public AtmMachine(IWithdrawalStrategy withdrawalStrategy, IAtmInventory atmInventory)
{
if (withdrawalStrategy == null)
{
throw new ArgumentNullException(nameof(withdrawalStrategy));
}
if (atmInventory == null)
{
throw new ArgumentNullException(nameof(atmInventory));
}
_withdrawalStrategy = withdrawalStrategy;
_atmInventory = atmInventory;
}
public void ConstructWithNullInventoryShouldThrow()
{
// Arrange
var testWithdrawalStrategy = new Moq.Mock <IWithdrawalStrategy>();
IAtmInventory testInventory = null;
// Act
var actualException = Assert.Throws <ArgumentNullException>(() => {
#pragma warning disable RECS0026 // Possible unassigned object created by 'new'
new ATMMachine.Entities.AtmMachine(testWithdrawalStrategy.Object, testInventory);
#pragma warning restore RECS0026 // Possible unassigned object created by 'new'
});
// Assert
Assert.Contains("Value cannot be null", actualException.Message);
}
public IWithdrawalResult Withdraw(int amount, IAtmInventory inventory)
{
var withdrawTransaction = CashTransaction.Start();
var descendingUnitedStatesTenders = UnitedStatesTender.GetAllDefinedTenders().OrderByDescending(tender => tender.Value);
var transactionAmount = amount;
foreach (var tender in descendingUnitedStatesTenders)
{
var numberOfBills = transactionAmount / tender.Value;
if (numberOfBills > 0)
{
withdrawTransaction.Add(tender, numberOfBills);
transactionAmount = transactionAmount - tender.GetValue(numberOfBills);
}
if (transactionAmount == 0)
{
break;
}
if (transactionAmount < 0)
{
throw new ApplicationException($"transaction amount has gone below zero!");
}
}
// Does inventory support transaction
var isPossible = inventory.Withdraw(withdrawTransaction);
if (isPossible)
{
return(WithdrawalResult.CreateSuccessResult(withdrawTransaction));
}
else
{
return(WithdrawalResult.CreateFailureResult("insufficient funds", withdrawTransaction));
}
}
