public void ServiceTaxTest()
{
var serviceTax = 12.5;
Func <double, double> lambda = SuperMarket.CalculateServiceTax(serviceTax);
var totalWithServiceTax = lambda(1500);
Assert.That(totalWithServiceTax, Is.EqualTo(1687.5));
}
public void GivenALisOfItemHolds_WhenCalculateTotalCostCalled_ThenReturnsTotalCostWithSeviceTaxApplied()
{
// Arrange
var items = new List <ItemHolder>()
{
new ItemHolder("1", 10, 50),
new ItemHolder("2", 1, 500),
new ItemHolder("3", 5, 100)
};
Func <List <ItemHolder>, double> totalCalculator = SuperMarket.CalculateTotalCost;
var costCalculator = totalCalculator.AndThen(SuperMarket.CalculateServiceTax(12.5));
// Act
var totalCost = costCalculator(items);
// Assert
Assert.That(totalCost, Is.EqualTo(1687.5));
}