test/tck/LinkedListTest.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

import junit.framework.*;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;

public class LinkedListTest extends JSR166TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(suite());
    }

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

    /**
     * Create a queue of given size containing consecutive
     * Integers 0 ... n.
     */
    private LinkedList<Integer> populatedQueue(int n) {
        LinkedList<Integer> q = new LinkedList<Integer>();
        assertTrue(q.isEmpty());
        for (int i = 0; i < n; ++i)
            assertTrue(q.offer(new Integer(i)));
        assertFalse(q.isEmpty());
        assertEquals(n, q.size());
        return q;
    }

    /**
     * new queue is empty
     */
    public void testConstructor1() {
        assertEquals(0, new LinkedList().size());
    }

    /**
     * Initializing from null Collection throws NPE
     */
    public void testConstructor3() {
        try {
            LinkedList q = new LinkedList((Collection)null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements of collection used to initialize
     */
    public void testConstructor6() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = i;
        LinkedList q = new LinkedList(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * isEmpty is true before add, false after
     */
    public void testEmpty() {
        LinkedList q = new LinkedList();
        assertTrue(q.isEmpty());
        q.add(new Integer(1));
        assertFalse(q.isEmpty());
        q.add(new Integer(2));
        q.remove();
        q.remove();
        assertTrue(q.isEmpty());
    }

    /**
     * size changes when elements added and removed
     */
    public void testSize() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(SIZE-i, q.size());
            q.remove();
        }
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            q.add(new Integer(i));
        }
    }

    /**
     * offer(null) succeeds
     */
    public void testOfferNull() {
        LinkedList q = new LinkedList();
        q.offer(null);
    }

    /**
     * Offer succeeds
     */
    public void testOffer() {
        LinkedList q = new LinkedList();
        assertTrue(q.offer(new Integer(0)));
        assertTrue(q.offer(new Integer(1)));
    }

    /**
     * add succeeds
     */
    public void testAdd() {
        LinkedList q = new LinkedList();
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            assertTrue(q.add(new Integer(i)));
        }
    }

    /**
     * addAll(null) throws NPE
     */
    public void testAddAll1() {
        try {
            LinkedList q = new LinkedList();
            q.addAll(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements, in traversal order, of successful addAll
     */
    public void testAddAll5() {
        Integer[] empty = new Integer[0];
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = i;
        LinkedList q = new LinkedList();
        assertFalse(q.addAll(Arrays.asList(empty)));
        assertTrue(q.addAll(Arrays.asList(ints)));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * addAll with too large an index throws IOOBE
     */
    public void testAddAll2_IndexOutOfBoundsException() {
        LinkedList l = new LinkedList();
        l.add(new Object());
        LinkedList m = new LinkedList();
        m.add(new Object());
        try {
            l.addAll(4,m);
            shouldThrow();
        } catch (IndexOutOfBoundsException success) {}
    }

    /**
     * addAll with negative index throws IOOBE
     */
    public void testAddAll4_BadIndex() {
        LinkedList l = new LinkedList();
        l.add(new Object());
        LinkedList m = new LinkedList();
        m.add(new Object());
        try {
            l.addAll(-1,m);
            shouldThrow();
        } catch (IndexOutOfBoundsException success) {}
    }

    /**
     * poll succeeds unless empty
     */
    public void testPoll() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.poll());
        }
        assertNull(q.poll());
    }

    /**
     * peek returns next element, or null if empty
     */
    public void testPeek() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peek());
            assertEquals(i, q.poll());
            assertTrue(q.peek() == null ||
                       !q.peek().equals(i));
        }
        assertNull(q.peek());
    }

    /**
     * element returns next element, or throws NSEE if empty
     */
    public void testElement() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.element());
            assertEquals(i, q.poll());
        }
        try {
            q.element();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove removes next element, or throws NSEE if empty
     */
    public void testRemove() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.remove());
        }
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove(x) removes x and returns true if present
     */
    public void testRemoveElement() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove((Integer)i));
            assertFalse(q.contains(i));
            assertTrue(q.contains(i-1));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove((Integer)i));
            assertFalse(q.contains(i));
            assertFalse(q.remove((Integer)(i+1)));
            assertFalse(q.contains(i+1));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * contains(x) reports true when elements added but not yet removed
     */
    public void testContains() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.contains(new Integer(i)));
            q.poll();
            assertFalse(q.contains(new Integer(i)));
        }
    }

