| /* | 
 |  * 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.ArrayList; | 
 | import java.util.Arrays; | 
 | import java.util.Collection; | 
 | import java.util.Collections; | 
 | import java.util.HashSet; | 
 | import java.util.Iterator; | 
 | import java.util.List; | 
 | import java.util.NoSuchElementException; | 
 | import java.util.Set; | 
 |  | 
 |  | 
 | /** | 
 |  * Tests base {@link java.util.Collection} methods and contracts. | 
 |  * <p> | 
 |  * You should create a concrete subclass of this class to test any custom | 
 |  * {@link Collection} implementation.  At minimum, you'll have to  | 
 |  * implement the {@link #makeCollection()} method.  You might want to  | 
 |  * override some of the additional protected methods as well:<P> | 
 |  * | 
 |  * <B>Element Population Methods</B><P> | 
 |  *  | 
 |  * Override these if your collection restricts what kind of elements are | 
 |  * allowed (for instance, if <Code>null</Code> is not permitted): | 
 |  * <UL> | 
 |  * <Li>{@link #getFullElements()} | 
 |  * <Li>{@link #getOtherElements()} | 
 |  * </UL> | 
 |  * | 
 |  * <B>Supported Operation Methods</B><P> | 
 |  * | 
 |  * Override these if your collection doesn't support certain operations: | 
 |  * <UL> | 
 |  * <LI>{@link #isAddSuppoted()} | 
 |  * <LI>{@link #isRemoveSupported()} | 
 |  * <li>{@link #areEqualElementsDistinguishable()} | 
 |  * </UL> | 
 |  * | 
 |  * <B>Fixture Methods</B><P> | 
 |  * | 
 |  * Fixtures are used to verify that the the operation results in correct state | 
 |  * for the collection.  Basically, the operation is performed against your | 
 |  * collection implementation, and an identical operation is performed against a | 
 |  * <I>confirmed</I> collection implementation.  A confirmed collection | 
 |  * implementation is something like <Code>java.util.ArrayList</Code>, which is | 
 |  * known to conform exactly to its collection interface's contract.  After the | 
 |  * operation takes place on both your collection implementation and the | 
 |  * confirmed collection implementation, the two collections are compared to see | 
 |  * if their state is identical.  The comparison is usually much more involved | 
 |  * than a simple <Code>equals</Code> test.  This verification is used to ensure | 
 |  * proper modifications are made along with ensuring that the collection does | 
 |  * not change when read-only modifications are made.<P> | 
 |  * | 
 |  * The {@link #collection} field holds an instance of your collection | 
 |  * implementation; the {@link #confirmed} field holds an instance of the | 
 |  * confirmed collection implementation.  The {@link #resetEmpty()} and  | 
 |  * {@link #resetFull()} methods set these fields to empty or full collections, | 
 |  * so that tests can proceed from a known state.<P> | 
 |  * | 
 |  * After a modification operation to both {@link #collection} and | 
 |  * {@link #confirmed}, the {@link #verify()} method is invoked to compare | 
 |  * the results.  You may want to override {@link #verify()} to perform | 
 |  * additional verifications.  For instance, when testing the collection | 
 |  * views of a map, {@link TestMap} would override {@link #verify()} to make | 
 |  * sure the map is changed after the collection view is changed. | 
 |  * | 
 |  * If you're extending this class directly, you will have to provide  | 
 |  * implementations for the following: | 
 |  * <UL> | 
 |  * <LI>{@link #makeConfirmedCollection()} | 
 |  * <LI>{@link #makeConfirmedFullCollection()} | 
 |  * </UL> | 
 |  * | 
 |  * Those methods should provide a confirmed collection implementation  | 
 |  * that's compatible with your collection implementation.<P> | 
 |  * | 
 |  * If you're extending {@link TestList}, {@link TestSet}, | 
 |  * or {@link TestBag}, you probably don't have to worry about the | 
 |  * above methods, because those three classes already override the methods | 
 |  * to provide standard JDK confirmed collections.<P> | 
 |  * | 
 |  * <B>Other notes</B><P> | 
 |  * | 
 |  * If your {@link Collection} fails one of these tests by design, | 
 |  * you may still use this base set of cases.  Simply override the | 
 |  * test case (method) your {@link Collection} fails.  For instance, the | 
 |  * {@link #testIteratorFailFast()} method is provided since most collections | 
 |  * have fail-fast iterators; however, that's not strictly required by the | 
 |  * collection contract, so you may want to override that method to do  | 
 |  * nothing.<P> | 
 |  * | 
 |  * @author Rodney Waldhoff | 
 |  * @author Paul Jack | 
 |  * @author <a href="mailto:mas@apache.org">Michael A. Smith</a> | 
 |  * @version $Id: TestCollection.java,v 1.9.2.1 2004/05/22 12:14:05 scolebourne Exp $ | 
 |  */ | 
 | public abstract class TestCollection extends TestObject { | 
 |  | 
 |     // | 
 |     // NOTE:  | 
 |     // | 
 |     // Collection doesn't define any semantics for equals, and recommends you | 
 |     // use reference-based default behavior of Object.equals.  (And a test for | 
 |     // that already exists in TestObject).  Tests for equality of lists, sets | 
 |     // and bags will have to be written in test subclasses.  Thus, there is no | 
