hashlisttest.java

A static analysis tool to find bugs in Java programs

/*
 * FindBugs - Find Bugs in Java programs
 * Copyright (C) 2006, University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.gui2;

import java.util.Collection;
import java.util.Collections;

import junit.framework.TestCase;

/**
 * @author pugh
 */
public class HashListTest extends TestCase {

	/**
	 * 
	 */
	private static final BadHasher ZERO = new BadHasher(0);
	private static final BadHasher ONE = new BadHasher(1);

	private static final BadHasher TWO = new BadHasher(2);

	private static final BadHasher THREE = new BadHasher(3);

	public void testAdd() {
		HashList<Integer> lst = new HashList<Integer>();
		lst.add(0,1);
		lst.add(0,2);
		lst.add(0,3);
		assertEquals(2,lst.indexOf(1));
		assertEquals(1,lst.indexOf(2));
		assertEquals(0,lst.indexOf(3));
	}
	public void testBadHasher() {
		HashList<BadHasher> lst = new HashList<BadHasher>();
		lst.add(0,ZERO);
		lst.add(0,ONE);
		lst.add(1,TWO);
		// lst.add(0,THREE);
		assertEquals(2,lst.indexOf(ZERO));
		assertEquals(0,lst.indexOf(ONE));
		assertEquals(1,lst.indexOf(TWO));
	}

	static class BadHasher {
		int value;
		public BadHasher(int value) {
			this.value = value;
		}
		@Override
		public String toString() {
			return Integer.toString(value);
		}
		@Override
		public int hashCode() {
			return 42;
		}
		@Override
		public boolean equals(Object v) {
			if (!(v instanceof BadHasher)) return false;
			return value == ((BadHasher)v).value;
		}
	}
	public void testRetainAllEmptu() {
		HashList<Integer> lst = new HashList<Integer>();
		lst.add(0,1);
		lst.add(0,2);
		lst.add(0,3);
		lst.retainAll(Collections.emptySet());
		assertEquals(0, lst.size());

	}

	public void testRetainAllEven() {
		HashList<BadHasher> lst = new HashList<BadHasher>();
		for(int i = 0; i < 20; i++)
			lst.add(new BadHasher(i));
		HashList<BadHasher> even = new HashList<BadHasher>();
		for(int i = 0; i < 20; i+=2)
			even.add(new BadHasher(i));
		lst.retainAll(even);
		assertEquals(10, lst.size());

	}

}