    /**
     * clear removes all elements
     */
    public void testClear() {
        LinkedList q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertTrue(q.add(new Integer(1)));
        assertFalse(q.isEmpty());
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll(c) is true when c contains a subset of elements
     */
    public void testContainsAll() {
        LinkedList q = populatedQueue(SIZE);
        LinkedList p = new LinkedList();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            assertTrue(p.add(new Integer(i)));
        }
        assertTrue(p.containsAll(q));
    }

    /**
     * retainAll(c) retains only those elements of c and reports true if changed
     */
    public void testRetainAll() {
        LinkedList q = populatedQueue(SIZE);
        LinkedList p = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            boolean changed = q.retainAll(p);
            if (i == 0)
                assertFalse(changed);
            else
                assertTrue(changed);

            assertTrue(q.containsAll(p));
            assertEquals(SIZE-i, q.size());
            p.remove();
        }
    }

    /**
     * removeAll(c) removes only those elements of c and reports true if changed
     */
    public void testRemoveAll() {
        for (int i = 1; i < SIZE; ++i) {
            LinkedList q = populatedQueue(SIZE);
            LinkedList p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE-i, q.size());
            for (int j = 0; j < i; ++j) {
                Integer I = (Integer)(p.remove());
                assertFalse(q.contains(I));
            }
        }
    }

    /**
     * toArray contains all elements in FIFO order
     */
    public void testToArray() {
        LinkedList q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        for (int i = 0; i < o.length; i++)
            assertSame(o[i], q.poll());
    }

    /**
     * toArray(a) contains all elements in FIFO order
     */
    public void testToArray2() {
        LinkedList<Integer> q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        Integer[] array = q.toArray(ints);
        assertSame(ints, array);
        for (int i = 0; i < ints.length; i++)
            assertSame(ints[i], q.poll());
    }

    /**
     * toArray(null) throws NullPointerException
     */
    public void testToArray_NullArg() {
        LinkedList l = new LinkedList();
        l.add(new Object());
        try {
            l.toArray(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * toArray(incompatible array type) throws ArrayStoreException
     */
    public void testToArray1_BadArg() {
        LinkedList l = new LinkedList();
        l.add(new Integer(5));
        try {
            l.toArray(new String[10]);
            shouldThrow();
        } catch (ArrayStoreException success) {}
    }

    /**
     * iterator iterates through all elements
     */
    public void testIterator() {
        LinkedList q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.iterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
    }

    /**
     * iterator ordering is FIFO
     */
    public void testIteratorOrdering() {
        final LinkedList q = new LinkedList();
        q.add(new Integer(1));
        q.add(new Integer(2));
        q.add(new Integer(3));
        int k = 0;
        for (Iterator it = q.iterator(); it.hasNext();) {
            assertEquals(++k, it.next());
        }

        assertEquals(3, k);
    }

    /**
     * iterator.remove removes current element
     */
    public void testIteratorRemove() {
        final LinkedList q = new LinkedList();
        q.add(new Integer(1));
        q.add(new Integer(2));
        q.add(new Integer(3));
        Iterator it = q.iterator();
        assertEquals(it.next(), 1);
        it.remove();
        it = q.iterator();
        assertEquals(it.next(), 2);
        assertEquals(it.next(), 3);
        assertFalse(it.hasNext());
    }

    /**
     * Descending iterator iterates through all elements
     */
    public void testDescendingIterator() {
        LinkedList q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.descendingIterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
        assertFalse(it.hasNext());
        try {
            it.next();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * Descending iterator ordering is reverse FIFO
     */
    public void testDescendingIteratorOrdering() {
        final LinkedList q = new LinkedList();
        q.add(new Integer(3));
        q.add(new Integer(2));
        q.add(new Integer(1));
        int k = 0;
        for (Iterator it = q.descendingIterator(); it.hasNext();) {
            assertEquals(++k, it.next());
        }

        assertEquals(3, k);
    }

    /**
     * descendingIterator.remove removes current element
     */
    public void testDescendingIteratorRemove() {
        final LinkedList q = new LinkedList();
        q.add(three);
        q.add(two);
        q.add(one);
        Iterator it = q.descendingIterator();
        it.next();
        it.remove();
        it = q.descendingIterator();
        assertSame(it.next(), two);
        assertSame(it.next(), three);
        assertFalse(it.hasNext());
    }

