How to use dart shelf_router in web only dart project - dart

Question

From the example given at this place :
https://pub.dev/packages/shelf_router/example
I have written the router part like this :
class Service {
Handler get handler {
final router = Router();
router.get('/say-hi/<name>', (Request request, String name) {
return Response.ok('hi $name');
});
router.get('/user/<userId|[0-9]+>', (Request request, String userId) {
return Response.ok('User has the user-number: $userId');
});
router.get('/wave', (Request request) async {
await Future.delayed(Duration(milliseconds: 100));
return Response.ok('_o/');
});
router.mount('/api/', Api().router);
router.all('/<ignored|.*>', (Request request) {
return Response.notFound('Page not found');
});
return router;
}
}
class Api {
Future<Response> _messages(Request request) async {
return Response.ok('[]');
}
Router get router {
final router = Router();
router.get('/messages', _messages);
router.get('/messages/', _messages);
uter.all('/<ignored|.*>', (Request request) => Response.notFound('null'));
return router;
}
}
and from the main method it tells to use it like this:
void main() async {
final service = Service();
final server = await shelf_io.serve(service.handler, 'localhost', 8080);
print('Server running on localhost:${server.port}');
}
but in web-only project we don't do : final server = await shelf_io.serve(service.handler, 'localhost', 8080);
I was thinking of creating single page application using a shelf router, I saw from the documentation it says that it is compatible with the dart web js platform
My expectation was :
if I write this in web :
router.get('/say-hi/<name>', (Request request, String name) {
return Response.ok('hi $name');
});
then when I will hit /say-hi/ram, then it should have returned "hi ram" in the browser