 |     // tests on Collection.equals nor any for Collection.hashCode. | 
 |     // | 
 |  | 
 |  | 
 |     // These fields are used by reset() and verify(), and any test | 
 |     // method that tests a modification. | 
 |  | 
 |     /**  | 
 |      *  A collection instance that will be used for testing. | 
 |      */ | 
 |     protected Collection collection; | 
 |  | 
 |     /**  | 
 |      *  Confirmed collection.  This is an instance of a collection that is | 
 |      *  confirmed to conform exactly to the java.util.Collection contract. | 
 |      *  Modification operations are tested by performing a mod on your  | 
 |      *  collection, performing the exact same mod on an equivalent confirmed | 
 |      *  collection, and then calling verify() to make sure your collection | 
 |      *  still matches the confirmed collection. | 
 |      */ | 
 |     protected Collection confirmed; | 
 |   | 
 |  | 
 |  | 
 |     /** | 
 |      *  Resets the {@link #collection} and {@link #confirmed} fields to empty | 
 |      *  collections.  Invoke this method before performing a modification | 
 |      *  test. | 
 |      */ | 
 |     protected void resetEmpty() { | 
 |         this.collection = makeCollection(); | 
 |         this.confirmed = makeConfirmedCollection(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Resets the {@link #collection} and {@link #confirmed} fields to full | 
 |      *  collections.  Invoke this method before performing a modification | 
 |      *  test. | 
 |      */ | 
 |     protected void resetFull() { | 
 |         this.collection = makeFullCollection(); | 
 |         this.confirmed = makeConfirmedFullCollection(); | 
 |     } | 
 |  | 
 |     /** | 
 |      *  Specifies whether equal elements in the collection are, in fact, | 
 |      *  distinguishable with information not readily available.  That is, if a | 
 |      *  particular value is to be removed from the collection, then there is | 
 |      *  one and only one value that can be removed, even if there are other | 
 |      *  elements which are equal to it.   | 
 |      * | 
 |      *  <P>In most collection cases, elements are not distinguishable (equal is | 
 |      *  equal), thus this method defaults to return false.  In some cases, | 
 |      *  however, they are.  For example, the collection returned from the map's | 
 |      *  values() collection view are backed by the map, so while there may be | 
 |      *  two values that are equal, their associated keys are not.  Since the | 
 |      *  keys are distinguishable, the values are. | 
 |      * | 
 |      *  <P>This flag is used to skip some verifications for iterator.remove() | 
 |      *  where it is impossible to perform an equivalent modification on the | 
 |      *  confirmed collection because it is not possible to determine which | 
 |      *  value in the confirmed collection to actually remove.  Tests that | 
 |      *  override the default (i.e. where equal elements are distinguishable), | 
 |      *  should provide additional tests on iterator.remove() to make sure the | 
 |      *  proper elements are removed when remove() is called on the iterator. | 
 |      **/ | 
 |     protected boolean areEqualElementsDistinguishable() { | 
 |         return false; | 
 |     } | 
 |  | 
 |     /** | 
 |      *  Verifies that {@link #collection} and {@link #confirmed} have  | 
 |      *  identical state. | 
 |      */ | 
 |     protected void verify() { | 
 |         int confirmedSize = confirmed.size(); | 
 |         assertEquals("Collection size should match confirmed collection's", | 
 |                      confirmedSize, collection.size()); | 
 |         assertEquals("Collection isEmpty() result should match confirmed " + | 
 |                      " collection's",  | 
 |                      confirmed.isEmpty(), collection.isEmpty()); | 
 |  | 
 |         // verify the collections are the same by attempting to match each | 
 |         // object in the collection and confirmed collection.  To account for | 
 |         // duplicates and differing orders, each confirmed element is copied | 
 |         // into an array and a flag is maintained for each element to determine | 
 |         // whether it has been matched once and only once.  If all elements in | 
 |         // the confirmed collection are matched once and only once and there | 
 |         // aren't any elements left to be matched in the collection, | 
 |         // verification is a success. | 
 |  | 
 |         // copy each collection value into an array | 
 |         Object[] confirmedValues = new Object[confirmedSize]; | 
 |  | 
 |         Iterator iter; | 
 |  | 
 |         iter = confirmed.iterator();  | 
 |         int pos = 0; | 
 |         while(iter.hasNext()) { | 
 |             confirmedValues[pos++] = iter.next(); | 
 |         } | 
 |  | 
 |         // allocate an array of boolean flags for tracking values that have | 
 |         // been matched once and only once. | 
 |         boolean[] matched = new boolean[confirmedSize]; | 
 |          | 
 |         // now iterate through the values of the collection and try to match | 
 |         // the value with one in the confirmed array. | 
 |         iter = collection.iterator(); | 
