import junit.framework.TestCase;


public class StackTest extends TestCase {

	public void test_empty() {
		Stack<?> stack = new Stack<Object>();
		assertNotNull(stack);
		assertTrue(stack.isEmpty());
		assertEquals(0, stack.size());
	}

	public void test_simple() {
		Stack<Integer> stack = new Stack<Integer>();

		stack.push(1);
		stack.push(2);
		stack.push(3);
		assertFalse(stack.isEmpty());
		assertEquals(3, stack.size());

		assertEquals(new Integer(3), stack.top());
		assertEquals(3, stack.size());

		assertEquals(new Integer(3), stack.pop());
		assertEquals(2, stack.size());
		assertEquals(new Integer(2), stack.pop());
		assertEquals(1, stack.size());
		assertEquals(new Integer(1), stack.pop());
		assertEquals(0, stack.size());
	}
}