import org.junit.jupiter.api.Assertions import org.junit.jupiter.api.Test import java.util.* class AgeCalculation() { fun getAge(dob: Calendar): Int { val today = Calendar.getInstance() if (dob.timeInMillis > today.timeInMillis) throw IllegalAccessException() val years = today.get(Calendar.YEAR) - dob.get(Calendar.YEAR) return if (dob.get(Calendar.DAY_OF_YEAR) > today.get(Calendar.DAY_OF_YEAR)) { years - 1 } else { years } } } class AgeCalculationTest() { @Test fun testForException() { val date = Calendar.getInstance() date.add(Calendar.DAY_OF_YEAR, 10) Assertions.assertThrows(java.lang.IllegalAccessException::class.java) { AgeCalculation().getAge(date) } } }