Date Util to add working days for given date

DateUtil.java

import lombok.NoArgsConstructor;

import java.time.DayOfWeek;
import java.time.LocalDate;

import static java.time.DayOfWeek.SATURDAY;
import static java.time.DayOfWeek.SUNDAY;
import static lombok.AccessLevel.PRIVATE;

@NoArgsConstructor(access = PRIVATE)
public class DateUtil {

    public static final int ONE_DAY = 1;

    public static LocalDate getNextWorkingDay(LocalDate date) {
        if (isWeekEnd(date)) {
            return getNextWorkingDay(date.plusDays(ONE_DAY));
        }
        return date;
    }

    public static LocalDate addWorkingDays(LocalDate startDate, int numberOfWorkingDays) {
        return getWorkingDays(startDate, numberOfWorkingDays).minusDays(ONE_DAY);
    }

    private static LocalDate getWorkingDays(LocalDate startDate, int numberOfWorkingDays) {
        if (numberOfWorkingDays < ONE_DAY) {
            return startDate.plusDays(ONE_DAY);
        }
        LocalDate tempDate = startDate;
        int daysAdded = 0;
        while (!isWeekEnd(tempDate)) {
            tempDate = tempDate.plusDays(ONE_DAY);
            daysAdded++;
            if (daysAdded == numberOfWorkingDays) {
                return tempDate;
            }
        }
        if (daysAdded <= numberOfWorkingDays) {
            tempDate = getWorkingDays(tempDate.plusDays(ONE_DAY), numberOfWorkingDays - daysAdded);
        }
        return tempDate;
    }

    private static boolean isWeekEnd(LocalDate date) {
        DayOfWeek dayOfWeek = date.getDayOfWeek();
        return dayOfWeek == SATURDAY || dayOfWeek == SUNDAY;
    }
}

DateUtilTest.java

import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

import java.time.LocalDate;
import java.util.stream.Stream;

import static com.generali.dol.util.DateUtil.addWorkingDays;
import static com.generali.dol.util.DateUtil.getNextWorkingDay;
import static java.time.Month.FEBRUARY;
import static java.time.Month.MARCH;
import static org.junit.jupiter.api.Assertions.assertEquals;

class DateUtilTest {

    public static final int NUMBER_OF_WORKING_DAYS = 10;

    @Test
    void shouldAddTenWorkingDaysFromMidWeek() {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, 11);
        final LocalDate expectedEndDate = LocalDate.of(2021, FEBRUARY, 24);

        assertEquals(expectedEndDate, addWorkingDays(actualStartDate, NUMBER_OF_WORKING_DAYS));
    }

    @Test
    void shouldAddTenWorkingDaysIfTodayStartFromWeekend() {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, 27);
        final LocalDate expectedEndDate = LocalDate.of(2021, MARCH, 12);

        assertEquals(expectedEndDate, addWorkingDays(actualStartDate, NUMBER_OF_WORKING_DAYS));
    }

    @Test
    void shouldAddTenWorkingDaysIfTodayIsFriday() {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, 12);
        final LocalDate expectedEndDate = LocalDate.of(2021, FEBRUARY, 25);

        assertEquals(expectedEndDate, addWorkingDays(actualStartDate, NUMBER_OF_WORKING_DAYS));
    }

    @Test
    void shouldReturnSameDayIfTodayIsFridayAndWorkingDayRequiredIsOne() {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, 12);
        final LocalDate expectedEndDate = LocalDate.of(2021, FEBRUARY, 12);

        assertEquals(expectedEndDate, addWorkingDays(actualStartDate, 1));
    }

    @Test
    void shouldReturnSameDayIfTodayIsFridayAndWorkingDayRequiredIsZero() {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, 12);
        final LocalDate expectedEndDate = LocalDate.of(2021, FEBRUARY, 12);

        assertEquals(expectedEndDate, addWorkingDays(actualStartDate, 0));
    }

    @ParameterizedTest
    @MethodSource("generateDatesForWorkingDay")
    void shouldReturnNextOrSameWorkingDayDependingOnWeekend(int startDayDate, int endDayDate) {
        final LocalDate actualStartDate = LocalDate.of(2021, FEBRUARY, startDayDate);
        final LocalDate expectedEndDate = LocalDate.of(2021, FEBRUARY, endDayDate);

        assertEquals(expectedEndDate, getNextWorkingDay(actualStartDate));
    }

    private static Stream<Arguments> generateDatesForWorkingDay() {
        return Stream.of(
          Arguments.of(12, 12),
          Arguments.of(13, 15),
          Arguments.of(14, 15)
        );
    }
}