    /**
     * toString contains toStrings of elements
     */
    public void testToString() {
        LinkedList q = populatedQueue(SIZE);
        String s = q.toString();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(s.contains(String.valueOf(i)));
        }
    }

    /**
     * peek returns element inserted with addFirst
     */
    public void testAddFirst() {
        LinkedList q = populatedQueue(3);
        q.addFirst(four);
        assertSame(four, q.peek());
    }

    /**
     * peekFirst returns element inserted with push
     */
    public void testPush() {
        LinkedList q = populatedQueue(3);
        q.push(four);
        assertSame(four, q.peekFirst());
    }

    /**
     * pop removes next element, or throws NSEE if empty
     */
    public void testPop() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.pop());
        }
        try {
            q.pop();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * OfferFirst succeeds
     */
    public void testOfferFirst() {
        LinkedList q = new LinkedList();
        assertTrue(q.offerFirst(new Integer(0)));
        assertTrue(q.offerFirst(new Integer(1)));
    }

    /**
     * OfferLast succeeds
     */
    public void testOfferLast() {
        LinkedList q = new LinkedList();
        assertTrue(q.offerLast(new Integer(0)));
        assertTrue(q.offerLast(new Integer(1)));
    }

    /**
     * pollLast succeeds unless empty
     */
    public void testPollLast() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.pollLast());
        }
        assertNull(q.pollLast());
    }

    /**
     * peekFirst returns next element, or null if empty
     */
    public void testPeekFirst() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peekFirst());
            assertEquals(i, q.pollFirst());
            assertTrue(q.peekFirst() == null ||
                       !q.peekFirst().equals(i));
        }
        assertNull(q.peekFirst());
    }

    /**
     * peekLast returns next element, or null if empty
     */
    public void testPeekLast() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.peekLast());
            assertEquals(i, q.pollLast());
            assertTrue(q.peekLast() == null ||
                       !q.peekLast().equals(i));
        }
        assertNull(q.peekLast());
    }

    public void testFirstElement() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.getFirst());
            assertEquals(i, q.pollFirst());
        }
        try {
            q.getFirst();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * getLast returns next element, or throws NSEE if empty
     */
    public void testLastElement() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.getLast());
            assertEquals(i, q.pollLast());
        }
        try {
            q.getLast();
            shouldThrow();
        } catch (NoSuchElementException success) {}
        assertNull(q.peekLast());
    }

    /**
     * removeFirstOccurrence(x) removes x and returns true if present
     */
    public void testRemoveFirstOccurrence() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.removeFirstOccurrence(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.removeFirstOccurrence(new Integer(i)));
            assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * removeLastOccurrence(x) removes x and returns true if present
     */
    public void testRemoveLastOccurrence() {
        LinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.removeLastOccurrence(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.removeLastOccurrence(new Integer(i)));
            assertFalse(q.removeLastOccurrence(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    }

