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 java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;

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

public class LinkedListTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }

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

    /**
     * Returns a new 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 {
            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 x = (Integer)(p.remove());
                assertFalse(q.contains(x));
            }
        }
    }

    /**
     * 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);
        Iterator it = q.iterator();
        int i;
        for (i = 0; it.hasNext(); i++)
            assertTrue(q.contains(it.next()));
        assertEquals(i, SIZE);
        assertIteratorExhausted(it);
    }

    /**
     * iterator of empty collection has no elements
     */
    public void testEmptyIterator() {
        assertIteratorExhausted(new LinkedList().iterator());
    }

    /**
     * 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(1, it.next());
        it.remove();
        it = q.iterator();
        assertEquals(2, it.next());
        assertEquals(3, it.next());
        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:	1.37
Committed:	Sat Apr 25 04:55:31 2015 UTC (9 years ago) by jsr166
Branch:	MAIN
Changes since 1.36:	+1 -1 lines
Log Message:	improve main methods; respect system properties; actually fail if a test fails
#	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 java.util.Arrays;
10	import java.util.Collection;
11	import java.util.Iterator;
12	import java.util.LinkedList;
13	import java.util.NoSuchElementException;
14
15	import junit.framework.Test;
16	import junit.framework.TestSuite;
17
18	public class LinkedListTest extends JSR166TestCase {
19	public static void main(String[] args) {
20	main(suite(), args);
21	}
22
23	public static Test suite() {
24	return new TestSuite(LinkedListTest.class);
25	}
26
27	/**
28	* Returns a new queue of given size containing consecutive
29	* Integers 0 ... n.
30	*/
31	private LinkedList<Integer> populatedQueue(int n) {
32	LinkedList<Integer> q = new LinkedList<Integer>();
33	assertTrue(q.isEmpty());
34	for (int i = 0; i < n; ++i)
35	assertTrue(q.offer(new Integer(i)));
36	assertFalse(q.isEmpty());
37	assertEquals(n, q.size());
38	return q;
39	}
40
41	/**
42	* new queue is empty
43	*/
44	public void testConstructor1() {
45	assertEquals(0, new LinkedList().size());
46	}
47
48	/**
49	* Initializing from null Collection throws NPE
50	*/
51	public void testConstructor3() {
52	try {
53	new LinkedList((Collection)null);
54	shouldThrow();
55	} catch (NullPointerException success) {}
56	}
57
58	/**
59	* Queue contains all elements of collection used to initialize
60	*/
61	public void testConstructor6() {
62	Integer[] ints = new Integer[SIZE];
63	for (int i = 0; i < SIZE; ++i)
64	ints[i] = i;
65	LinkedList q = new LinkedList(Arrays.asList(ints));
66	for (int i = 0; i < SIZE; ++i)
67	assertEquals(ints[i], q.poll());
68	}
69
70	/**
71	* isEmpty is true before add, false after
72	*/
73	public void testEmpty() {
74	LinkedList q = new LinkedList();
75	assertTrue(q.isEmpty());
76	q.add(new Integer(1));
77	assertFalse(q.isEmpty());
78	q.add(new Integer(2));
79	q.remove();
80	q.remove();
81	assertTrue(q.isEmpty());
82	}
83
84	/**
85	* size changes when elements added and removed
86	*/
