IdObjectListTest.java

package de.saring.util.data;

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

import java.util.ArrayList;

import static org.junit.Assert.*;

/**
 * Unit tests of class IdObjectList.
 *
 * @author Stefan Saring
 */
public class IdObjectListTest {

    /**
     * The instance to test.
     */
    private IdObjectList<NameObject> list;

    @Before
    public void setUp() {

        // create a new list with some content
        list = new IdObjectList<>();
        list.set(new NameObject(1, "one"));
        list.set(new NameObject(2, "two"));
        list.set(new NameObject(3, "three"));
    }

    /**
     * Test of getByID method, of class IdObjectList.
     */
    @Test
    public void getByID() {
        assertNull(list.getByID(0));
        assertNull(list.getByID(1000));
        assertEquals("one", list.getByID(1).getName());
        assertEquals("three", list.getByID(3).getName());
    }

    /**
     * Test of getAt method, of class IdObjectList.
     */
    @Test
    public void getAt() {
        assertEquals("one", list.getAt(0).getName());
        assertEquals("three", list.getAt(2).getName());

        try {
            list.getAt(3);
            fail("Must fail, index is not valid...");
        } catch (IndexOutOfBoundsException e) {
        }
    }

    /**
     * Test of indexOf method, of class IdObjectList.
     */
    @Test
    public void indexOf() {
        assertEquals(1, list.indexOf(new NameObject(2, "two")));
    }

    /**
     * Test of contains method, of class IdObjectList.
     */
    @Test
    public void contains() {
        assertTrue(list.contains(new NameObject(2, "two")));
        assertFalse(list.contains(new NameObject(4, "four")));
    }

    /**
     * Test of set method set() of class IdObjectList.
     */
    @Test
    public void set() {

        // this should add an element to list
        list.set(new NameObject(4, "four"));
        assertEquals(4, list.size());
        assertEquals("four", list.getAt(3).getName());

        // this should replace a list-element
        list.set(new NameObject(2, "zwei"));
        assertEquals(4, list.size());
        assertEquals("zwei", list.getByID(2).getName());
    }

    /**
     * Test of set method set() of class IdObjectList: must fail on null.
     */
    @Test(expected = NullPointerException.class)
    public void setNull() {
        list.set(null);
    }

    /**
     * Test of set method set() of class IdObjectList: must fail when ID = 0.
     */
    @Test(expected = IllegalArgumentException.class)
    public void setIdZero() {
        list.set(new NameObject(0, "Null"));
    }

    /**
     * Test of method clearAndAddAll(). The previous list content must be removed, the
     * list must contain only the new entries.
     */
    @Test
    public void clearAndAddAll() {

        ArrayList<NameObject> tempEntries = new ArrayList<>();
        tempEntries.add(new NameObject(5, "five"));
        tempEntries.add(new NameObject(6, "six"));
        list.clearAndAddAll(tempEntries);

        assertEquals(2, list.size());
        assertEquals("five", list.getAt(0).getName());
        assertEquals("six", list.getAt(1).getName());
    }

    /**
     * Test of method clearAndAddAll(). Must fail when null is passed.
     */
    @Test(expected = NullPointerException.class)
    public void clearAndAddAllNull() {
        list.clearAndAddAll(null);
    }

    /**
     * Test of method clearAndAddAll(). Must fail when an entry contain an invalid ID.
     */
    @Test(expected = IllegalArgumentException.class)
    public void clearAndAddAllInvalidId() {

        ArrayList<NameObject> tempEntries = new ArrayList<>();
        tempEntries.add(new NameObject(5, "five"));
        tempEntries.add(new NameObject(-6, "minus six"));
        list.clearAndAddAll(tempEntries);
    }

    /**
     * Test of removeByID method, of class IdObjectList.
     */
    @Test
    public void removeByID() {

        // this delete must work
        assertTrue(list.removeByID(3));
        assertEquals(2, list.size());
        assertNull(list.getByID(3));

        // this delete can't work
        assertFalse(list.removeByID(3));
        assertEquals(2, list.size());
    }

    /**
     * Test of getNewID method, of class IdObjectList.
     */
    @Test
    public void getNewID() {

        // ID's 1-3 in use => next needs to be 4
        assertEquals(list.getNewID(), 4);

        // add ID's 4 and 6 to list => next needs to be 5
        list.set(new NameObject(4, "four"));
        list.set(new NameObject(6, "six"));
        assertEquals(5, list.getNewID());

        // remove ID 2 from list => next needs to be 2
        list.removeByID(2);
        assertEquals(2, list.getNewID());
    }

    /**
     * Subclass of abstract class IdObject for testing.
     */
    static class NameObject extends IdObject {

        private String name;

        public NameObject(int id, String name) {
            super(id);
            this.name = name;
        }

        public String getName() {
            return name;
        }
    }
}