}
Revision:	1.28
Committed:	Tue May 31 16:16:24 2011 UTC (12 years, 11 months ago) by jsr166
Branch:	MAIN
Changes since 1.27:	+5 -2 lines
Log Message:	use serialClone in serialization tests; update imports
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	* Pat Fisher, Mike Judd.
7	*/
8
9	import junit.framework.*;
10	import java.util.Arrays;
11	import java.util.Collection;
12	import java.util.Iterator;
13	import java.util.LinkedList;
14	import java.util.NoSuchElementException;
15
16	public class LinkedListTest extends JSR166TestCase {
17	public static void main(String[] args) {
18	junit.textui.TestRunner.run(suite());
19	}
20
21	public static Test suite() {
22	return new TestSuite(LinkedListTest.class);
23	}
24
25	/**
26	* Create a queue of given size containing consecutive
27	* Integers 0 ... n.
28	*/
29	private LinkedList<Integer> populatedQueue(int n) {
30	LinkedList<Integer> q = new LinkedList<Integer>();
31	assertTrue(q.isEmpty());
32	for (int i = 0; i < n; ++i)
33	assertTrue(q.offer(new Integer(i)));
34	assertFalse(q.isEmpty());
35	assertEquals(n, q.size());
36	return q;
37	}
38
39	/**
40	* new queue is empty
41	*/
42	public void testConstructor1() {
43	assertEquals(0, new LinkedList().size());
44	}
45
46	/**
47	* Initializing from null Collection throws NPE
48	*/
49	public void testConstructor3() {
50	try {
51	LinkedList q = new LinkedList((Collection)null);
52	shouldThrow();
53	} catch (NullPointerException success) {}
54	}
55
56	/**
57	* Queue contains all elements of collection used to initialize
58	*/
59	public void testConstructor6() {
60	Integer[] ints = new Integer[SIZE];
61	for (int i = 0; i < SIZE; ++i)
62	ints[i] = i;
63	LinkedList q = new LinkedList(Arrays.asList(ints));
64	for (int i = 0; i < SIZE; ++i)
65	assertEquals(ints[i], q.poll());
66	}
67
68	/**
69	* isEmpty is true before add, false after
70	*/
71	public void testEmpty() {
72	LinkedList q = new LinkedList();
73	assertTrue(q.isEmpty());
74	q.add(new Integer(1));
75	assertFalse(q.isEmpty());
76	q.add(new Integer(2));
77	q.remove();
78	q.remove();
79	assertTrue(q.isEmpty());
80	}
81
82	/**
83	* size changes when elements added and removed
84	*/
85	public void testSize() {
86	LinkedList q = populatedQueue(SIZE);
87	for (int i = 0; i < SIZE; ++i) {
88	assertEquals(SIZE-i, q.size());
89	q.remove();
90	}
91	for (int i = 0; i < SIZE; ++i) {
92	assertEquals(i, q.size());
93	q.add(new Integer(i));
94	}
95	}
96
97	/**
98	* offer(null) succeeds
99	*/
100	public void testOfferNull() {
101	LinkedList q = new LinkedList();
102	q.offer(null);
103	}
104
105	/**
106	* Offer succeeds
107	*/
108	public void testOffer() {
109	LinkedList q = new LinkedList();
110	assertTrue(q.offer(new Integer(0)));
111	assertTrue(q.offer(new Integer(1)));
112	}
113
114	/**
115	* add succeeds
116	*/
117	public void testAdd() {
118	LinkedList q = new LinkedList();
119	for (int i = 0; i < SIZE; ++i) {
120	assertEquals(i, q.size());
121	assertTrue(q.add(new Integer(i)));
122	}
123	}
124
125	/**
126	* addAll(null) throws NPE
127	*/
128	public void testAddAll1() {
129	try {
130	LinkedList q = new LinkedList();
131	q.addAll(null);
132	shouldThrow();
133	} catch (NullPointerException success) {}
134	}
135
136	/**
137	* Queue contains all elements, in traversal order, of successful addAll
138	*/
139	public void testAddAll5() {
140	Integer[] empty = new Integer[0];
141	Integer[] ints = new Integer[SIZE];
142	for (int i = 0; i < SIZE; ++i)
143	ints[i] = i;
144	LinkedList q = new LinkedList();
145	assertFalse(q.addAll(Arrays.asList(empty)));
146	assertTrue(q.addAll(Arrays.asList(ints)));
147	for (int i = 0; i < SIZE; ++i)
148	assertEquals(ints[i], q.poll());
149	}
150
151	/**
152	* addAll with too large an index throws IOOBE
153	*/
154	public void testAddAll2_IndexOutOfBoundsException() {
155	LinkedList l = new LinkedList();
156	l.add(new Object());
157	LinkedList m = new LinkedList();
158	m.add(new Object());
159	try {