87	public void testSize() {
88	LinkedList q = populatedQueue(SIZE);
89	for (int i = 0; i < SIZE; ++i) {
90	assertEquals(SIZE-i, q.size());
91	q.remove();
92	}
93	for (int i = 0; i < SIZE; ++i) {
94	assertEquals(i, q.size());
95	q.add(new Integer(i));
96	}
97	}
98
99	/**
100	* offer(null) succeeds
101	*/
102	public void testOfferNull() {
103	LinkedList q = new LinkedList();
104	q.offer(null);
105	}
106
107	/**
108	* Offer succeeds
109	*/
110	public void testOffer() {
111	LinkedList q = new LinkedList();
112	assertTrue(q.offer(new Integer(0)));
113	assertTrue(q.offer(new Integer(1)));
114	}
115
116	/**
117	* add succeeds
118	*/
119	public void testAdd() {
120	LinkedList q = new LinkedList();
121	for (int i = 0; i < SIZE; ++i) {
122	assertEquals(i, q.size());
123	assertTrue(q.add(new Integer(i)));
124	}
125	}
126
127	/**
128	* addAll(null) throws NPE
129	*/
130	public void testAddAll1() {
131	try {
132	LinkedList q = new LinkedList();
133	q.addAll(null);
134	shouldThrow();
135	} catch (NullPointerException success) {}
136	}
137
138	/**
139	* Queue contains all elements, in traversal order, of successful addAll
140	*/
141	public void testAddAll5() {
142	Integer[] empty = new Integer[0];
143	Integer[] ints = new Integer[SIZE];
144	for (int i = 0; i < SIZE; ++i)
145	ints[i] = i;
146	LinkedList q = new LinkedList();
147	assertFalse(q.addAll(Arrays.asList(empty)));
148	assertTrue(q.addAll(Arrays.asList(ints)));
149	for (int i = 0; i < SIZE; ++i)
150	assertEquals(ints[i], q.poll());
151	}
152
153	/**
154	* addAll with too large an index throws IOOBE
155	*/
156	public void testAddAll2_IndexOutOfBoundsException() {
157	LinkedList l = new LinkedList();
158	l.add(new Object());
159	LinkedList m = new LinkedList();
160	m.add(new Object());
161	try {
162	l.addAll(4,m);
163	shouldThrow();
164	} catch (IndexOutOfBoundsException success) {}
165	}
166
167	/**
168	* addAll with negative index throws IOOBE
169	*/
170	public void testAddAll4_BadIndex() {
171	LinkedList l = new LinkedList();
172	l.add(new Object());
173	LinkedList m = new LinkedList();
174	m.add(new Object());
175	try {
176	l.addAll(-1,m);
177	shouldThrow();
178	} catch (IndexOutOfBoundsException success) {}
179	}
180
181	/**
182	* poll succeeds unless empty
183	*/
184	public void testPoll() {
185	LinkedList q = populatedQueue(SIZE);
186	for (int i = 0; i < SIZE; ++i) {
187	assertEquals(i, q.poll());
188	}
189	assertNull(q.poll());
190	}
191
192	/**
193	* peek returns next element, or null if empty
194	*/
195	public void testPeek() {
196	LinkedList q = populatedQueue(SIZE);
197	for (int i = 0; i < SIZE; ++i) {
198	assertEquals(i, q.peek());
199	assertEquals(i, q.poll());
200	assertTrue(q.peek() == null \|\|
201	!q.peek().equals(i));
202	}
203	assertNull(q.peek());
204	}
205
206	/**
207	* element returns next element, or throws NSEE if empty
208	*/
209	public void testElement() {
210	LinkedList q = populatedQueue(SIZE);
211	for (int i = 0; i < SIZE; ++i) {
212	assertEquals(i, q.element());
213	assertEquals(i, q.poll());
214	}
215	try {
216	q.element();
217	shouldThrow();
218	} catch (NoSuchElementException success) {}
219	}
220
221	/**
222	* remove removes next element, or throws NSEE if empty
223	*/
224	public void testRemove() {
225	LinkedList q = populatedQueue(SIZE);
226	for (int i = 0; i < SIZE; ++i) {
227	assertEquals(i, q.remove());
228	}
229	try {
230	q.remove();
231	shouldThrow();
232	} catch (NoSuchElementException success) {}
233	}
