//methods
public async Task <CommandResult <AddUserOutputModel> > AddUserAsync(AddUserInputModel inputModel)
{
_inputModel = inputModel ?? throw new ArgumentNullException(nameof(inputModel));
_userToAdd = new User(inputModel.ToUserModel());
if (!_userToAdd.IsValid)
{
return(PresentValidationErrors());
}
if (await IsUserAlreadyStoredAsync(_userToAdd))
{
return(PresentDuplicatedResult(new AddUserOutputModel(_userToAdd.GetModel())));
}
_userToAdd = await SaveToStorageAsync();
return(PresentSuccessfulResult());
}
