Invalid argument(s): Object/factory with type XXX is already registered inside GetIt.

[redsuperbat]

Trying to run this codeblock to register a singleton in getit. The console prints "Trying to register navigator" which indicates that the instance is not registered. However when getit the tries to register the singleton it throws.

final navigator = LandingPageNavigator(guards: model.routerGuards);
if (!GetIt.I.isRegistered(instance: LandingPageNavigator)) {
  print("Trying to register navigator");
  GetIt.I.registerSingleton<LandingPageNavigator>(navigator);
}

Stacktrace:

I/flutter ( 3418): Trying to register navigator
════════ Exception caught by widgets library ═══════════════════════════════════
The following ArgumentError was thrown building BaseWidget<LandingModel>(dirty, state: _BaseWidgetState<LandingModel>#ad5e0):
Invalid argument(s): Object/factory with  type LandingPageNavigator is already registered inside GetIt.

The relevant error-causing widget was
BaseWidget<LandingModel>
package:wine_cellar/…/landing-page/landing-page.dart:12
When the exception was thrown, this was the stack
#0      throwIf
package:get_it/get_it_impl.dart:7
#1      _GetItImplementation._register
package:get_it/get_it_impl.dart:675
#2      _GetItImplementation.registerLazySingleton
package:get_it/get_it_impl.dart:455
#3      LandingPage.build.<anonymous closure>
package:wine_cellar/…/landing-page/landing-page.dart:18
#4      _BaseWidgetState.build
package:wine_cellar/pages/base-widget.dart:43
...
════════════════════════════════════════════════════════════════════════════════

[escamoteur]

This throws on the first time this part of code is executed? That should be impossible.

But your check if your singleton is registered is wrong. you are passing a type as instance. The instance parameter is only if you want to check if an existing Object is already registered.
You probably want this here:

final navigator = LandingPageNavigator(guards: model.routerGuards);
if (!GetIt.I.isRegistered<LandingPageNavigator>()) {
  print("Trying to register navigator");
  GetIt.I.registerSingleton<LandingPageNavigator>(navigator);
}

[redsuperbat]

Ah geez, that was the problem. Thanks for the quick response! =)

Should have noticed i was passing a type and not the actual instance. My bad.