public void BalanceAfterVendingTest()
{
//arrange
var vendingmachine = new VendingMachine(MaxCups, accountServer);
IAccount account;
accountServer.ValidateCard(card1.CardNo, card1.Pin, out account);
var prevBalance = account.Balance();
//act
string message;
var isSuccess = vendingmachine.Vend(card1.CardNo, card1.Pin, softdrink, out message);
var currentBalance = account.Balance();
Assert.IsTrue(prevBalance - currentBalance == softdrink.Cost, "Card balance not updated after vending");
//assert
var testMsg = $"Vending success Test - Message returned = {message}";
Assert.IsTrue(isSuccess, testMsg);
}
