NullListIteratorTests.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.test.utility.iterators;

import java.util.ListIterator;
import java.util.NoSuchElementException;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import org.eclipse.persistence.tools.workbench.utility.iterators.NullListIterator;

public class NullListIteratorTests extends TestCase {

    public static Test suite() {
        return new TestSuite(NullListIteratorTests.class);
    }

    public NullListIteratorTests(String name) {
        super(name);
    }

    public void testHasNext() {
        int i = 0;
        for (ListIterator stream = NullListIterator.instance(); stream.hasNext(); ) {
            stream.next();
            i++;
        }
        assertEquals(0, i);
    }

    public void testNext() {
        for (ListIterator stream = NullListIterator.instance(); stream.hasNext(); ) {
            fail("bogus element: " + stream.next());
        }
    }

    public void testNextIndex() {
        ListIterator stream = NullListIterator.instance();
        assertEquals(0, stream.nextIndex());
    }

    public void testHasPrevious() {
        ListIterator stream = NullListIterator.instance();
        int i = 0;
        while (stream.hasPrevious()) {
            stream.previous();
            i++;
        }
        assertEquals(0, i);

        while (stream.hasNext()) {
            stream.next();
        }
        i = 0;
        while (stream.hasPrevious()) {
            stream.previous();
            i++;
        }
        assertEquals(0, i);
    }

    public void testPrevious() {
        ListIterator stream = NullListIterator.instance();
        while (stream.hasPrevious()) {
            fail("bogus element: " + stream.previous());
        }
        while (stream.hasNext()) {
            stream.next();
        }
        while (stream.hasPrevious()) {
            fail("bogus element: " + stream.previous());
        }
    }

    public void testPreviousIndex() {
        ListIterator stream = NullListIterator.instance();
        assertEquals(-1, stream.previousIndex());
    }

    public void testNoSuchElementException() {
        boolean exCaught = false;
        ListIterator stream = NullListIterator.instance();
        Object element = null;
        while (stream.hasNext()) {
            element = stream.next();
        }
        try {
            element = stream.next();
        } catch (NoSuchElementException ex) {
            exCaught = true;
        }
        assertTrue("NoSuchElementException not thrown (next): " + element, exCaught);
        while (stream.hasPrevious()) {
            element = stream.previous();
        }
        try {
            element = stream.previous();
        } catch (NoSuchElementException ex) {
            exCaught = true;
        }
        assertTrue("NoSuchElementException not thrown (previous): " + element, exCaught);
    }

    public void testUnsupportedOperationException() {
        boolean exCaught = false;
        try {
            NullListIterator.instance().remove();
        } catch (UnsupportedOperationException ex) {
            exCaught = true;
        }
        assertTrue("UnsupportedOperationException not thrown (remove)", exCaught);
        try {
            NullListIterator.instance().set(new Object());
        } catch (UnsupportedOperationException ex) {
            exCaught = true;
        }
        assertTrue("UnsupportedOperationException not thrown (set)", exCaught);
        try {
            NullListIterator.instance().add(new Object());
        } catch (UnsupportedOperationException ex) {
            exCaught = true;
        }
        assertTrue("UnsupportedOperationException not thrown (add)", exCaught);
    }

}