public void SubtractYears_WhenSubtractingYears_ReturnNewInstance()
{
// Arrange
var date = new DuodecimDate(2018, 6);
// Act
var newDate = date.SubtractYears(1);
// Assert
Assert.False(Equals(date, newDate));
}
public void SubtractYears_WhenSubtractingNegativeYears_ThrowArgumentOutOfRangeException()
{
// Arrange
const int yearsToSubtract = -1;
var date = new DuodecimDate(2018, 6);
// Act
var exception = Record.Exception(() => date.SubtractYears(yearsToSubtract));
// Assert
exception.Verify <ArgumentOutOfRangeException>(string.Format(ExpectedYearOrMonthIsNegativeExceptionMessage,
"years"));
}
public void SubtractYears_WhenSubtractingYears_YearsSubtracted()
{
// Arrange
const int startYear = 2018;
const int yearsToSubtract = 13;
const int expectedYear = startYear - yearsToSubtract;
var date = new DuodecimDate(startYear, 6);
// Act
var newDate = date.SubtractYears(yearsToSubtract);
// Assert
Assert.Equal(expectedYear, newDate.Year);
}
public void SubtractYears_WhenSubtractingYearsSoTheResultYieldsAnInvalidYear_ThrowInvalidDuodecimDateException()
{
// Arrange
const int startYear = 2018;
const int yearsToSubtract = startYear;
const int expectedErrorMessageYear = startYear - yearsToSubtract;
const int month = 6;
var date = new DuodecimDate(startYear, 6);
// Act
var exception = Record.Exception(() => date.SubtractYears(yearsToSubtract));
// Assert
exception.Verify <InvalidDuodecimDateException>(string.Format(ExpectedInvalidDuodecimDateExceptionMessage,
expectedErrorMessageYear, month));
}