 |         while(iter.hasNext()) { | 
 |             Object o = iter.next(); | 
 |             boolean match = false; | 
 |             for(int i = 0; i < confirmedSize; i++) { | 
 |                 if(matched[i]) { | 
 |                     // skip values already matched | 
 |                     continue; | 
 |                 } | 
 |                 if(o == confirmedValues[i] || | 
 |                    (o != null && o.equals(confirmedValues[i]))) { | 
 |                     // values matched | 
 |                     matched[i] = true; | 
 |                     match = true; | 
 |                     break; | 
 |                 } | 
 |             } | 
 |             // no match found! | 
 |             if(!match) { | 
 |                 fail("Collection should not contain a value that the " + | 
 |                      "confirmed collection does not have."); | 
 |             } | 
 |         } | 
 |          | 
 |         // make sure there aren't any unmatched values | 
 |         for(int i = 0; i < confirmedSize; i++) { | 
 |             if(!matched[i]) { | 
 |                 // the collection didn't match all the confirmed values | 
 |                 fail("Collection should contain all values that are in the " + | 
 |                      "confirmed collection"); | 
 |             } | 
 |         } | 
 |     } | 
 |      | 
 |      | 
 |     /** | 
 |      *  Returns a confirmed empty collection. | 
 |      *  For instance, an {@link java.util.ArrayList} for lists or a | 
 |      *  {@link java.util.HashSet} for sets. | 
 |      * | 
 |      *  @return a confirmed empty collection | 
 |      */ | 
 |     protected abstract Collection makeConfirmedCollection(); | 
 |  | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns a confirmed full collection. | 
 |      *  For instance, an {@link java.util.ArrayList} for lists or a | 
 |      *  {@link java.util.HashSet} for sets.  The returned collection | 
 |      *  should contain the elements returned by {@link #getFullElements()}. | 
 |      * | 
 |      *  @return a confirmed full collection | 
 |      */ | 
 |     protected abstract Collection makeConfirmedFullCollection(); | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns true if the collections produced by  | 
 |      *  {@link #makeCollection()} and {@link #makeFullCollection()} | 
 |      *  support the <Code>add</Code> and <Code>addAll</Code> | 
 |      *  operations.<P> | 
 |      *  Default implementation returns true.  Override if your collection | 
 |      *  class does not support add or addAll. | 
 |      */ | 
 |     protected boolean isAddSupported() { | 
 |         return true; | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns true if the collections produced by  | 
 |      *  {@link #makeCollection()} and {@link #makeFullCollection()} | 
 |      *  support the <Code>remove</Code>, <Code>removeAll</Code>, | 
 |      *  <Code>retainAll</Code>, <Code>clear</Code> and | 
 |      *  <Code>iterator().remove()</Code> methods. | 
 |      *  Default implementation returns true.  Override if your collection | 
 |      *  class does not support removal operations. | 
 |      */ | 
 |     protected boolean isRemoveSupported() { | 
 |         return true; | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns an array of objects that are contained in a collection | 
 |      *  produced by {@link #makeFullCollection()}.  Every element in the | 
 |      *  returned array <I>must</I> be an element in a full collection.<P> | 
 |      *  The default implementation returns a heterogenous array of  | 
 |      *  objects with some duplicates and with the null element.   | 
 |      *  Override if you require specific testing elements.  Note that if you | 
 |      *  override {@link #makeFullCollection()}, you <I>must</I> override | 
 |      *  this method to reflect the contents of a full collection. | 
 |      */ | 
 |     protected Object[] getFullElements() { | 
 |         ArrayList list = new ArrayList(); | 
 |          | 
 |         list.addAll(Arrays.asList(getFullNonNullElements())); | 
 |         list.add(4, null); | 
 |         return list.toArray(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns an array of elements that are <I>not</I> contained in a | 
 |      *  full collection.  Every element in the returned array must  | 
 |      *  not exist in a collection returned by {@link #makeFullCollection()}. | 
 |      *  The default implementation returns a heterogenous array of elements | 
 |      *  without null.  Note that some of the tests add these elements | 
 |      *  to an empty or full collection, so if your collection restricts | 
 |      *  certain kinds of elements, you should override this method. | 
 |      */ | 
 |     protected Object[] getOtherElements() { | 
 |         return getOtherNonNullElements(); | 
 |     } | 
 |      | 
 |  | 
 |     /** | 
 |      * Return a new, empty {@link Collection} to be used for testing. | 
 |      */ | 
 |     protected abstract Collection makeCollection(); | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns a full collection to be used for testing.  The collection | 
 |      *  returned by this method should contain every element returned by | 
