public void ShouldRateDataConsumptionWithReducedDataRating()
{
//Arrange
//TODO: avoid code duplication in tests
decimal reductionFactor = (decimal)0.5;
var callerNumber = new PhoneNumber("4530131514");
var receiverNumber = new PhoneNumber("4530202020");
var startTime = new DateTime(2014, 1, 9, 21, 10, 10);
var endTime = new DateTime(2014, 1, 9, 21, 20, 20);
var subscriptionId = new SubscriptionId(new Guid("b8e5bae2-76e7-49a8-b5ae-2cd0eb229b16"));
var dataConsumption = new DataConsumption(callerNumber, new Amount(30.0, Unit.MB), 1, startTime, subscriptionId);
var reducedDataRating = new ReducedDataRatingDecorator(new DataRating((decimal)3), reductionFactor);
//Act
var result = reducedDataRating.Rate(dataConsumption);
//Assert
Assert.Equal(30 * 3 * reductionFactor, result);
}
/// <summary>
/// Robert Martin actually suggests to put error handling in another method. Lets do that.
/// </summary>
/// <param name="consumption"></param>
/// <returns></returns>
public override decimal Rate(Consumption consumption)
{
if (!(consumption is DataConsumption))
{
throw new ArgumentException("consumption has to be of type DataConsumption", "consumption");
}
DataConsumption dataConsumption = (DataConsumption)consumption;
try{
return(DivideConsumptionByUnitSizeAndMultiplyWithUnitPrice(dataConsumption));
}
catch (DivideByZeroException dbze)
{
//handle specífic exception here. (We have actually guarded against UnitSize being zero.
throw dbze;
}
catch (Exception ex) // We might consider narrowing the scope of exceptions
{
//TODO: log exception, or handle it or just rethrow it.
throw ex;
}
}
/// <summary>
/// Errorhandling is handled in calling method
/// </summary>
/// <param name="dataConsumption"></param>
/// <returns></returns>
protected decimal DivideConsumptionByUnitSizeAndMultiplyWithUnitPrice(DataConsumption dataConsumption)
{
var result = ((decimal)dataConsumption.Amount.Value / dataConsumption.UnitSize) * UnitPrice;
return(result);
}