160	l.addAll(4,m);
161	shouldThrow();
162	} catch (IndexOutOfBoundsException success) {}
163	}
164
165	/**
166	* addAll with negative index throws IOOBE
167	*/
168	public void testAddAll4_BadIndex() {
169	LinkedList l = new LinkedList();
170	l.add(new Object());
171	LinkedList m = new LinkedList();
172	m.add(new Object());
173	try {
174	l.addAll(-1,m);
175	shouldThrow();
176	} catch (IndexOutOfBoundsException success) {}
177	}
178
179	/**
180	* poll succeeds unless empty
181	*/
182	public void testPoll() {
183	LinkedList q = populatedQueue(SIZE);
184	for (int i = 0; i < SIZE; ++i) {
185	assertEquals(i, q.poll());
186	}
187	assertNull(q.poll());
188	}
189
190	/**
191	* peek returns next element, or null if empty
192	*/
193	public void testPeek() {
194	LinkedList q = populatedQueue(SIZE);
195	for (int i = 0; i < SIZE; ++i) {
196	assertEquals(i, q.peek());
197	assertEquals(i, q.poll());
198	assertTrue(q.peek() == null \|\|
199	!q.peek().equals(i));
200	}
201	assertNull(q.peek());
202	}
203
204	/**
205	* element returns next element, or throws NSEE if empty
206	*/
207	public void testElement() {
208	LinkedList q = populatedQueue(SIZE);
209	for (int i = 0; i < SIZE; ++i) {
210	assertEquals(i, q.element());
211	assertEquals(i, q.poll());
212	}
213	try {
214	q.element();
215	shouldThrow();
216	} catch (NoSuchElementException success) {}
217	}
218
219	/**
220	* remove removes next element, or throws NSEE if empty
221	*/
222	public void testRemove() {
223	LinkedList q = populatedQueue(SIZE);
224	for (int i = 0; i < SIZE; ++i) {
225	assertEquals(i, q.remove());
226	}
227	try {
228	q.remove();
229	shouldThrow();
230	} catch (NoSuchElementException success) {}
231	}
232
233	/**
234	* remove(x) removes x and returns true if present
235	*/
236	public void testRemoveElement() {
237	LinkedList q = populatedQueue(SIZE);
238	for (int i = 1; i < SIZE; i+=2) {
239	assertTrue(q.contains(i));
240	assertTrue(q.remove((Integer)i));
241	assertFalse(q.contains(i));
242	assertTrue(q.contains(i-1));
243	}
244	for (int i = 0; i < SIZE; i+=2) {
245	assertTrue(q.contains(i));
246	assertTrue(q.remove((Integer)i));
247	assertFalse(q.contains(i));
248	assertFalse(q.remove((Integer)(i+1)));
249	assertFalse(q.contains(i+1));
250	}
251	assertTrue(q.isEmpty());
252	}
253
254	/**
255	* contains(x) reports true when elements added but not yet removed
256	*/
257	public void testContains() {
258	LinkedList q = populatedQueue(SIZE);
259	for (int i = 0; i < SIZE; ++i) {
260	assertTrue(q.contains(new Integer(i)));
261	q.poll();
262	assertFalse(q.contains(new Integer(i)));
263	}
264	}
265
266	/**
267	* clear removes all elements
268	*/
269	public void testClear() {
270	LinkedList q = populatedQueue(SIZE);
271	q.clear();
272	assertTrue(q.isEmpty());
273	assertEquals(0, q.size());
274	assertTrue(q.add(new Integer(1)));
275	assertFalse(q.isEmpty());
276	q.clear();
277	assertTrue(q.isEmpty());
278	}
279
280	/**
281	* containsAll(c) is true when c contains a subset of elements
282	*/
283	public void testContainsAll() {
284	LinkedList q = populatedQueue(SIZE);
285	LinkedList p = new LinkedList();
286	for (int i = 0; i < SIZE; ++i) {
287	assertTrue(q.containsAll(p));
288	assertFalse(p.containsAll(q));
289	assertTrue(p.add(new Integer(i)));
290	}
291	assertTrue(p.containsAll(q));
292	}
293
294	/**
295	* retainAll(c) retains only those elements of c and reports true if changed
296	*/
297	public void testRetainAll() {
298	LinkedList q = populatedQueue(SIZE);
299	LinkedList p = populatedQueue(SIZE);
300	for (int i = 0; i < SIZE; ++i) {
301	boolean changed = q.retainAll(p);
302	if (i == 0)
303	assertFalse(changed);
304	else
305	assertTrue(changed);
306
307	assertTrue(q.containsAll(p));
308	assertEquals(SIZE-i, q.size());
309	p.remove();
310	}
311	}
312
313	/**
314	* removeAll(c) removes only those elements of c and reports true if changed
315	*/
316	public void testRemoveAll() {
317	for (int i = 1; i < SIZE; ++i) {