 |      *  {@link #getFullElements()}.  The default implementation, in fact, | 
 |      *  simply invokes <Code>addAll</Code> on an empty collection with | 
 |      *  the results of {@link #getFullElements()}.  Override this default | 
 |      *  if your collection doesn't support addAll. | 
 |      */ | 
 |     protected Collection makeFullCollection() { | 
 |         Collection c = makeCollection(); | 
 |         c.addAll(Arrays.asList(getFullElements())); | 
 |         return c; | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns an empty collection for Object tests. | 
 |      */ | 
 |     public Object makeObject() { | 
 |         return makeCollection(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#add(Object)}. | 
 |      */ | 
 |     public void testCollectionAdd() { | 
 |         if (!isAddSupported()) return; | 
 |          | 
 |         Object[] elements = getFullElements(); | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             resetEmpty(); | 
 |             boolean r = collection.add(elements[i]); | 
 |             confirmed.add(elements[i]); | 
 |             verify(); | 
 |             assertTrue("Empty collection changed after add", r); | 
 |             assertTrue("Collection size is 1 after first add",  | 
 |                        collection.size() == 1); | 
 |         } | 
 |          | 
 |         resetEmpty(); | 
 |         int size = 0; | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             boolean r = collection.add(elements[i]); | 
 |             confirmed.add(elements[i]); | 
 |             verify(); | 
 |             if (r) size++; | 
 |             assertEquals("Collection size should grow after add",  | 
 |                          size, collection.size()); | 
 |             assertTrue("Collection should contain added element", | 
 |                        collection.contains(elements[i])); | 
 |         } | 
 |     } | 
 |      | 
 |      | 
 |     /** | 
 |      *  Tests {@link Collection#addAll(Collection)}. | 
 |      */ | 
 |     public void testCollectionAddAll() { | 
 |         if (!isAddSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         Object[] elements = getFullElements(); | 
 |         boolean r = collection.addAll(Arrays.asList(elements)); | 
 |         confirmed.addAll(Arrays.asList(elements)); | 
 |         verify(); | 
 |         assertTrue("Empty collection should change after addAll", r); | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Collection should contain added element", | 
 |                        collection.contains(elements[i])); | 
 |         } | 
 |  | 
 |         resetFull(); | 
 |         int size = collection.size(); | 
 |         elements = getOtherElements(); | 
 |         r = collection.addAll(Arrays.asList(elements)); | 
 |         confirmed.addAll(Arrays.asList(elements)); | 
 |         verify(); | 
 |         assertTrue("Full collection should change after addAll", r); | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Full collection should contain added element", | 
 |                        collection.contains(elements[i])); | 
 |         } | 
 |         assertEquals("Size should increase after addAll",  | 
 |                      size + elements.length, collection.size()); | 
 |          | 
 |         resetFull(); | 
 |         size = collection.size(); | 
 |         r = collection.addAll(Arrays.asList(getFullElements())); | 
 |         confirmed.addAll(Arrays.asList(getFullElements())); | 
 |         verify(); | 
 |         if (r) { | 
 |             assertTrue("Size should increase if addAll returns true",  | 
 |                        size < collection.size()); | 
 |         } else { | 
 |             assertEquals("Size should not change if addAll returns false", | 
 |                          size, collection.size()); | 
 |         }  | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  If {@link #isAddSupported()} returns false, tests that add operations | 
 |      *  raise <Code>UnsupportedOperationException. | 
 |      */ | 
 |     public void testUnsupportedAdd() { | 
 |         if (isAddSupported()) return; | 
 |          | 
 |         resetEmpty(); | 
 |         try { | 
 |             collection.add(new Object()); | 
 |             fail("Emtpy collection should not support add."); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         // make sure things didn't change even if the expected exception was | 
 |         // thrown. | 
 |         verify(); | 
 |  | 
 |         try { | 
 |             collection.addAll(Arrays.asList(getFullElements())); | 
 |             fail("Emtpy collection should not support addAll."); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         // make sure things didn't change even if the expected exception was | 
 |         // thrown. | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         try { | 
 |             collection.add(new Object()); | 
 |             fail("Full collection should not support add."); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         // make sure things didn't change even if the expected exception was | 
 |         // thrown. | 
 |         verify(); | 
 |          | 
 |         try { | 
