public CostCommand(ITariffSource source)
{
Spec = CommandSpec.Named(
"cost",
new[] { "POWER_USAGE_KWH", "GAS_USAGE_KWH" },
ctx =>
{
// model 0's explicitly as no fuel supply for that type
var p = ctx.GetRequiredDecimal("POWER_USAGE_KWH");
var powerKwh = p == 0 ? new Kwh <Power>?() : new Kwh <Power>(p);
var g = ctx.GetRequiredDecimal("GAS_USAGE_KWH");
var gasKwh = g == 0 ? new Kwh <Gas>?() : new Kwh <Gas>(g);
// calculate the costs and output
foreach (var line in FuelCalculator
.CostsPerTariff(source.GetAll(), powerKwh, gasKwh)
.Select(cost => $"{cost.Tariff.Name} {cost.Total.PostTax:F2}"))
{
ctx.Output.WriteLine(line);
}
return(Commands.Ok());
});
}
public void CostsPerTariff_PowerNotInTariff_ReturnsCosts()
{
// Arrange
var tariff = new Tariff("test", null, 3m, 4m);
// Act
var actual = FuelCalculator.CostsPerTariff(new[] { tariff }, null, new Kwh <Gas>(2000)).ToList();
// Assert
actual.Should().HaveCount(1);
var actualCost = actual.First();
actualCost.Tariff.Should().Be(tariff);
actualCost.Total.PostTax.Should().Be(((4 * 12) + (2000 * 3)) * 1.05M);
}
public void CostsPerTariff_GasNotInTariff_TariffIgnored()
{
// Arrange
var tariff = new Tariff("test", 2m, 3m, 4m);
var tariff2 = new Tariff("test2", 4m, null, 8m);
// Act
var actual = FuelCalculator.CostsPerTariff(new[] { tariff, tariff2 }, new Kwh <Power>(1000), new Kwh <Gas>(2000)).ToList();
// Assert
actual.Should().HaveCount(1);
var actualCost = actual.First();
actualCost.Tariff.Should().Be(tariff);
actualCost.Total.PostTax.Should().Be(((4 * 12) + (1000 * 2) + (4 * 12) + (2000 * 3)) * 1.05M);
}
public void CostsPerTariff_PowerUsageNotSupplied_ReturnsCostsForValidTariffs()
{
// Arrange
var tariff1 = new Tariff("test1", 2m, null, 4m);
var tariff2 = new Tariff("test2", 4m, 6m, 8m);
// Act
var actual = FuelCalculator.CostsPerTariff(new[] { tariff1, tariff2 }, null, new Kwh <Gas>(2000)).ToList();
// Assert
actual.Should().HaveCount(1);
var actualCost = actual.First();
actualCost.Tariff.Should().Be(tariff2);
actualCost.Total.PostTax.Should().Be(((8 * 12) + (2000 * 6)) * 1.05M);
}
public void CostsPerTariff_AllFuelTypesSupported_ReturnsCostsInOrder()
{
// Arrange
var tariff1 = new Tariff("test1", 2m, 3m, 4m);
var tariff2 = new Tariff("test2", 4m, 6m, 8m);
// Act
var actual = FuelCalculator.CostsPerTariff(new[] { tariff1, tariff2 }, new Kwh <Power>(1000), new Kwh <Gas>(2000)).ToList();
// Assert
actual.Should().HaveCount(2);
var actualCost = actual.First();
actualCost.Tariff.Should().Be(tariff1);
actualCost.Total.PostTax.Should().Be(((4 * 12) + (1000 * 2) + (4 * 12) + (2000 * 3)) * 1.05M);
actual.ElementAt(1).Tariff.Should().Be(tariff2);
}
