LinkedListTest.java

import static org.junit.Assert.*;

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

import java.util.ArrayList;

/**
 * Linked List Tests
 * @author Chintan
 *
 */
public class LinkedListTest {
  private LinkedList<Integer> list;
	private Integer i, j, k;
	
	@Before
	public void setUp()
	{
		list = new LinkedList<Integer>();
		i = new Integer(5);
		j = new Integer(6);
		k = new Integer(7);
	}
	
	@Test
	public void testAdd() {
		list.add(i);
		// Test that a node has been added to the head
		assertTrue(list.getHead().getData().equals(i));
		
		// Test that the node points to it's self
		assertTrue(list.getHead().getNext().getData().equals(i));
		
		list.add(j);
		// Test that the head hasn't been changed
		assertTrue(list.getHead().getData().equals(i));
		
		// Test that the head points to our new node
		assertTrue(list.getHead().getNext().getData().equals(j));
		
		// Test that our new node points to the head
		assertTrue(list.getHead().getNext().getNext().getData().equals(i));
	}
	
	@Test
	public void testAddAll() {
		// Test adding an empty collection
		// Test adding a collection with two elements
		ArrayList<Integer> collection = new ArrayList<Integer>();
		collection.add(i);
		collection.add(j);
		
		list.addAll(collection);
		assertTrue(list.getHead().getData().equals(i));
		assertTrue(list.getHead().getNext().getData().equals(j));
		assertTrue(list.getHead().getNext().getNext().getData().equals(i));
		
		collection = new ArrayList<Integer>();
		list.addAll(collection);
		// Shouldn't change anything
		assertTrue(list.getHead().getData().equals(i));
		assertTrue(list.getHead().getNext().getData().equals(j));
		assertTrue(list.getHead().getNext().getNext().getData().equals(i));	
	}

	@Test
	public void testClear() {
		list.add(new Integer(5));
		list.add(new Integer(6));
		
		list.clear();
		assertTrue(list.getHead() == null);
	}

	@Test
	public void testContains() {
		list.add(i);
		list.add(j);
		
		assertTrue(list.contains(i));
		assertTrue(list.contains(j));
		assertFalse(list.contains(k));
	}

	@Test
	public void testGet() {
		list.add(i);
		list.add(j);
		
		assertTrue(list.get(0).equals(i));
		assertTrue(list.get(1).equals(j));
		
		boolean thrown = false;
		try 
		{
			list.get(3);
		}
		catch (IndexOutOfBoundsException e)
		{
			thrown = true;
		}
		 assertTrue(thrown);
		 
		 thrown = false;
		 try 
		 {
			 list.get(-1);
		 }
		 catch (IndexOutOfBoundsException e)
		 {
			 thrown = true;
		 }
		 assertTrue(thrown);
	}

	@Test
	public void testIndexOf() {
		list.add(i);
		list.add(j);
		assertTrue(list.indexOf(i) == 0);
		assertTrue(list.indexOf(j) == 1);
		assertTrue(list.indexOf(k) == -1);
		
		list = new LinkedList<Integer>();
		assertTrue(list.indexOf(k) == -1);
	}

	@Test
	public void testIsEmpty() {
		assertTrue(list.isEmpty());
		list.add(i);
		assertFalse(list.isEmpty());
	}

	@Test
	public void testRemoveInt() {
		list.add(i);
		list.add(j);
		assertTrue(list.remove(0).equals(i));
		assertFalse(list.getHead().getData().equals(i));
		System.out.println(list.getHead().getData());
		assertTrue(list.getHead().getData().equals(j));
		assertTrue(list.remove(0).equals(j));
		assertTrue(list.getHead() == null);
		list.add(i);
		list.add(j);
		assertTrue(list.remove(1).equals(j));
		assertTrue(list.getHead().getNext().getData() == i);
		
		boolean thrown = false;
		try 
		{
			list.remove(1);
		}
		catch (IndexOutOfBoundsException e)
		{
			thrown = true;
		}
		 assertTrue(thrown);
		 
		 thrown = false;
		 try 
		 {
			 list.remove(-1);
		 }
		 catch (IndexOutOfBoundsException e)
		 {
			 thrown = true;
		 }
		 assertTrue(thrown);
		
	}

	@Test
	public void testRemoveObject() {
		list.add(i);
		list.add(j);
		assertTrue(list.remove(j).equals(j));
		assertTrue(list.remove(i).equals(i));
		assertNull(list.remove(k));
	}

	@Test
	public void testSet() {
		list.add(i);
		list.add(j);
		assertEquals(list.set(1, k), j);
		assertEquals(list.get(0), i);
		assertEquals(list.get(1), k);
		
		boolean thrown = false;
		try 
		{
			list.set(2, j);
		}
		catch (IndexOutOfBoundsException e)
		{
			thrown = true;
		}
		 assertTrue(thrown);
		 
		 thrown = false;
		 try 
		 {
			 list.set(-1, j);
		 }
		 catch (IndexOutOfBoundsException e)
		 {
			 thrown = true;
		 }
		 assertTrue(thrown);
	}

	@Test
	public void testSize() {
		assertEquals(list.size(), 0);
		list.add(i);
		assertEquals(list.size(), 1);
		list.remove(i);
		assertEquals(list.size(), 0);
		
	}
	
}