234
235	/**
236	* remove(x) removes x and returns true if present
237	*/
238	public void testRemoveElement() {
239	LinkedList q = populatedQueue(SIZE);
240	for (int i = 1; i < SIZE; i += 2) {
241	assertTrue(q.contains(i));
242	assertTrue(q.remove((Integer)i));
243	assertFalse(q.contains(i));
244	assertTrue(q.contains(i-1));
245	}
246	for (int i = 0; i < SIZE; i += 2) {
247	assertTrue(q.contains(i));
248	assertTrue(q.remove((Integer)i));
249	assertFalse(q.contains(i));
250	assertFalse(q.remove((Integer)(i+1)));
251	assertFalse(q.contains(i+1));
252	}
253	assertTrue(q.isEmpty());
254	}
255
256	/**
257	* contains(x) reports true when elements added but not yet removed
258	*/
259	public void testContains() {
260	LinkedList q = populatedQueue(SIZE);
261	for (int i = 0; i < SIZE; ++i) {
262	assertTrue(q.contains(new Integer(i)));
263	q.poll();
264	assertFalse(q.contains(new Integer(i)));
265	}
266	}
267
268	/**
269	* clear removes all elements
270	*/
271	public void testClear() {
272	LinkedList q = populatedQueue(SIZE);
273	q.clear();
274	assertTrue(q.isEmpty());
275	assertEquals(0, q.size());
276	assertTrue(q.add(new Integer(1)));
277	assertFalse(q.isEmpty());
278	q.clear();
279	assertTrue(q.isEmpty());
280	}
281
282	/**
283	* containsAll(c) is true when c contains a subset of elements
284	*/
285	public void testContainsAll() {
286	LinkedList q = populatedQueue(SIZE);
287	LinkedList p = new LinkedList();
288	for (int i = 0; i < SIZE; ++i) {
289	assertTrue(q.containsAll(p));
290	assertFalse(p.containsAll(q));
291	assertTrue(p.add(new Integer(i)));
292	}
293	assertTrue(p.containsAll(q));
294	}
295
296	/**
297	* retainAll(c) retains only those elements of c and reports true if changed
298	*/
299	public void testRetainAll() {
300	LinkedList q = populatedQueue(SIZE);
301	LinkedList p = populatedQueue(SIZE);
302	for (int i = 0; i < SIZE; ++i) {
303	boolean changed = q.retainAll(p);
304	if (i == 0)
305	assertFalse(changed);
306	else
307	assertTrue(changed);
308
309	assertTrue(q.containsAll(p));
310	assertEquals(SIZE-i, q.size());
311	p.remove();
312	}
313	}
314
315	/**
316	* removeAll(c) removes only those elements of c and reports true if changed
317	*/
318	public void testRemoveAll() {
319	for (int i = 1; i < SIZE; ++i) {
320	LinkedList q = populatedQueue(SIZE);
321	LinkedList p = populatedQueue(i);
322	assertTrue(q.removeAll(p));
323	assertEquals(SIZE-i, q.size());
324	for (int j = 0; j < i; ++j) {
325	Integer x = (Integer)(p.remove());
326	assertFalse(q.contains(x));
327	}
328	}
329	}
330
331	/**
332	* toArray contains all elements in FIFO order
333	*/
334	public void testToArray() {
335	LinkedList q = populatedQueue(SIZE);
336	Object[] o = q.toArray();
337	for (int i = 0; i < o.length; i++)
338	assertSame(o[i], q.poll());
339	}
340
341	/**
342	* toArray(a) contains all elements in FIFO order
343	*/
344	public void testToArray2() {
345	LinkedList<Integer> q = populatedQueue(SIZE);
346	Integer[] ints = new Integer[SIZE];
347	Integer[] array = q.toArray(ints);
348	assertSame(ints, array);
349	for (int i = 0; i < ints.length; i++)
350	assertSame(ints[i], q.poll());
351	}
352
353	/**
354	* toArray(null) throws NullPointerException
355	*/
356	public void testToArray_NullArg() {
357	LinkedList l = new LinkedList();
358	l.add(new Object());
359	try {
360	l.toArray(null);
361	shouldThrow();
362	} catch (NullPointerException success) {}
363	}
364
365	/**
