public void GenerateAmSchedule_ShouldAccrueInterestFromStartDate(
int loanLength
)
{
//Assemble
var interestStartDate = new LocalDate(2001, 1, 1);
var paymentStartDate = new DateTime(2001 + loanLength, 1, 1);
var loan = GetTestLoan(
amount: 1000,
interestRate: 0.5m,
interestAccrualStartDate:
interestStartDate.ToDateTimeUnspecified(),
maturityDate: new DateTime(2001 + loanLength + 1, 1, 1)
);;
var yearlyInterest = loan.Amount * loan.InterestRate;
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: paymentStartDate,
paymentFrequency: PaymentFrequency.Annual,
startDate: paymentStartDate
)
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual[0].Interest.Should().Be(yearlyInterest * loanLength);
}
public void GenerateAmSchedule_PaymentTypeIsBullet_ShouldPayOffEntireLoan()
{
var loanAmount = 10000;
var loan = GetTestLoan(
amount: loanAmount,
interestRate: 0.1m,
interestAccrualStartDate: new DateTime(2001, 1, 1)
);
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
paymentFrequency: PaymentFrequency.Bullet,
paymentType: PaymentType.Bullet,
startDate: new DateTime(2001, 2, 1)
)
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = new DateTime(2001, 2, 1),
Interest = 84.93151m,
Principal = loanAmount,
RemainingBalance = 0
},
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_MultiplePaymentSchedules_ShouldOrderByDate()
{
//Assemble
var annualStartDate = new LocalDate(2001, 1, 1);
var semiAnnualStartDate = new LocalDate(2001, 3, 1);
var expected = new List <DateTime>
{
annualStartDate.ToDateTimeUnspecified(),
semiAnnualStartDate.ToDateTimeUnspecified(),
semiAnnualStartDate.PlusMonths(6).ToDateTimeUnspecified(),
annualStartDate.PlusYears(1).ToDateTimeUnspecified(),
semiAnnualStartDate.PlusYears(1).ToDateTimeUnspecified(),
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
GetTestLoan(maturityDate: new DateTime(2002, 4, 1)),
new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate:
annualStartDate.PlusYears(1).ToDateTimeUnspecified(),
paymentFrequency: PaymentFrequency.Annual,
startDate: annualStartDate.ToDateTimeUnspecified()
),
GetTestPaymentSchedule(
endDate: semiAnnualStartDate
.PlusYears(1)
.ToDateTimeUnspecified(),
paymentFrequency: PaymentFrequency.SemiAnnual,
startDate: semiAnnualStartDate.ToDateTimeUnspecified()
)
}
);
//Assert
actual.Select(x => x.Date).Should().Equal(expected);
}
private static void RunFrequencyTest(
List <DateTime> expected,
LocalDate endDate,
PaymentFrequency frequency
)
{
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
GetTestLoan(
amount: 1000,
maturityDate: endDate.ToDateTimeUnspecified()
),
new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: endDate.ToDateTimeUnspecified(),
paymentFrequency: frequency
)
}
);
//Assert
actual.Select(x => x.Date).Should().Equal(expected);
}
public Handler(AmortizationCalculator amortizationCalculator)
{
_amortizationCalculator = amortizationCalculator;
}
public void GenerateAmSchedule_ScheduleListContainsBulletPayment_AllPaymentsAtAndAfterBulletDateShouldBeRemoved()
{
var loanStartDate = new LocalDate(2001, 1, 1);
var loan = GetTestLoan(
amount: 3000,
interestAccrualStartDate: loanStartDate.ToDateTimeUnspecified(),
interestRate: 0.1m
);
var paymentSchedules = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate:
loanStartDate.PlusMonths(5).ToDateTimeUnspecified(),
paymentFrequency: PaymentFrequency.Monthly,
paymentAmount: 100,
paymentType: PaymentType.LevelPayment,
startDate:
loanStartDate.PlusMonths(1).ToDateTimeUnspecified()
),
GetTestPaymentSchedule(
paymentAmount: 0.1m,
paymentType: PaymentType.Bullet,
startDate:
loanStartDate.PlusMonths(2).ToDateTimeUnspecified()
),
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = loanStartDate.PlusMonths(1).ToDateTimeUnspecified(),
Interest = 25.47945m,
Principal = 74.52055m,
RemainingBalance = 2925.47945m,
},
new AmortizationScheduleItem
{
Date = loanStartDate.PlusMonths(2).ToDateTimeUnspecified(),
Interest = 22.44203m,
Principal = 2925.47945m,
RemainingBalance = 0m,
},
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedules
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_MultiplePaymentSchedulesProvided_ShouldCalculatePaymentsCorrectly()
{
//Assemble
var loanStartDate = new LocalDate(2001, 1, 1);
var percentagePaymentsStartDate =
loanStartDate.PlusMonths(1).PlusDays(15);
var loan = GetTestLoan(
amount: 3000,
interestAccrualStartDate: loanStartDate.ToDateTimeUnspecified(),
interestRate: 0.1m,
maturityDate: new DateTime(2001, 5, 1)
);
var paymentSchedules = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate:
loanStartDate.PlusMonths(2).ToDateTimeUnspecified(),
paymentFrequency: PaymentFrequency.Monthly,
paymentAmount: 100,
paymentType: PaymentType.LevelPayment,
startDate:
loanStartDate.PlusMonths(1).ToDateTimeUnspecified()
),
GetTestPaymentSchedule(
endDate: percentagePaymentsStartDate
.PlusMonths(1)
.ToDateTimeUnspecified(),
paymentFrequency: PaymentFrequency.Monthly,
paymentAmount: 0.1m,
paymentType: PaymentType.PrincipalPercentage,
startDate:
percentagePaymentsStartDate.ToDateTimeUnspecified()
),
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = loanStartDate.PlusMonths(1).ToDateTimeUnspecified(),
Interest = 25.47945m,
Principal = 74.52055m,
RemainingBalance = 2925.47945m,
},
new AmortizationScheduleItem
{
Date = percentagePaymentsStartDate.ToDateTimeUnspecified(),
Interest = 12.02252m,
Principal = 292.54795m,
RemainingBalance = 2632.93151m,
},
new AmortizationScheduleItem
{
Date = loanStartDate.PlusMonths(2).ToDateTimeUnspecified(),
Interest = 9.37756m,
Principal = 90.62244m,
RemainingBalance = 2542.30907m,
},
new AmortizationScheduleItem
{
Date = percentagePaymentsStartDate
.PlusMonths(1)
.ToDateTimeUnspecified(),
Interest = 10.44785m,
Principal = 254.23091m,
RemainingBalance = 2288.07816m,
},
//Automatic bullet payment
new AmortizationScheduleItem
{
Date = new DateTime(2001, 5, 1),
Interest = 28.83605m,
Principal = 2288.07816m,
RemainingBalance = 0m,
},
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedules
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_PaymentTypeIsPrincipalOnly_ShouldGenerateAmSchedule()
{
//Assemble
var levelPrincipalAmount = 300;
var numberOfPayments = 3;
var loan = GetTestLoan(
amount: levelPrincipalAmount * numberOfPayments,
interestRate: 0m,
maturityDate: new DateTime(2001, 5, 1)
);
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: new DateTime(2001, 4, 1),
paymentAmount: levelPrincipalAmount,
paymentFrequency: PaymentFrequency.Monthly,
paymentType: PaymentType.PrincipalOnly,
startDate: new DateTime(2001, 2, 1)
)
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = new DateTime(2001, 2, 1),
Interest = 0,
Principal = levelPrincipalAmount,
RemainingBalance = 600
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 3, 1),
Interest = 0,
Principal = levelPrincipalAmount,
RemainingBalance = 300
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 4, 1),
Interest = 0,
Principal = levelPrincipalAmount,
RemainingBalance = 0
},
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_PaymentTypeIsPrincipalPercentage_ShouldGenerateAmSchedule()
{
//Assemble
var loan = GetTestLoan(
amount: 1000,
interestRate: 0.1m,
maturityDate: new DateTime(2001, 5, 1)
);
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: new DateTime(2001, 4, 1),
paymentAmount: 0.2m,
paymentFrequency: PaymentFrequency.Monthly,
paymentType: PaymentType.PrincipalPercentage,
startDate: new DateTime(2001, 2, 1)
)
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = new DateTime(2001, 2, 1),
Interest = 8.49315m,
Principal = 200,
RemainingBalance = 800
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 3, 1),
Interest = 6.13699m,
Principal = 160,
RemainingBalance = 640
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 4, 1),
Interest = 5.43562m,
Principal = 128,
RemainingBalance = 512
},
//Automatic bullet payment
new AmortizationScheduleItem
{
Date = new DateTime(2001, 5, 1),
Interest = 4.20822m,
Principal = 512,
RemainingBalance = 0
}
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_LevelPaymentIsLessThanInterest_ShouldPayAsMuchInterestAsPossible()