 |             collection.addAll(Arrays.asList(getOtherElements())); | 
 |             fail("Full collection should not support addAll."); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         // make sure things didn't change even if the expected exception was | 
 |         // thrown. | 
 |         verify(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Test {@link Collection#clear()}. | 
 |      */ | 
 |     public void testCollectionClear() { | 
 |         if (!isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         collection.clear(); // just to make sure it doesn't raise anything | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         collection.clear(); | 
 |         confirmed.clear(); | 
 |         verify(); | 
 |     }     | 
 |  | 
 |      | 
 |     /** | 
 |      *  Tests {@link Collection#contains(Object)}. | 
 |      */ | 
 |     public void testCollectionContains() { | 
 |         Object[] elements; | 
 |  | 
 |         resetEmpty(); | 
 |         elements = getFullElements(); | 
 |         for(int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Empty collection shouldn'y contain element", | 
 |                        !collection.contains(elements[i])); | 
 |         } | 
 |         // make sure calls to "contains" don't change anything | 
 |         verify(); | 
 |  | 
 |         elements = getOtherElements(); | 
 |         for(int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Empty collection shouldn'y contain element", | 
 |                        !collection.contains(elements[i])); | 
 |         } | 
 |         // make sure calls to "contains" don't change anything | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         elements = getFullElements(); | 
 |         for(int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Full collection should contain element.",  | 
 |                        collection.contains(elements[i])); | 
 |         } | 
 |         // make sure calls to "contains" don't change anything | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         elements = getOtherElements(); | 
 |         for(int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Full collection shouldn't contain element",  | 
 |                        !collection.contains(elements[i])); | 
 |         } | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#containsAll(Collection)}. | 
 |      */ | 
 |     public void testCollectionContainsAll() { | 
 |         resetEmpty(); | 
 |         Collection col = new HashSet(); | 
 |         assertTrue("Every Collection should contain all elements of an " + | 
 |                    "empty Collection.", collection.containsAll(col)); | 
 |         col.addAll(Arrays.asList(getOtherElements())); | 
 |         assertTrue("Empty Collection shouldn't contain all elements of " + | 
 |                    "a non-empty Collection.", !collection.containsAll(col)); | 
 |         // make sure calls to "containsAll" don't change anything | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         assertTrue("Full collection shouldn't contain other elements",  | 
 |                    !collection.containsAll(col)); | 
 |          | 
 |         col.clear(); | 
 |         col.addAll(Arrays.asList(getFullElements())); | 
 |         assertTrue("Full collection should containAll full elements", | 
 |                    collection.containsAll(col)); | 
 |         // make sure calls to "containsAll" don't change anything | 
 |         verify(); | 
 |  | 
 |           | 
 |         assertTrue("Full collection should containAll itself",  | 
 |                    collection.containsAll(collection)); | 
 |  | 
 |         // make sure calls to "containsAll" don't change anything | 
 |         verify(); | 
 |          | 
 |         col = new ArrayList(); | 
 |         col.addAll(Arrays.asList(getFullElements())); | 
 |         col.addAll(Arrays.asList(getFullElements())); | 
 |         assertTrue("Full collection should containAll duplicate full " + | 
 |                    "elements", collection.containsAll(col)); | 
 |  | 
 |         // make sure calls to "containsAll" don't change anything | 
 |         verify(); | 
 |     } | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#isEmpty()}. | 
 |      */ | 
 |     public void testCollectionIsEmpty() { | 
 |         resetEmpty(); | 
 |         assertEquals("New Collection should be empty.",  | 
 |                      true, collection.isEmpty()); | 
 |         // make sure calls to "isEmpty() don't change anything | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         assertEquals("Full collection shouldn't be empty",  | 
 |                      false, collection.isEmpty()); | 
 |         // make sure calls to "isEmpty() don't change anything | 
 |         verify(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests the read-only functionality of {@link Collection#iterator()}. | 
 |      */ | 
 |     public void testCollectionIterator() { | 
 |         resetEmpty(); | 
 |         Iterator it1 = collection.iterator(); | 
 |         assertEquals("Iterator for empty Collection shouldn't have next.", | 
 |                      false, it1.hasNext()); | 
 |         try { | 