366	* toArray(incompatible array type) throws ArrayStoreException
367	*/
368	public void testToArray1_BadArg() {
369	LinkedList l = new LinkedList();
370	l.add(new Integer(5));
371	try {
372	l.toArray(new String[10]);
373	shouldThrow();
374	} catch (ArrayStoreException success) {}
375	}
376
377	/**
378	* iterator iterates through all elements
379	*/
380	public void testIterator() {
381	LinkedList q = populatedQueue(SIZE);
382	Iterator it = q.iterator();
383	int i;
384	for (i = 0; it.hasNext(); i++)
385	assertTrue(q.contains(it.next()));
386	assertEquals(i, SIZE);
387	assertIteratorExhausted(it);
388	}
389
390	/**
391	* iterator of empty collection has no elements
392	*/
393	public void testEmptyIterator() {
394	assertIteratorExhausted(new LinkedList().iterator());
395	}
396
397	/**
398	* iterator ordering is FIFO
399	*/
400	public void testIteratorOrdering() {
401	final LinkedList q = new LinkedList();
402	q.add(new Integer(1));
403	q.add(new Integer(2));
404	q.add(new Integer(3));
405	int k = 0;
406	for (Iterator it = q.iterator(); it.hasNext();) {
407	assertEquals(++k, it.next());
408	}
409
410	assertEquals(3, k);
411	}
412
413	/**
414	* iterator.remove removes current element
415	*/
416	public void testIteratorRemove() {
417	final LinkedList q = new LinkedList();
418	q.add(new Integer(1));
419	q.add(new Integer(2));
420	q.add(new Integer(3));
421	Iterator it = q.iterator();
422	assertEquals(1, it.next());
423	it.remove();
424	it = q.iterator();
425	assertEquals(2, it.next());
426	assertEquals(3, it.next());
427	assertFalse(it.hasNext());
428	}
429
430	/**
431	* Descending iterator iterates through all elements
432	*/
433	public void testDescendingIterator() {
434	LinkedList q = populatedQueue(SIZE);
435	int i = 0;
436	Iterator it = q.descendingIterator();
437	while (it.hasNext()) {
438	assertTrue(q.contains(it.next()));
439	++i;
440	}
441	assertEquals(i, SIZE);
442	assertFalse(it.hasNext());
443	try {
444	it.next();
445	shouldThrow();
446	} catch (NoSuchElementException success) {}
447	}
448
449	/**
450	* Descending iterator ordering is reverse FIFO
451	*/
452	public void testDescendingIteratorOrdering() {
453	final LinkedList q = new LinkedList();
454	q.add(new Integer(3));
455	q.add(new Integer(2));
456	q.add(new Integer(1));
457	int k = 0;
458	for (Iterator it = q.descendingIterator(); it.hasNext();) {
459	assertEquals(++k, it.next());
460	}
461
462	assertEquals(3, k);
463	}
464
465	/**
466	* descendingIterator.remove removes current element
467	*/
468	public void testDescendingIteratorRemove() {
469	final LinkedList q = new LinkedList();
470	q.add(three);
471	q.add(two);
472	q.add(one);
473	Iterator it = q.descendingIterator();
474	it.next();
475	it.remove();
476	it = q.descendingIterator();
477	assertSame(it.next(), two);
478	assertSame(it.next(), three);
479	assertFalse(it.hasNext());
480	}
481
482	/**
483	* toString contains toStrings of elements
484	*/
485	public void testToString() {
486	LinkedList q = populatedQueue(SIZE);
487	String s = q.toString();
488	for (int i = 0; i < SIZE; ++i) {
489	assertTrue(s.contains(String.valueOf(i)));
490	}
491	}
492
493	/**
494	* peek returns element inserted with addFirst
495	*/
496	public void testAddFirst() {
497	LinkedList q = populatedQueue(3);
498	q.addFirst(four);
499	assertSame(four, q.peek());
500	}
501
502	/**
503	* peekFirst returns element inserted with push
504	*/
505	public void testPush() {
506	LinkedList q = populatedQueue(3);
507	q.push(four);