318	LinkedList q = populatedQueue(SIZE);
319	LinkedList p = populatedQueue(i);
320	assertTrue(q.removeAll(p));
321	assertEquals(SIZE-i, q.size());
322	for (int j = 0; j < i; ++j) {
323	Integer I = (Integer)(p.remove());
324	assertFalse(q.contains(I));
325	}
326	}
327	}
328
329	/**
330	* toArray contains all elements in FIFO order
331	*/
332	public void testToArray() {
333	LinkedList q = populatedQueue(SIZE);
334	Object[] o = q.toArray();
335	for (int i = 0; i < o.length; i++)
336	assertSame(o[i], q.poll());
337	}
338
339	/**
340	* toArray(a) contains all elements in FIFO order
341	*/
342	public void testToArray2() {
343	LinkedList<Integer> q = populatedQueue(SIZE);
344	Integer[] ints = new Integer[SIZE];
345	Integer[] array = q.toArray(ints);
346	assertSame(ints, array);
347	for (int i = 0; i < ints.length; i++)
348	assertSame(ints[i], q.poll());
349	}
350
351	/**
352	* toArray(null) throws NullPointerException
353	*/
354	public void testToArray_NullArg() {
355	LinkedList l = new LinkedList();
356	l.add(new Object());
357	try {
358	l.toArray(null);
359	shouldThrow();
360	} catch (NullPointerException success) {}
361	}
362
363	/**
364	* toArray(incompatible array type) throws ArrayStoreException
365	*/
366	public void testToArray1_BadArg() {
367	LinkedList l = new LinkedList();
368	l.add(new Integer(5));
369	try {
370	l.toArray(new String[10]);
371	shouldThrow();
372	} catch (ArrayStoreException success) {}
373	}
374
375	/**
376	* iterator iterates through all elements
377	*/
378	public void testIterator() {
379	LinkedList q = populatedQueue(SIZE);
380	int i = 0;
381	Iterator it = q.iterator();
382	while (it.hasNext()) {
383	assertTrue(q.contains(it.next()));
384	++i;
385	}
386	assertEquals(i, SIZE);
387	}
388
389	/**
390	* iterator ordering is FIFO
391	*/
392	public void testIteratorOrdering() {
393	final LinkedList q = new LinkedList();
394	q.add(new Integer(1));
395	q.add(new Integer(2));
396	q.add(new Integer(3));
397	int k = 0;
398	for (Iterator it = q.iterator(); it.hasNext();) {
399	assertEquals(++k, it.next());
400	}
401
402	assertEquals(3, k);
403	}
404
405	/**
406	* iterator.remove removes current element
407	*/
408	public void testIteratorRemove() {
409	final LinkedList q = new LinkedList();
410	q.add(new Integer(1));
411	q.add(new Integer(2));
412	q.add(new Integer(3));
413	Iterator it = q.iterator();
414	assertEquals(it.next(), 1);
415	it.remove();
416	it = q.iterator();
417	assertEquals(it.next(), 2);
418	assertEquals(it.next(), 3);
419	assertFalse(it.hasNext());
420	}
421
422	/**
423	* Descending iterator iterates through all elements
424	*/
425	public void testDescendingIterator() {
426	LinkedList q = populatedQueue(SIZE);
427	int i = 0;
428	Iterator it = q.descendingIterator();
429	while (it.hasNext()) {
430	assertTrue(q.contains(it.next()));
431	++i;
432	}
433	assertEquals(i, SIZE);
434	assertFalse(it.hasNext());
435	try {
436	it.next();
437	shouldThrow();
438	} catch (NoSuchElementException success) {}
439	}
440
441	/**
442	* Descending iterator ordering is reverse FIFO
443	*/
444	public void testDescendingIteratorOrdering() {
445	final LinkedList q = new LinkedList();
446	q.add(new Integer(3));
447	q.add(new Integer(2));
448	q.add(new Integer(1));
449	int k = 0;
450	for (Iterator it = q.descendingIterator(); it.hasNext();) {
451	assertEquals(++k, it.next());
452	}
453
454	assertEquals(3, k);
455	}
456
457	/**
458	* descendingIterator.remove removes current element
459	*/
460	public void testDescendingIteratorRemove() {
461	final LinkedList q = new LinkedList();
462	q.add(three);
463	q.add(two);
464	q.add(one);
465	Iterator it = q.descendingIterator();
466	it.next();
467	it.remove();
468	it = q.descendingIterator();
469	assertSame(it.next(), two);
470	assertSame(it.next(), three);
471	assertFalse(it.hasNext());
472	}
473
474	/**
475	* toString contains toStrings of elements
476	*/
477	public void testToString() {
