/*
* Copyright 1999-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.collections;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
/**
* Tests base {@link Set} methods and contracts.<P>
*
* Since {@link Set} doesn't stipulate much new behavior that isn't already
* found in {@link Collection}, this class basically just adds tests for
* {@link Set#equals()} and {@link Set#hashCode()} along with an updated
* {@link #verify()} that ensures elements do not appear more than once in the
* set.<P>
*
* To use, subclass and override the {@link #makeEmptySet()}
* method. You may have to override other protected methods if your
* set is not modifiable, or if your set restricts what kinds of
* elements may be added; see {@link TestCollection} for more details.<P>
*
* @author Paul Jack
* @version $Id: TestSet.java,v 1.2.2.1 2004/05/22 12:14:05 scolebourne Exp $
*/
public abstract class TestSet extends TestCollection {
/**
* Constructor.
*
* @param name name for test
*/
public TestSet(String name) {
}
/**
* Makes an empty collection by invoking {@link #makeEmptySet()}.
*
* @return an empty collection
*/
protected final Collection makeCollection() {
return makeEmptySet();
}
/**
* Makes a full collection by invoking {@link #makeFullSet()}.
*
* @return a full collection
*/
protected final Collection makeFullCollection() {
return makeFullSet();
}
/**
* Return the {@link TestCollection#collection} fixture, but cast as a
* Set.
*/
protected Set getSet() {
return (Set)collection;
}
/**
* Returns an empty {@link HashSet} for use in modification testing.
*
* @return a confirmed empty collection
*/
protected Collection makeConfirmedCollection() {
return new HashSet();
}
/**
* Returns a full {@link HashSet} for use in modification testing.
*
* @return a confirmed full collection
*/
protected Collection makeConfirmedFullCollection() {
HashSet set = new HashSet();
set.addAll(Arrays.asList(getFullElements()));
return set;
}
/**
* Return the {@link TestCollection#confirmed} fixture, but cast as a
* Set.
**/
protected Set getConfirmedSet() {
return (Set)confirmed;
}
/**
* Makes an empty set. The returned set should have no elements.
*
* @return an empty set
*/
protected abstract Set makeEmptySet();
/**
* Makes a full set by first creating an empty set and then adding
* all the elements returned by {@link #getFullElements()}.
*
* Override if your set does not support the add operation.
*
* @return a full set
*/
protected Set makeFullSet() {
Set set = makeEmptySet();
set.addAll(Arrays.asList(getFullElements()));
return set;
}
/**
* Tests {@link Set#equals(Object)}.
*/
public void testSetEquals() {
resetEmpty();
assertEquals("Empty sets should be equal",
getSet(), getConfirmedSet());
verify();
HashSet set2 = new HashSet();
set2.add("foo");
assertTrue("Empty set shouldn't equal nonempty set",
!getSet().equals(set2));
resetFull();
assertEquals("Full sets should be equal", getSet(), getConfirmedSet());
verify();
set2.clear();
set2.addAll(Arrays.asList(getOtherElements()));
assertTrue("Sets with different contents shouldn't be equal",
!getSet().equals(set2));
}
/**
* Tests {@link Set#hashCode()}.
*/
public void testSetHashCode() {
resetEmpty();
assertEquals("Empty sets have equal hashCodes",
getSet().hashCode(), getConfirmedSet().hashCode());
resetFull();
assertEquals("Equal sets have equal hashCodes",
getSet().hashCode(), getConfirmedSet().hashCode());
}
/**
* Provides additional verifications for sets.
*/
protected void verify() {
super.verify();
assertEquals("Sets should be equal", confirmed, collection);
assertEquals("Sets should have equal hashCodes",
confirmed.hashCode(), collection.hashCode());
HashSet set = new HashSet();
Iterator iterator = collection.iterator();
while (iterator.hasNext()) {
assertTrue("Set.iterator should only return unique elements",
set.add(iterator.next()));
}
}
}