public void AnnualPowerUsage_TariffWithNoGas_ReturnsNothing()
{
// Arrange
var tariff = new Tariff("test", null, null, 3m);
// Act
var actual = FuelCalculator.AnnualPowerUsage(tariff, TaxedValue.FromPreTaxValue(100, x => x));
// Assert
actual.HasValue.Should().BeFalse();
}
public void AnnualPowerUsage_TariffWithGas_ReturnsUsage()
{
// Arrange
var tariff = new Tariff("test", 2m, null, 3m);
// Act
var actual = FuelCalculator.AnnualPowerUsage(tariff, TaxedValue.FromPreTaxValue(100, x => x));
// Assert
actual.HasValue.Should().BeTrue();
actual.Value.Value.Should().Be((100 - 3) * 12 * 2);
}
public UsageCommand(ITariffSource source)
{
Spec = CommandSpec.Named(
"usage",
new[] { "TARIFF_NAME", "FUEL_TYPE", "TARGET_MONTHLY_SPEND" },
ctx =>
{
var tariffName = ctx.GetRequiredString("TARIFF_NAME");
var fuelType = ctx.GetRequiredEnum <FuelType>("FUEL_TYPE");
var monthlyBudget = TaxedValue.FromPostTaxValue(
ctx.GetRequiredDecimal("TARGET_MONTHLY_SPEND"),
TaxHelper.RemoveTax);
if (!source.TryGet(tariffName, out var tariff))
{
return(Commands.Error($"The specified tariff doesn't exist '{tariffName}'."));
}
// c# has no proper pattern matching, so I've run out of functional luck here, apologies for the switch statement...
switch (fuelType)
{
case FuelType.Gas:
if (!tariff.GasRate.HasValue)
{
return(Commands.Error($"Tariff '{tariff.Name}' does not include {FuelType.Gas}."));
}
ctx.Output.WriteLine(
FuelCalculator.AnnualGasUsage(tariff, monthlyBudget).GetValueOrDefault().Value); // just output 0 if tariff doesn't include fuel type
break;
case FuelType.Power:
if (!tariff.PowerRate.HasValue)
{
return(Commands.Error($"Tariff '{tariff.Name}' does not include {FuelType.Power}."));
}
ctx.Output.WriteLine(
FuelCalculator.AnnualPowerUsage(tariff, monthlyBudget).GetValueOrDefault().Value);
break;
default:
return(Commands.Error($"Unsupported fuel type : {fuelType}"));
}
return(Commands.Ok());
});
}