 |             it1.next(); | 
 |             fail("Iterator at end of Collection should throw " + | 
 |                  "NoSuchElementException when next is called."); | 
 |         } catch(NoSuchElementException e) { | 
 |             // expected | 
 |         }  | 
 |         // make sure nothing has changed after non-modification | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         it1 = collection.iterator(); | 
 |         for (int i = 0; i < collection.size(); i++) { | 
 |             assertTrue("Iterator for full collection should haveNext",  | 
 |                        it1.hasNext()); | 
 |             it1.next(); | 
 |         } | 
 |         assertTrue("Iterator should be finished", !it1.hasNext()); | 
 |          | 
 |         ArrayList list = new ArrayList(); | 
 |         it1 = collection.iterator(); | 
 |         for (int i = 0; i < collection.size(); i++) { | 
 |             Object next = it1.next(); | 
 |             assertTrue("Collection should contain element returned by " + | 
 |                        "its iterator", collection.contains(next)); | 
 |             list.add(next); | 
 |         } | 
 |         try { | 
 |             it1.next(); | 
 |             fail("iterator.next() should raise NoSuchElementException " + | 
 |                  "after it finishes"); | 
 |         } catch (NoSuchElementException e) { | 
 |             // expected | 
 |         } | 
 |         // make sure nothing has changed after non-modification | 
 |         verify(); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests removals from {@link Collection#iterator()}. | 
 |      */ | 
 |     public void testCollectionIteratorRemove() { | 
 |         if (!isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         try { | 
 |             collection.iterator().remove(); | 
 |             fail("New iterator.remove should raise IllegalState"); | 
 |         } catch (IllegalStateException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         try { | 
 |             Iterator iter = collection.iterator(); | 
 |             iter.hasNext(); | 
 |             iter.remove(); | 
 |             fail("New iterator.remove should raise IllegalState " + | 
 |                  "even after hasNext"); | 
 |         } catch (IllegalStateException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         int size = collection.size(); | 
 |         Iterator iter = collection.iterator(); | 
 |         while (iter.hasNext()) { | 
 |             Object o = iter.next(); | 
 |             iter.remove(); | 
 |  | 
 |             // if the elements aren't distinguishable, we can just remove a | 
 |             // matching element from the confirmed collection and verify | 
 |             // contents are still the same.  Otherwise, we don't have the | 
 |             // ability to distinguish the elements and determine which to | 
 |             // remove from the confirmed collection (in which case, we don't | 
 |             // verify because we don't know how).  | 
 |             // | 
 |             // see areEqualElementsDistinguishable() | 
 |             if(!areEqualElementsDistinguishable()) { | 
 |                 confirmed.remove(o); | 
 |                 verify(); | 
 |             } | 
 |  | 
 |             size--; | 
 |             assertEquals("Collection should shrink by one after " + | 
 |                          "iterator.remove", size, collection.size()); | 
 |         } | 
 |         assertTrue("Collection should be empty after iterator purge", | 
 |                    collection.isEmpty()); | 
 |          | 
 |         resetFull(); | 
 |         iter = collection.iterator(); | 
 |         iter.next(); | 
 |         iter.remove(); | 
 |         try { | 
 |             iter.remove(); | 
 |             fail("Second iter.remove should raise IllegalState"); | 
 |         } catch (IllegalStateException e) { | 
 |             // expected | 
 |         } | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#remove(Object)}. | 
 |      */ | 
 |     public void testCollectionRemove() { | 
 |         if (!isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         Object[] elements = getFullElements(); | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             assertTrue("Shouldn't remove nonexistent element",  | 
 |                        !collection.remove(elements[i])); | 
 |             verify(); | 
 |         } | 
 |          | 
 |         Object[] other = getOtherElements(); | 
 |          | 
 |         resetFull(); | 
 |         for (int i = 0; i < other.length; i++) { | 
 |             assertTrue("Shouldn't remove nonexistent other element",  | 
 |                        !collection.remove(other[i])); | 
 |             verify(); | 
 |         } | 
 |          | 
 |         int size = collection.size(); | 
 |         for (int i = 0; i < elements.length; i++) { | 
 |             resetFull(); | 
 |             assertTrue("Collection should remove extant element", | 
 |                        collection.remove(elements[i])); | 
 |  | 
 |             // if the elements aren't distinguishable, we can just remove a | 
 |             // matching element from the confirmed collection and verify | 
