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) {
        junit.textui.TestRunner.run(suite());
    }

    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 {
            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 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);
        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(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:	1.34
Committed:	Wed Dec 31 20:17:39 2014 UTC (9 years, 4 months ago) by jsr166
Branch:	MAIN
Changes since 1.33:	+2 -2 lines
Log Message:	coding style
#	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	junit.textui.TestRunner.run(suite());
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	LinkedList q = 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	int i = 0;
383	Iterator it = q.iterator();
384	while (it.hasNext()) {
385	assertTrue(q.contains(it.next()));
386	++i;
387	}
388	assertEquals(i, SIZE);
389	}
390
391	/**
392	* iterator ordering is FIFO
393	*/
394	public void testIteratorOrdering() {
395	final LinkedList q = new LinkedList();
396	q.add(new Integer(1));
397	q.add(new Integer(2));
398	q.add(new Integer(3));
399	int k = 0;
400	for (Iterator it = q.iterator(); it.hasNext();) {
401	assertEquals(++k, it.next());
402	}
403
404	assertEquals(3, k);
405	}
406
407	/**
408	* iterator.remove removes current element
409	*/
410	public void testIteratorRemove() {
411	final LinkedList q = new LinkedList();
412	q.add(new Integer(1));
413	q.add(new Integer(2));
414	q.add(new Integer(3));
415	Iterator it = q.iterator();
416	assertEquals(1, it.next());
417	it.remove();
418	it = q.iterator();
419	assertEquals(2, it.next());
420	assertEquals(3, it.next());
421	assertFalse(it.hasNext());
422	}
423
424	/**
425	* Descending iterator iterates through all elements
426	*/
427	public void testDescendingIterator() {
428	LinkedList q = populatedQueue(SIZE);
429	int i = 0;
430	Iterator it = q.descendingIterator();
431	while (it.hasNext()) {
432	assertTrue(q.contains(it.next()));
433	++i;
434	}
435	assertEquals(i, SIZE);
436	assertFalse(it.hasNext());
437	try {
438	it.next();
439	shouldThrow();
440	} catch (NoSuchElementException success) {}
441	}
442
443	/**
444	* Descending iterator ordering is reverse FIFO
445	*/
446	public void testDescendingIteratorOrdering() {
447	final LinkedList q = new LinkedList();
448	q.add(new Integer(3));
449	q.add(new Integer(2));
450	q.add(new Integer(1));
451	int k = 0;
452	for (Iterator it = q.descendingIterator(); it.hasNext();) {
453	assertEquals(++k, it.next());
454	}
455
456	assertEquals(3, k);
457	}
458
459	/**
460	* descendingIterator.remove removes current element
461	*/
462	public void testDescendingIteratorRemove() {
463	final LinkedList q = new LinkedList();
464	q.add(three);
465	q.add(two);
466	q.add(one);
467	Iterator it = q.descendingIterator();
468	it.next();
469	it.remove();
470	it = q.descendingIterator();
471	assertSame(it.next(), two);
472	assertSame(it.next(), three);
473	assertFalse(it.hasNext());
474	}
475
476	/**
477	* toString contains toStrings of elements
478	*/
479	public void testToString() {
480	LinkedList q = populatedQueue(SIZE);
481	String s = q.toString();
482	for (int i = 0; i < SIZE; ++i) {
483	assertTrue(s.contains(String.valueOf(i)));
484	}
485	}
486
487	/**
488	* peek returns element inserted with addFirst
489	*/
490	public void testAddFirst() {
491	LinkedList q = populatedQueue(3);
492	q.addFirst(four);
493	assertSame(four, q.peek());
494	}
495
496	/**
497	* peekFirst returns element inserted with push
