 'privacy_policy', page: PrivacyPolicyPage),
            AutoRoute<void>(path: 'settings', page: SettingsPage),
            AutoRoute<void>(path: 'purchase', page: PurchasePage),
          ],
        ),
      ],
    ),
    AutoRoute<void>(path: '*', page: UnknownRoutePage),
  ],
)
class $Router {}