@Test
public void testGetActualPaymentWithNullRegularPayment() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setRegularPayment(null);
MonetaryAmount periodicPayment = AmortizationCalculator.getPeriodicPayment(amAttrs);
assertNotNull("Regular payment computed when initialized as null", periodicPayment);
}
@Test
public void testGetPaymentsAmortizedWithOverPayment() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(ofUSD(10000));
amAttrs.setInterestRateAsPercent(3.);
amAttrs.setInterestOnly(false);
amAttrs.setRegularPayment(ofUSD(400));
amAttrs.setPaymentFrequency(TimePeriod.SemiMonthly.getPeriodsPerYear());
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAmortizationPeriodInMonths(24);
amAttrs.setCompoundingPeriodsPerYear(2);
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
assertEquals(
"Amortized payment count",
amAttrs.getPaymentFrequency() * termInMonths / 12,
schedule.size());
MonetaryAmount interestTotal =
schedule.stream().map(payment -> payment.getInterest()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Interest total", ofUSD(164.81), interestTotal);
}
@Test
public void testGetPaymentsAmortizedFully() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
MonetaryAmount loanAmount = ofUSD(10000);
amAttrs.setLoanAmount(loanAmount);
amAttrs.setInterestRateAsPercent(7.);
amAttrs.setInterestOnly(false);
amAttrs.setPaymentFrequency(TimePeriod.Monthly.getPeriodsPerYear());
int termInMonths = 12;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAmortizationPeriodInMonths(12);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setRegularPayment(AmortizationCalculator.getPeriodicPayment(amAttrs));
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
MonetaryAmount interestTotal =
schedule.stream().map(payment -> payment.getInterest()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Interest total", ofUSD(377.67), interestTotal);
MonetaryAmount principalTotal =
schedule.stream().map(payment -> payment.getPrincipal()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Principal fully paid", loanAmount, principalTotal);
}
@Test
public void testGenerateScheduleInterestOnlyArrayBounds() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(ofUSD(10000));
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setInterestOnly(true);
amAttrs.setPaymentFrequency(TimePeriod.Weekly.getPeriodsPerYear());
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAdjustmentDate(LocalDate.of(2016, Month.JANUARY, 1));
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
try {
schedule.get(-1);
fail("Interest only schedule should not allow negative payment number");
} catch (IndexOutOfBoundsException iobe) {
}
int expectedPayments =
(int) Math.ceil(amAttrs.getPaymentFrequency() * amAttrs.getTermInMonths() / 12.);
try {
schedule.get(expectedPayments);
fail("Interest only schedule should not allow payments beyond schedule bound");
} catch (IndexOutOfBoundsException iobe) {
}
schedule.get(expectedPayments - 1);
}
@Test
public void testGenerateScheduleInterestOnlyMonthly() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(ofUSD(10000));
amAttrs.setInterestRateAsPercent(10.);
amAttrs.setInterestOnly(true);
amAttrs.setPaymentFrequency(TimePeriod.Monthly.getPeriodsPerYear());
int termInMonths = 12;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAdjustmentDate(LocalDate.of(2016, Month.JANUARY, 1));
amAttrs.setRegularPayment(ofUSD(0));
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
assertEquals("Interest only schedule term in months", termInMonths, schedule.size());
MonetaryAmount expectedInterest = ofUSD(83.34);
MonetaryAmount expectedPrincipal = ofUSD(0);
LocalDate expectedDate = amAttrs.getAdjustmentDate();
int index = 0;
for (ScheduledPayment payment : schedule) {
expectedDate = expectedDate.plusMonths(1L);
assertEquals("Interest only schedule payment number", ++index, payment.getPaymentNumber());
assertEquals("Interest only schedule payment date", expectedDate, payment.getPaymentDate());
assertEquals(
"Interest only schedule payment interest", expectedInterest, payment.getInterest());
assertEquals(
"Interest only schedule payment principal", expectedPrincipal, payment.getPrincipal());
assertEquals(
"Interest only schedule payment total payment", expectedInterest, payment.getPayment());
assertEquals(
"Interest only schedule payment loan principal", ofUSD(10000), payment.getBalance());
}
}
@Test
public void testGetPeriodicPaymentInterestOnlyMonthly() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000);
amAttrs.setPaymentFrequency(12);
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setInterestOnly(true);
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
assertEquals("Monthly interest-only payment", USD500, result);
}
@Test
public void testGetPeriodicPaymentAmortizedMonthlyCompoundPeriod() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.multiply(2));
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setCompoundingPeriodsPerYear(12);
amAttrs.setPaymentFrequency(12);
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount expectedResult = ofUSD(1053.23);
assertEquals("Monthly amortized payment compounded monthly", expectedResult, result);
}
@Test
public void testPaymentDateWeekly() {
LocalDate scheduleStartDate = LocalDate.of(2015, Month.DECEMBER, 2);
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setAdjustmentDate(scheduleStartDate);
amAttrs.setPaymentFrequency(TimePeriod.Weekly.getPeriodsPerYear());
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
for (int i = 1; i <= (52 * 2); i++) {
String msg = String.format("Date for weekly payment %d", i);
assertEquals(msg, scheduleStartDate.plusWeeks(i), schedule.get(i - 1).getPaymentDate());
}
}
private void testPaymentDatesWithMonthlyIntervals(int periodsPerYear) {
LocalDate scheduleStartDate = LocalDate.of(2015, Month.DECEMBER, 2);
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setAdjustmentDate(scheduleStartDate);
amAttrs.setPaymentFrequency(periodsPerYear);
