Unittest for the Deque class

DequeTest.java

import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;

public class DequeTest extends TestCase {
	Deque<Integer> deque;

	protected void setUp() throws Exception {
		super.setUp();
		deque = new Deque<Integer>();
	}

	protected void tearDown() throws Exception {
		super.tearDown();
		deque = null;
	}

	public void testIsEmpty() {
		assertTrue(deque.isEmpty());
		deque.addFirst(5);
		assertFalse(deque.isEmpty());
		deque.removeFirst();

		assertTrue(deque.isEmpty());
		deque.addLast(5);
		assertFalse(deque.isEmpty());
		deque.removeLast();

		try {
			deque.removeFirst();
			fail("Should throw NoSuchElementException");
		} catch (NoSuchElementException e) {
			try {
				deque.removeLast();
				fail("Should throw NoSuchElementException");
			} catch (NoSuchElementException nse) {	}
		}
	}

	public void testRemoveAtFirst() {
		deque.addFirst(5);
		deque.addFirst(15);
		deque.addFirst(2);

		assertEquals(2, (int) deque.removeFirst());
		assertEquals(15, (int) deque.removeFirst());
		assertEquals(5, (int) deque.removeFirst());
		
		try {
			deque.addFirst(null);
			fail("Should throw NullPointerException");
		}
		catch (NullPointerException e) { }
	}

	public void testRemoveAtLast() {
		deque.addLast(5);
		deque.addLast(15);
		deque.addLast(2);

		assertEquals(2, (int) deque.removeLast());
		assertEquals(15, (int) deque.removeLast());
		assertEquals(5, (int) deque.removeLast());
		
		try {
			deque.addLast(null);
			fail("Should throw NullPointerException");
		}
		catch (NullPointerException e) { }
	}

	public void testMixFirstAndLast() {
		deque.addLast(5);
		deque.addLast(15);
		deque.addFirst(8);
		deque.addFirst(33); // 33 - 8 - 5 - 15

		assertEquals(15, (int) deque.removeLast());
		assertEquals(33, (int) deque.removeFirst());
		assertEquals(8, (int) deque.removeFirst());
		assertEquals(5, (int) deque.removeLast());

		assertTrue(deque.isEmpty());
	}

	public void testIteratorFor() {
		deque.addLast(5);
		deque.addLast(15);
		deque.addLast(2);
		deque.addLast(50);
		deque.addLast(1);
		deque.addLast(25);

		int[] nums = { 5, 15, 2, 50, 1, 25 };
		int i = 0;

		for (Integer in : deque)
			assertEquals(nums[i++], (int) in);
	}

	public void testIteratorWhile() {
		deque.addLast(5);
		deque.addLast(15);
		deque.addLast(2);
		deque.addLast(50);
		deque.addLast(1);
		deque.addLast(25);

		int[] nums = { 5, 15, 2, 50, 1, 25 };
		int i = 0;

		Iterator<Integer> it = deque.iterator();

		while (it.hasNext())
			assertEquals(nums[i++], (int) it.next());
	}
}