1. Database

package p01_Database;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import javax.naming.OperationNotSupportedException;

public class DatabaseTest {
    public Database database;
    private static final Integer[] NUMBERS = {7, 45, 34, 12, 98, 23};

    @Before
    public void prepareDatabase() throws OperationNotSupportedException {
       database = new Database(NUMBERS);
    }

    //1. конструктор
    //1.1. дали създава правилен обект
    @Test
    public void testConstructorHasCreateValidObject () {
        //проверка на елементите -> елементите = зададените
        Integer[] elements = database.getElements();
        //СРАВНЯВАМЕ МАСИВИТЕ
        Assert.assertArrayEquals("Arrays are not the same!", elements, NUMBERS);

        //брой елементите
        Assert.assertEquals("Count of elements is incorrect!", elements.length, NUMBERS.length);
        // стойностите на елементите
        for (int index = 0; index < elements.length; index++) {
            Assert.assertEquals("Arrays are not the same!",elements[index], NUMBERS[index]);
        }
    }
    //1.2. елементите > 16
    @Test(expected = OperationNotSupportedException.class)
    public void testConstructorThrowWhenMoreThanSixteenElements () throws OperationNotSupportedException {
        Integer[] numbers = new Integer[17]; //масив със 17 елемента
        new Database(numbers);
    }
    //1.3. елементите < 1
    @Test(expected = OperationNotSupportedException.class)
    public void testConstructorThrowWhenLessThanOneElement () throws OperationNotSupportedException {
        Integer[] numbers = new Integer[0];
        new Database(numbers);
    }

    //2. add
    //2.1. успешно добавяме елемент
    @Test
    public void testAddShouldAddElement() throws OperationNotSupportedException {
        //{7, 45, 34, 12, 98, 23} -> 6 елемента
        database.add(67);
        //{7, 45, 34, 12, 98, 23, 67} -> 7 елемента
        Integer[] elements = database.getElements();
        Assert.assertEquals("Invalid add operation!", elements.length, NUMBERS.length + 1);
        Assert.assertEquals(elements[elements.length - 1], Integer.valueOf(67));
    }
    //2.2. добавяне на null
    @Test (expected = OperationNotSupportedException.class)
    public void testAddShouldThrowNullParam() throws OperationNotSupportedException {
        database.add(null);
    }

    //3. remove
    //3.1. успешно премахване на елемент
    @Test
    public void testRemoveLastElement () throws OperationNotSupportedException {
        //{7, 45, 34, 12, 98, 23}
        database.remove();
        //{7, 45, 34, 12, 98}
        Integer[] elements = database.getElements();
        Assert.assertEquals(elements.length, NUMBERS.length - 1);
        Assert.assertEquals(elements[elements.length - 1], Integer.valueOf(98));
    }

    //3.2. премахване на елемент от празна database (elements = [])
    @Test(expected = OperationNotSupportedException.class)
    public void testRemoveThrowEmptyDatabase () throws OperationNotSupportedException {
        //{7, 45, 34, 12, 98, 23}
        //премахваме всички елементи
        for (int i = 0; i < NUMBERS.length ; i++) {
            database.remove();
        }
        //празна database - 0 елемента
        database.remove();
    }

}