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
for (int i = 1; i <= termInMonths / (12 / periodsPerYear); i++) {
String msg = String.format("Date for payment %d when %d payments a year", i, periodsPerYear);
assertEquals(
msg,
scheduleStartDate.plusMonths(i * (12 / periodsPerYear)),
schedule.get(i - 1).getPaymentDate());
}
}
@Test
public void testGetPeriodicPaymentInterestOnlyMonthlyRoundsCeiling() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000);
amAttrs.setPaymentFrequency(12);
amAttrs.setInterestRateAsPercent(11.);
amAttrs.setInterestOnly(true);
MonetaryAmount expectedResult =
Monetary.getDefaultAmountFactory().setCurrency("USD").setNumber(458.34).create();
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
assertEquals(
"Monthly interest-only payment fractional penny, less than half a cent, rounds UP",
expectedResult,
result);
}
@Test
public void testGetPeriodInterest_InterestOnly() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000);
amAttrs.setPaymentFrequency(12);
amAttrs.setInterestRateAsPercent(11.);
amAttrs.setInterestOnly(true);
// MonetaryAmount expectedResult = Monetary.getDefaultAmountFactory()
// .setCurrency("USD")
// .setNumber(458.34)
// .create();
MonetaryAmount periodicPaymentResult = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount periodInterestRestult = AmortizationCalculator.getPeriodInterest(amAttrs);
assertEquals(
"Monthly interest-only payment should match interest computed for period.",
periodicPaymentResult,
periodInterestRestult);
}
@Test
public void testPaymentDateSemiMonthly() {
LocalDate scheduleStartDate = LocalDate.of(2015, Month.DECEMBER, 2);
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setAdjustmentDate(scheduleStartDate);
amAttrs.setPaymentFrequency(TimePeriod.SemiMonthly.getPeriodsPerYear());
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
int dayOfMonthPayment1 = scheduleStartDate.getDayOfMonth();
int dayOfMonthPayment2 = scheduleStartDate.plusDays(14).getDayOfMonth();
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
// First payment of month
for (int i = 1; i <= 48; i += 2) {
String msg = String.format("First date for semi-monthly payment %d", i);
assertEquals(
msg,
scheduleStartDate.plusMonths(i / 2).plusDays(14),
schedule.get(i - 1).getPaymentDate());
assertEquals(
"Semi-monthly common day of month",
dayOfMonthPayment2,
schedule.get(i - 1).getPaymentDate().getDayOfMonth());
}
// Second payment of month
for (int i = 2; i <= 48; i += 2) {
String msg = String.format("Second date for semi-monthly payment %d", i);
assertEquals(msg, scheduleStartDate.plusMonths(i / 2), schedule.get(i - 1).getPaymentDate());
assertEquals(
"Semi-monthly common day of month",
dayOfMonthPayment1,
schedule.get(i - 1).getPaymentDate().getDayOfMonth());
}
}
@Test
public void testGetPeriodicPaymentCompoundSemiPaymentSemiAnnually() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.divide(5));
amAttrs.setInterestRateAsPercent(10.);
amAttrs.setCompoundingPeriodsPerYear(TimePeriod.SemiAnnually.getPeriodsPerYear());
amAttrs.setAmortizationPeriodInMonths(12);
amAttrs.setPaymentFrequency(TimePeriod.SemiAnnually.getPeriodsPerYear());
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount expectedResult = ofUSD(5378.05);
assertEquals("Amortized, compounded semi-annual, payment semimonthly", expectedResult, result);
}
@Test
public void testGetPeriodInterest_Amortized() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.multiply(2));
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setPaymentFrequency(12);
List<ScheduledPayment> generatedSchedule = AmortizationCalculator.generateSchedule(amAttrs);
generatedSchedule
.stream()
.forEachOrdered(
p -> {
MonetaryAmount periodInterest = AmortizationCalculator.getPeriodInterest(amAttrs);
assertEquals(
"Monthly amortized payment interest matches peirod interest",
p.getInterest(),
periodInterest);
amAttrs.setLoanAmount(p.getBalance());
});
}
@Test
public void testGetPeriodicPaymentInterestOnlyTimePeriods() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000);
amAttrs.setInterestRateAsPercent(10.);
amAttrs.setInterestOnly(true);
amAttrs.setPaymentFrequency(52);
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount expectedResult = ofUSD(96.16);
assertEquals("Weekly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(26);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(192.31);
assertEquals("BiWeekly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(26);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(192.31);
assertEquals("BiWeekly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(12);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(416.67);
assertEquals("Monthly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(6);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(833.34);
assertEquals("BiMonthly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(4);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(1250);
assertEquals("Quarterly interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(2);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(2500);
assertEquals("Semiannual interest-only", expectedResult, result);
amAttrs.setPaymentFrequency(1);
result = AmortizationCalculator.getPeriodicPayment(amAttrs);
expectedResult = ofUSD(5000);
assertEquals("Annual interest-only", expectedResult, result);
}
private AmortizationAttributes generateAmortizationAttributesObjectTemplate() {
AmortizationAttributes amAttrs = new AmortizationAttributes();
amAttrs.setLoanAmount(USD50000);
amAttrs.setRegularPayment(USD50000.divide(100));
amAttrs.setStartDate(LocalDate.of(2015, Month.DECEMBER, 28));
amAttrs.setAdjustmentDate(LocalDate.of(2016, Month.JANUARY, 1));
amAttrs.setTermInMonths(24);
amAttrs.setInterestOnly(false);
amAttrs.setAmortizationPeriodInMonths(300);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setPaymentFrequency(12);
amAttrs.setInterestRateAsPercent(12.);
return amAttrs;
}