 |             // contents are still the same.  Otherwise, we don't have the | 
 |             // ability to distinguish the elements and determine which to | 
 |             // remove from the confirmed collection (in which case, we don't | 
 |             // verify because we don't know how).  | 
 |             // | 
 |             // see areEqualElementsDistinguishable() | 
 |             if(!areEqualElementsDistinguishable()) { | 
 |                 confirmed.remove(elements[i]); | 
 |                 verify(); | 
 |             } | 
 |  | 
 |             assertEquals("Collection should shrink after remove",  | 
 |                          size - 1, collection.size()); | 
 |         } | 
 |     } | 
 |      | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#removeAll(Collection)}. | 
 |      */ | 
 |     public void testCollectionRemoveAll() { | 
 |         if (!isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         assertTrue("Emtpy collection removeAll should return false for " + | 
 |                    "empty input",  | 
 |                    !collection.removeAll(Collections.EMPTY_SET)); | 
 |         verify(); | 
 |          | 
 |         assertTrue("Emtpy collection removeAll should return false for " + | 
 |                    "nonempty input",  | 
 |                    !collection.removeAll(new ArrayList(collection))); | 
 |         verify(); | 
 |          | 
 |         resetFull(); | 
 |         assertTrue("Full collection removeAll should return false for " +  | 
 |                    "empty input",  | 
 |                    !collection.removeAll(Collections.EMPTY_SET)); | 
 |         verify(); | 
 |          | 
 |         assertTrue("Full collection removeAll should return false for " + | 
 |                    "other elements",  | 
 |                    !collection.removeAll(Arrays.asList(getOtherElements()))); | 
 |         verify(); | 
 |          | 
 |         assertTrue("Full collection removeAll should return true for " + | 
 |                    "full elements",  | 
 |                    collection.removeAll(new HashSet(collection))); | 
 |         confirmed.removeAll(new HashSet(confirmed)); | 
 |         verify(); | 
 |          | 
 |         resetFull(); | 
 |  | 
 |         int size = collection.size(); | 
 |         Object[] s = getFullElements(); | 
 |         List l = new ArrayList(); | 
 |         l.add(s[2]); l.add(s[3]); l.add(s[3]); | 
 |          | 
 |         assertTrue("Full collection removeAll should work",  | 
 |                    collection.removeAll(l)); | 
 |         confirmed.removeAll(l); | 
 |         verify(); | 
 |          | 
 |         assertTrue("Collection should shrink after removeAll",  | 
 |                    collection.size() < size); | 
 |         Iterator iter = l.iterator(); | 
 |         while (iter.hasNext()) { | 
 |             assertTrue("Collection shouldn't contain removed element", | 
 |                        !collection.contains(iter.next())); | 
 |         } | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Tests {@link Collection#retainAll(Collection)}. | 
 |      */ | 
 |     public void testCollectionRetainAll() { | 
 |         if (!isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         List elements = Arrays.asList(getFullElements()); | 
 |         List other = Arrays.asList(getOtherElements()); | 
 |         Set empty = new HashSet(); | 
 |          | 
 |         assertTrue("Empty retainAll() should return false",  | 
 |                    !collection.retainAll(empty)); | 
 |         verify(); | 
 |          | 
 |         assertTrue("Empty retainAll() should return false",  | 
 |                    !collection.retainAll(elements)); | 
 |         verify(); | 
 |          | 
 |         resetFull(); | 
 |         assertTrue("Collection should change from retainAll empty",  | 
 |                    collection.retainAll(empty)); | 
 |         confirmed.retainAll(empty); | 
 |         verify(); | 
 |          | 
 |         resetFull(); | 
 |         assertTrue("Collection changed from retainAll other",  | 
 |                    collection.retainAll(other)); | 
 |         confirmed.retainAll(other); | 
 |         verify(); | 
 |          | 
 |         resetFull(); | 
 |         int size = collection.size(); | 
 |         assertTrue("Collection shouldn't change from retainAll elements", | 
 |                    !collection.retainAll(elements)); | 
 |         verify(); | 
 |         assertEquals("Collection size shouldn't change", size,  | 
 |                      collection.size()); | 
 |          | 
 |          | 
 |         resetFull(); | 
 |         HashSet set = new HashSet(elements); | 
 |         size = collection.size(); | 
 |         assertTrue("Collection shouldn't change from retainAll without " + | 
 |                    "duplicate elements", !collection.retainAll(set)); | 
 |         verify(); | 
 |         assertEquals("Collection size didn't change from nonduplicate " + | 
 |                      "retainAll", size, collection.size()); | 
 |     } | 
 |      | 
 |      | 
 |     /** | 
 |      *  Tests {@link Collection#size()}. | 
 |      */ | 
 |     public void testCollectionSize() { | 
 |         resetEmpty(); | 
