type 'Null' is not a subtype of type 'String'

[amkfat]

i'm using a new version of flutter
i get this error: type 'Null' is not a subtype of type 'String'

at the 3rd this line of the code (plan_services.dart):

  Plan createPlan(String name) {
    final model = _repository.create();
    print('my name $name');                                           //the name in not null here
    final plan = Plan.fromModel(model)..name = name;            //error here
    savePlan(plan);
    return plan;
  }

after debugging, i got name=null here (plan.dart)

  Plan.fromModel(Model model)
      : id = model.id,
        name = model.data['name'],             //the name is null here
        tasks = model.data['task']
                ?.map<Task>((task) => Task.fromModel(task))
                ?.toList() ??
            <Task>[];

can you explain why? thank you

[rajat-packt]

Hey @amkfat can you please also provide the chapter and page number of the exercise you are following? We will try to reach out to author and provide you with an explanation and resolution for your queries.