508	assertSame(four, q.peekFirst());
509	}
510
511	/**
512	* pop removes next element, or throws NSEE if empty
513	*/
514	public void testPop() {
515	LinkedList q = populatedQueue(SIZE);
516	for (int i = 0; i < SIZE; ++i) {
517	assertEquals(i, q.pop());
518	}
519	try {
520	q.pop();
521	shouldThrow();
522	} catch (NoSuchElementException success) {}
523	}
524
525	/**
526	* OfferFirst succeeds
527	*/
528	public void testOfferFirst() {
529	LinkedList q = new LinkedList();
530	assertTrue(q.offerFirst(new Integer(0)));
531	assertTrue(q.offerFirst(new Integer(1)));
532	}
533
534	/**
535	* OfferLast succeeds
536	*/
537	public void testOfferLast() {
538	LinkedList q = new LinkedList();
539	assertTrue(q.offerLast(new Integer(0)));
540	assertTrue(q.offerLast(new Integer(1)));
541	}
542
543	/**
544	* pollLast succeeds unless empty
545	*/
546	public void testPollLast() {
547	LinkedList q = populatedQueue(SIZE);
548	for (int i = SIZE-1; i >= 0; --i) {
549	assertEquals(i, q.pollLast());
550	}
551	assertNull(q.pollLast());
552	}
553
554	/**
555	* peekFirst returns next element, or null if empty
556	*/
557	public void testPeekFirst() {
558	LinkedList q = populatedQueue(SIZE);
559	for (int i = 0; i < SIZE; ++i) {
560	assertEquals(i, q.peekFirst());
561	assertEquals(i, q.pollFirst());
562	assertTrue(q.peekFirst() == null \|\|
563	!q.peekFirst().equals(i));
564	}
565	assertNull(q.peekFirst());
566	}
567
568	/**
569	* peekLast returns next element, or null if empty
570	*/
571	public void testPeekLast() {
572	LinkedList q = populatedQueue(SIZE);
573	for (int i = SIZE-1; i >= 0; --i) {
574	assertEquals(i, q.peekLast());
575	assertEquals(i, q.pollLast());
576	assertTrue(q.peekLast() == null \|\|
577	!q.peekLast().equals(i));
578	}
579	assertNull(q.peekLast());
580	}
581
582	public void testFirstElement() {
583	LinkedList q = populatedQueue(SIZE);
584	for (int i = 0; i < SIZE; ++i) {
585	assertEquals(i, q.getFirst());
586	assertEquals(i, q.pollFirst());
587	}
588	try {
589	q.getFirst();
590	shouldThrow();
591	} catch (NoSuchElementException success) {}
592	}
593
594	/**
595	* getLast returns next element, or throws NSEE if empty
596	*/
597	public void testLastElement() {
598	LinkedList q = populatedQueue(SIZE);
599	for (int i = SIZE-1; i >= 0; --i) {
600	assertEquals(i, q.getLast());
601	assertEquals(i, q.pollLast());
602	}
603	try {
604	q.getLast();
605	shouldThrow();
606	} catch (NoSuchElementException success) {}
607	assertNull(q.peekLast());
608	}
609
610	/**
611	* removeFirstOccurrence(x) removes x and returns true if present
612	*/
613	public void testRemoveFirstOccurrence() {
614	LinkedList q = populatedQueue(SIZE);
615	for (int i = 1; i < SIZE; i += 2) {
616	assertTrue(q.removeFirstOccurrence(new Integer(i)));
617	}
618	for (int i = 0; i < SIZE; i += 2) {
619	assertTrue(q.removeFirstOccurrence(new Integer(i)));
620	assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
621	}
622	assertTrue(q.isEmpty());
623	}
624
625	/**
626	* removeLastOccurrence(x) removes x and returns true if present
627	*/
628	public void testRemoveLastOccurrence() {
629	LinkedList q = populatedQueue(SIZE);
630	for (int i = 1; i < SIZE; i += 2) {
631	assertTrue(q.removeLastOccurrence(new Integer(i)));
632	}
633	for (int i = 0; i < SIZE; i += 2) {
634	assertTrue(q.removeLastOccurrence(new Integer(i)));
635	assertFalse(q.removeLastOccurrence(new Integer(i+1)));
636	}
637	assertTrue(q.isEmpty());
638	}
639
640	}