public void ShouldCalculateMonthlyPaymentWhenInputValid()
{
var monthlyPaymentAmount = MortgageInstallmentCalculator.CalculateMonthlyPayment(1000, 1, 12);
Assert.AreEqual(88.8487886783416d, monthlyPaymentAmount, 0.01d);
}
public void ShouldThrowInvalidInputExceptionOnNegativeInterestRate()
{
MortgageInstallmentCalculator.CalculateMonthlyPayment(20, 1, -12);
}
public void ShouldThrowInvalidInputExceptionOnNegativePrincipalAmount()
{
MortgageInstallmentCalculator.CalculateMonthlyPayment(20, -10, 14.5);
}
public void ShouldThrowInvalidInputExceptionOnNegativeTenure()
{
MortgageInstallmentCalculator.CalculateMonthlyPayment(-20, 1, 14.5);
}