public MainViewModel(BuyerPortfolio portfolio)
{
StartBuyingCommand = new Command(Join);
Buyers = new ObservableCollection <BuyerViewModel>();
_listeners = new List <IUserRequestListener>();
portfolio.AddPortfolioListener(this);
}
public void Notifies_listeners_of_new_buyers()
{
var sut = new BuyerPortfolio();
var mock = new Mock <IPortfolioListener>();
sut.AddPortfolioListener(mock.Object);
var buyer = new Buyer("ItemId", 10, 1, null);
sut.AddBuyer(buyer);
mock.Verify(x => x.BuyerAdded(buyer));
}