public void SimpleInterestCalculator_CalculateInterestGivesZeroNewPrincipal()
{
// Arrange
var startingPrincipal = 100.0;
var rate = 0.15;
var expected = 0.0;
var target = new SimpleInterestCalculator();
PrincipalInterestBalance result;
double actual;
// Act
result = target.CalculateInterest(startingPrincipal, rate, 1);
actual = result.Principal;
// Assert
Assert.AreEqual(expected, actual, 0.0000001);
}
