тест №3

import core.Data;

import interfaces.Entity;
import interfaces.Repository;
import model.BaseEntity;
import model.Invoice;
import model.StoreClient;
import model.User;
import org.junit.Before;
import org.junit.Test;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;

import static org.junit.Assert.*;

public class DataTest3 {
    private Repository data;
    private int parentId;
    private Entity savedEntity;
    private int[] statusesCount;

    @Before
    public void setUp() throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        this.data = new Data();
        Constructor<?>[] constructors = {getConstructor(Invoice.class), getConstructor(StoreClient.class), getConstructor(User.class)};
        Random random = new Random();
        BaseEntity.Status[] statuses = BaseEntity.Status.values();
        this.statusesCount = new int[statuses.length];
        List<Integer> parentIds = new ArrayList<>();
        parentIds.add(0);
        for (int i = 0; i < 25; i++) {
            Constructor<?> constructor = constructors[random.nextInt(constructors.length)];
            int nextInt = random.nextInt(i + 1);
            Entity entity = (Entity) constructor.newInstance(i, parentIds.get(nextInt));
            parentIds.add(i);
            if (entity.getId() == 13) {
                this.parentId = entity.getParentId();
                savedEntity = entity;
            }
            int enumIndex = random.nextInt(statuses.length);
            entity.setStatus(statuses[enumIndex]);
            statusesCount[enumIndex]++;
            this.data.add(entity);
        }
    }

    private Constructor<?> getConstructor(Class<?> clazz) throws NoSuchMethodException {
        return clazz.getDeclaredConstructor(int.class, int.class);
    }

    @Test(expected = IllegalStateException.class)
    public void getIdWhenNull() {
        Repository repository = new Data();
        repository.peekMostRecent();
    }
}