 |         assertEquals("Size of new Collection is 0.", 0, collection.size()); | 
 |  | 
 |         resetFull(); | 
 |         assertTrue("Size of full collection should be greater than zero",  | 
 |                    collection.size() > 0); | 
 |     } | 
 |  | 
 |  | 
 |    | 
 |  | 
 |     /** | 
 |      *  Tests <Code>toString</Code> on a collection. | 
 |      */ | 
 |     public void testCollectionToString() { | 
 |         resetEmpty(); | 
 |         assertTrue("toString shouldn't return null",  | 
 |                    collection.toString() != null); | 
 |  | 
 |         resetFull(); | 
 |         assertTrue("toString shouldn't return null",  | 
 |                    collection.toString() != null); | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  If isRemoveSupported() returns false, tests to see that remove | 
 |      *  operations raise an UnsupportedOperationException. | 
 |      */ | 
 |     public void testUnsupportedRemove() { | 
 |         if (isRemoveSupported()) return; | 
 |  | 
 |         resetEmpty(); | 
 |         try { | 
 |             collection.clear(); | 
 |             fail("clear should raise UnsupportedOperationException"); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         try { | 
 |             collection.remove(null); | 
 |             fail("remove should raise UnsupportedOperationException"); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         try { | 
 |             collection.removeAll(null); | 
 |             fail("removeAll should raise UnsupportedOperationException"); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         try { | 
 |             collection.retainAll(null); | 
 |             fail("removeAll should raise UnsupportedOperationException"); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |         resetFull(); | 
 |         try { | 
 |             Iterator iterator = collection.iterator(); | 
 |             iterator.next(); | 
 |             iterator.remove(); | 
 |             fail("iterator.remove should raise UnsupportedOperationException"); | 
 |         } catch (UnsupportedOperationException e) { | 
 |             // expected | 
 |         } | 
 |         verify(); | 
 |  | 
 |     } | 
 |  | 
 |   | 
 |  | 
 |     /** | 
 |      *  Returns a list of elements suitable for return by | 
 |      *  {@link #getFullElements()}.  The array returned by this method | 
 |      *  does not include null, but does include a variety of objects  | 
 |      *  of different types.  Override getFullElements to return | 
 |      *  the results of this method if your collection does not support | 
 |      *  the null element. | 
 |      */ | 
 |     public static Object[] getFullNonNullElements() { | 
 |         return new Object[] { | 
 |             new String(""), | 
 |             new String("One"), | 
 |             new Integer(2), | 
 |             "Three", | 
 |             new Integer(4), | 
 |             "One", | 
 |             new Double(5), | 
 |             new Float(6), | 
 |             "Seven", | 
 |             "Eight", | 
 |             new String("Nine"), | 
 |             new Integer(10), | 
 |             new Short((short)11), | 
 |             new Long(12), | 
 |             "Thirteen", | 
 |             "14", | 
 |             "15", | 
 |             new Byte((byte)16) | 
 |         }; | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns the default list of objects returned by  | 
 |      *  {@link #getOtherElements()}.  Includes many objects | 
 |      *  of different types. | 
 |      */ | 
 |     public static Object[] getOtherNonNullElements() { | 
 |         return new Object[] { | 
 |             new Integer(0), | 
 |             new Float(0), | 
 |             new Double(0), | 
 |             "Zero", | 
 |             new Short((short)0), | 
 |             new Byte((byte)0), | 
 |             new Long(0), | 
 |             new Character('\u0000'), | 
 |             "0" | 
 |         }; | 
 |     } | 
 |  | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns a list of string elements suitable for return by | 
 |      *  {@link #getFullElements()}.  Override getFullElements to return | 
 |      *  the results of this method if your collection does not support | 
 |      *  heterogenous elements or the null element. | 
 |      */ | 
 |     public static Object[] getFullNonNullStringElements() { | 
 |         return new Object[] { | 
 |             "If","the","dull","substance","of","my","flesh","were","thought", | 
 |             "Injurious","distance","could","not","stop","my","way", | 
 |         }; | 
 |     } | 
 |  | 
 |  | 
 |     /** | 
 |      *  Returns a list of string elements suitable for return by | 
 |      *  {@link #getOtherElements()}.  Override getOtherElements to return | 
 |      *  the results of this method if your collection does not support | 
 |      *  heterogenous elements or the null element. | 
 |      */ | 
 |     public static Object[] getOtherNonNullStringElements() { | 
 |         return new Object[] { | 
 |             "For","then","despite",/* of */"space","I","would","be","brought", | 
 |             "From","limits","far","remote","where","thou","dost","stay" | 
 |         }; | 
 |     } | 
 | } |