{
//Assemble
var loan = GetTestLoan(
amount: 1000000,
interestRate: 0.5m,
maturityDate: new DateTime(2001, 5, 1)
);
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: new DateTime(2001, 4, 1),
paymentAmount: 500m,
paymentFrequency: PaymentFrequency.Monthly,
paymentType: PaymentType.LevelPayment,
startDate: new DateTime(2001, 2, 1)
)
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = new DateTime(2001, 2, 1),
Interest = 500,
Principal = 0,
RemainingBalance = 1000000
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 3, 1),
Interest = 500,
Principal = 0,
RemainingBalance = 1000000
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 4, 1),
Interest = 500,
Principal = 0,
RemainingBalance = 1000000
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 5, 1),
Interest = 162883.56164m,
Principal = 1000000,
RemainingBalance = 0m
},
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_PaymentTypeIsLevelPayment_ShouldGenerateAmSchedule()
{
//Assemble
var loan = GetTestLoan(
amount: 1000,
interestRate: 0.1m
);
var paymentSchedule = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: new DateTime(2001, 4, 1),
paymentAmount: 338.9m,
paymentFrequency: PaymentFrequency.Monthly,
paymentType: PaymentType.LevelPayment,
startDate: new DateTime(2001, 2, 1)
)
};
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = new DateTime(2001, 2, 1),
Interest = 8.49315m,
Principal = 330.40685m,
RemainingBalance = 669.59315m
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 3, 1),
Interest = 5.13660m,
Principal = 333.76340m,
RemainingBalance = 335.82976m
},
new AmortizationScheduleItem
{
Date = new DateTime(2001, 4, 1),
Interest = 2.85225m,
Principal = 335.82976m,
RemainingBalance = 0m
}
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedule
);
//Assert
actual
.Select(x => new AmortizationScheduleItem
{
Date = x.Date,
Interest = TestUtils.RoundDecimal(x.Interest),
Principal = TestUtils.RoundDecimal(x.Principal),
RemainingBalance =
TestUtils.RoundDecimal(x.RemainingBalance),
})
.Should()
.BeEquivalentTo(expected, x => x.Excluding(x => x.Schedule));
}
public void GenerateAmSchedule_PaymentTypeIsInterestOnly_ShouldGenerateAmSchedule()
{
//Assemble
var startDate = new LocalDate(2001, 1, 1);
var loan = GetTestLoan(
accrualBasis: AccrualBasis.Thirty360,
amount: 1000,
interestRate: 0.5m,
interestAccrualStartDate: startDate.ToDateTimeUnspecified()
);
var monthlyDate = startDate.PlusMonths(1).ToDateTimeUnspecified();
var quarterlyDate = startDate.PlusMonths(3).ToDateTimeUnspecified();
var semiDate = startDate.PlusMonths(6).ToDateTimeUnspecified();
var annualDate = startDate.PlusYears(1).ToDateTimeUnspecified();
var expected = new List <AmortizationScheduleItem>
{
new AmortizationScheduleItem
{
Date = monthlyDate,
//1 month of interest
Interest = loan.Amount * loan.InterestRate / 12
},
new AmortizationScheduleItem
{
Date = quarterlyDate,
//2 months of interest
Interest = loan.Amount * loan.InterestRate / 6
},
new AmortizationScheduleItem
{
Date = semiDate,
//3 months of interest
Interest = loan.Amount * loan.InterestRate / 4
},
new AmortizationScheduleItem
{
Date = annualDate,
//6 months of interest
Interest = loan.Amount * loan.InterestRate / 2
}
};
var paymentSchedules = new List <PaymentSchedule>
{
GetTestPaymentSchedule(
endDate: monthlyDate,
paymentFrequency: PaymentFrequency.Monthly,
startDate: monthlyDate
),
GetTestPaymentSchedule(
endDate: quarterlyDate,
paymentFrequency: PaymentFrequency.Quarterly,
startDate: quarterlyDate
),
GetTestPaymentSchedule(
endDate: semiDate,
paymentFrequency: PaymentFrequency.SemiAnnual,
startDate: semiDate
),
GetTestPaymentSchedule(
endDate: annualDate,
paymentFrequency: PaymentFrequency.Annual,
startDate: annualDate
)
};
//Act
var actual = AmortizationCalculator.GenerateAmortizationSchedule(
loan,
paymentSchedules
);
//Assert
actual
.Select(x => x.Date)
.Should()
.Equal(expected.Select(x => x.Date));
actual
.Select(x => TestUtils.RoundDecimal(x.Interest))
.Should()
.Equal(expected.Select(x => TestUtils.RoundDecimal(x.Interest)));
}