478	LinkedList q = populatedQueue(SIZE);
479	String s = q.toString();
480	for (int i = 0; i < SIZE; ++i) {
481	assertTrue(s.contains(String.valueOf(i)));
482	}
483	}
484
485	/**
486	* peek returns element inserted with addFirst
487	*/
488	public void testAddFirst() {
489	LinkedList q = populatedQueue(3);
490	q.addFirst(four);
491	assertSame(four, q.peek());
492	}
493
494	/**
495	* peekFirst returns element inserted with push
496	*/
497	public void testPush() {
498	LinkedList q = populatedQueue(3);
499	q.push(four);
500	assertSame(four, q.peekFirst());
501	}
502
503	/**
504	* pop removes next element, or throws NSEE if empty
505	*/
506	public void testPop() {
507	LinkedList q = populatedQueue(SIZE);
508	for (int i = 0; i < SIZE; ++i) {
509	assertEquals(i, q.pop());
510	}
511	try {
512	q.pop();
513	shouldThrow();
514	} catch (NoSuchElementException success) {}
515	}
516
517	/**
518	* OfferFirst succeeds
519	*/
520	public void testOfferFirst() {
521	LinkedList q = new LinkedList();
522	assertTrue(q.offerFirst(new Integer(0)));
523	assertTrue(q.offerFirst(new Integer(1)));
524	}
525
526	/**
527	* OfferLast succeeds
528	*/
529	public void testOfferLast() {
530	LinkedList q = new LinkedList();
531	assertTrue(q.offerLast(new Integer(0)));
532	assertTrue(q.offerLast(new Integer(1)));
533	}
534
535	/**
536	* pollLast succeeds unless empty
537	*/
538	public void testPollLast() {
539	LinkedList q = populatedQueue(SIZE);
540	for (int i = SIZE-1; i >= 0; --i) {
541	assertEquals(i, q.pollLast());
542	}
543	assertNull(q.pollLast());
544	}
545
546	/**
547	* peekFirst returns next element, or null if empty
548	*/
549	public void testPeekFirst() {
550	LinkedList q = populatedQueue(SIZE);
551	for (int i = 0; i < SIZE; ++i) {
552	assertEquals(i, q.peekFirst());
553	assertEquals(i, q.pollFirst());
554	assertTrue(q.peekFirst() == null \|\|
555	!q.peekFirst().equals(i));
556	}
557	assertNull(q.peekFirst());
558	}
559
560	/**
561	* peekLast returns next element, or null if empty
562	*/
563	public void testPeekLast() {
564	LinkedList q = populatedQueue(SIZE);
565	for (int i = SIZE-1; i >= 0; --i) {
566	assertEquals(i, q.peekLast());
567	assertEquals(i, q.pollLast());
568	assertTrue(q.peekLast() == null \|\|
569	!q.peekLast().equals(i));
570	}
571	assertNull(q.peekLast());
572	}
573
574	public void testFirstElement() {
575	LinkedList q = populatedQueue(SIZE);
576	for (int i = 0; i < SIZE; ++i) {
577	assertEquals(i, q.getFirst());
578	assertEquals(i, q.pollFirst());
579	}
580	try {
581	q.getFirst();
582	shouldThrow();
583	} catch (NoSuchElementException success) {}
584	}
585
586	/**
587	* getLast returns next element, or throws NSEE if empty
588	*/
589	public void testLastElement() {
590	LinkedList q = populatedQueue(SIZE);
591	for (int i = SIZE-1; i >= 0; --i) {
592	assertEquals(i, q.getLast());
593	assertEquals(i, q.pollLast());
594	}
595	try {
596	q.getLast();
597	shouldThrow();
598	} catch (NoSuchElementException success) {}
599	assertNull(q.peekLast());
600	}
601
602	/**
603	* removeFirstOccurrence(x) removes x and returns true if present
604	*/
605	public void testRemoveFirstOccurrence() {
606	LinkedList q = populatedQueue(SIZE);
607	for (int i = 1; i < SIZE; i+=2) {
608	assertTrue(q.removeFirstOccurrence(new Integer(i)));
609	}
610	for (int i = 0; i < SIZE; i+=2) {
611	assertTrue(q.removeFirstOccurrence(new Integer(i)));
612	assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
613	}
614	assertTrue(q.isEmpty());
615	}
616
617	/**
618	* removeLastOccurrence(x) removes x and returns true if present
619	*/
620	public void testRemoveLastOccurrence() {
621	LinkedList q = populatedQueue(SIZE);
622	for (int i = 1; i < SIZE; i+=2) {
623	assertTrue(q.removeLastOccurrence(new Integer(i)));
624	}
625	for (int i = 0; i < SIZE; i+=2) {
626	assertTrue(q.removeLastOccurrence(new Integer(i)));
627	assertFalse(q.removeLastOccurrence(new Integer(i+1)));
628	}
629	assertTrue(q.isEmpty());
630	}
631
632	}