public void TestSimpleAddition()
{
Money five = Money.Dollar(5);
IBankExpression result = five.Plus(five);
Sum sum = (Sum)result;
Assert.Equal(five, sum.Augend);
}
public void TestMixedAddition()
{
IBankExpression fiveBucks = Money.Dollar(5);
IBankExpression tenFrancs = Money.Franc(10);
var bank = new Bank();
bank.AddRate("CHF", "USD", 2);
var result = bank.Reduce(fiveBucks.Plus(tenFrancs), "USD");
Assert.Equal(Money.Dollar(10), result);
}
public void TestSumTimesMoney()
{
IBankExpression fiveBucks = Money.Dollar(5);
IBankExpression tenFrancs = Money.Franc(10);
var bank = new Bank();
bank.AddRate("CHF", "USD", 2);
IBankExpression sum = new Sum(fiveBucks, tenFrancs).Times(2);
var result = bank.Reduce(sum, "USD");
Assert.Equal(Money.Dollar(20), result);
}
public Sum(IBankExpression augend, IBankExpression addend)
{
Augend = augend;
Addend = addend;
}
public IBankExpression Plus(IBankExpression addend)
{
return(new Sum(this, addend));
}
public Money Reduce(IBankExpression source, string to)
{
return(source.Reduce(this, to));
}
public void TestPlusSameCurrencyReturnsMoney()
{
IBankExpression sum = Money.Dollar(1).Plus(Money.Dollar(1));
Assert.True(sum is Sum);
}