498	*/
499	public void testPush() {
500	LinkedList q = populatedQueue(3);
501	q.push(four);
502	assertSame(four, q.peekFirst());
503	}
504
505	/**
506	* pop removes next element, or throws NSEE if empty
507	*/
508	public void testPop() {
509	LinkedList q = populatedQueue(SIZE);
510	for (int i = 0; i < SIZE; ++i) {
511	assertEquals(i, q.pop());
512	}
513	try {
514	q.pop();
515	shouldThrow();
516	} catch (NoSuchElementException success) {}
517	}
518
519	/**
520	* OfferFirst succeeds
521	*/
522	public void testOfferFirst() {
523	LinkedList q = new LinkedList();
524	assertTrue(q.offerFirst(new Integer(0)));
525	assertTrue(q.offerFirst(new Integer(1)));
526	}
527
528	/**
529	* OfferLast succeeds
530	*/
531	public void testOfferLast() {
532	LinkedList q = new LinkedList();
533	assertTrue(q.offerLast(new Integer(0)));
534	assertTrue(q.offerLast(new Integer(1)));
535	}
536
537	/**
538	* pollLast succeeds unless empty
539	*/
540	public void testPollLast() {
541	LinkedList q = populatedQueue(SIZE);
542	for (int i = SIZE-1; i >= 0; --i) {
543	assertEquals(i, q.pollLast());
544	}
545	assertNull(q.pollLast());
546	}
547
548	/**
549	* peekFirst returns next element, or null if empty
550	*/
551	public void testPeekFirst() {
552	LinkedList q = populatedQueue(SIZE);
553	for (int i = 0; i < SIZE; ++i) {
554	assertEquals(i, q.peekFirst());
555	assertEquals(i, q.pollFirst());
556	assertTrue(q.peekFirst() == null \|\|
557	!q.peekFirst().equals(i));
558	}
559	assertNull(q.peekFirst());
560	}
561
562	/**
563	* peekLast returns next element, or null if empty
564	*/
565	public void testPeekLast() {
566	LinkedList q = populatedQueue(SIZE);
567	for (int i = SIZE-1; i >= 0; --i) {
568	assertEquals(i, q.peekLast());
569	assertEquals(i, q.pollLast());
570	assertTrue(q.peekLast() == null \|\|
571	!q.peekLast().equals(i));
572	}
573	assertNull(q.peekLast());
574	}
575
576	public void testFirstElement() {
577	LinkedList q = populatedQueue(SIZE);
578	for (int i = 0; i < SIZE; ++i) {
579	assertEquals(i, q.getFirst());
580	assertEquals(i, q.pollFirst());
581	}
582	try {
583	q.getFirst();
584	shouldThrow();
585	} catch (NoSuchElementException success) {}
586	}
587
588	/**
589	* getLast returns next element, or throws NSEE if empty
590	*/
591	public void testLastElement() {
592	LinkedList q = populatedQueue(SIZE);
593	for (int i = SIZE-1; i >= 0; --i) {
594	assertEquals(i, q.getLast());
595	assertEquals(i, q.pollLast());
596	}
597	try {
598	q.getLast();
599	shouldThrow();
600	} catch (NoSuchElementException success) {}
601	assertNull(q.peekLast());
602	}
603
604	/**
605	* removeFirstOccurrence(x) removes x and returns true if present
606	*/
607	public void testRemoveFirstOccurrence() {
608	LinkedList q = populatedQueue(SIZE);
609	for (int i = 1; i < SIZE; i += 2) {
610	assertTrue(q.removeFirstOccurrence(new Integer(i)));
611	}
612	for (int i = 0; i < SIZE; i += 2) {
613	assertTrue(q.removeFirstOccurrence(new Integer(i)));
614	assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
615	}
616	assertTrue(q.isEmpty());
617	}
618
619	/**
620	* removeLastOccurrence(x) removes x and returns true if present
621	*/
622	public void testRemoveLastOccurrence() {
623	LinkedList q = populatedQueue(SIZE);
624	for (int i = 1; i < SIZE; i += 2) {
625	assertTrue(q.removeLastOccurrence(new Integer(i)));
626	}
627	for (int i = 0; i < SIZE; i += 2) {
628	assertTrue(q.removeLastOccurrence(new Integer(i)));
629	assertFalse(q.removeLastOccurrence(new Integer(i+1)));
630	}
631	assertTrue(q.isEmpty());
632	}
633
634	}