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() {
        class Implementation implements CollectionImplementation {
            public Class<?> klazz() { return LinkedList.class; }
            public Collection emptyCollection() { return new LinkedList(); }
            public Object makeElement(int i) { return i; }
            public boolean isConcurrent() { return false; }
            public boolean permitsNulls() { return true; }
        }
        class SubListImplementation extends Implementation {
            public Collection emptyCollection() {
                return new LinkedList().subList(0, 0);
            }
        }
        return newTestSuite(
                LinkedListTest.class,
                CollectionTest.testSuite(new Implementation()),
                CollectionTest.testSuite(new SubListImplementation()));
    }

    /**
     * Returns a new queue of given size containing consecutive
     * Integers 0 ... n - 1.
     */
    private LinkedList<Integer> populatedQueue(int n) {
        LinkedList<Integer> q = new LinkedList<>();
        assertTrue(q.isEmpty());
        for (int i = 0; i < n; ++i)
            assertTrue(q.offer(new Integer(i)));
        assertFalse(q.isEmpty());
        assertEquals(n, q.size());
        assertEquals((Integer) 0, q.peekFirst());
        assertEquals((Integer) (n - 1), q.peekLast());
        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);
        assertNull(q.get(0));
        assertTrue(q.contains(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() {
        LinkedList q = new LinkedList();
        try {
            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:	1.44
Committed:	Wed Jan 4 06:09:58 2017 UTC (7 years, 4 months ago) by jsr166
Branch:	MAIN
Changes since 1.43:	+1 -1 lines
Log Message:	convert to Diamond
#	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	class Implementation implements CollectionImplementation {
25	public Class<?> klazz() { return LinkedList.class; }
26	public Collection emptyCollection() { return new LinkedList(); }
27	public Object makeElement(int i) { return i; }
28	public boolean isConcurrent() { return false; }
29	public boolean permitsNulls() { return true; }
30	}
31	class SubListImplementation extends Implementation {
32	public Collection emptyCollection() {
33	return new LinkedList().subList(0, 0);
34	}
35	}
36	return newTestSuite(
37	LinkedListTest.class,
38	CollectionTest.testSuite(new Implementation()),
39	CollectionTest.testSuite(new SubListImplementation()));
40	}
41
42	/**
43	* Returns a new queue of given size containing consecutive
44	* Integers 0 ... n - 1.
45	*/
46	private LinkedList<Integer> populatedQueue(int n) {
47	LinkedList<Integer> q = new LinkedList<>();
48	assertTrue(q.isEmpty());
49	for (int i = 0; i < n; ++i)
50	assertTrue(q.offer(new Integer(i)));
51	assertFalse(q.isEmpty());
52	assertEquals(n, q.size());
53	assertEquals((Integer) 0, q.peekFirst());
54	assertEquals((Integer) (n - 1), q.peekLast());
55	return q;
56	}
57
58	/**
59	* new queue is empty
60	*/
61	public void testConstructor1() {
62	assertEquals(0, new LinkedList().size());
63	}
64
65	/**
66	* Initializing from null Collection throws NPE
67	*/
68	public void testConstructor3() {
69	try {
70	new LinkedList((Collection)null);
71	shouldThrow();
72	} catch (NullPointerException success) {}
73	}
74
75	/**
76	* Queue contains all elements of collection used to initialize
77	*/
78	public void testConstructor6() {
79	Integer[] ints = new Integer[SIZE];
80	for (int i = 0; i < SIZE; ++i)
81	ints[i] = i;
82	LinkedList q = new LinkedList(Arrays.asList(ints));
83	for (int i = 0; i < SIZE; ++i)
84	assertEquals(ints[i], q.poll());
85	}
86
87	/**
88	* isEmpty is true before add, false after
89	*/
90	public void testEmpty() {
91	LinkedList q = new LinkedList();
92	assertTrue(q.isEmpty());
93	q.add(new Integer(1));
94	assertFalse(q.isEmpty());
95	q.add(new Integer(2));
96	q.remove();
97	q.remove();
98	assertTrue(q.isEmpty());
99	}
100
101	/**
102	* size changes when elements added and removed
103	*/
104	public void testSize() {
105	LinkedList q = populatedQueue(SIZE);
106	for (int i = 0; i < SIZE; ++i) {
107	assertEquals(SIZE - i, q.size());
108	q.remove();
109	}
110	for (int i = 0; i < SIZE; ++i) {
111	assertEquals(i, q.size());
112	q.add(new Integer(i));
113	}
114	}
115
116	/**
117	* offer(null) succeeds
118	*/
119	public void testOfferNull() {
120	LinkedList q = new LinkedList();
121	q.offer(null);
122	assertNull(q.get(0));
123	assertTrue(q.contains(null));
124	}
125
126	/**
127	* Offer succeeds
128	*/
129	public void testOffer() {
130	LinkedList q = new LinkedList();
131	assertTrue(q.offer(new Integer(0)));
132	assertTrue(q.offer(new Integer(1)));
133	}
134
135	/**
136	* add succeeds
137	*/
138	public void testAdd() {
139	LinkedList q = new LinkedList();
140	for (int i = 0; i < SIZE; ++i) {
141	assertEquals(i, q.size());
142	assertTrue(q.add(new Integer(i)));
143	}
144	}
145
146	/**
147	* addAll(null) throws NPE
148	*/
149	public void testAddAll1() {
150	LinkedList q = new LinkedList();
151	try {
152	q.addAll(null);
153	shouldThrow();
154	} catch (NullPointerException success) {}
155	}
156
157	/**
158	* Queue contains all elements, in traversal order, of successful addAll
159	*/
160	public void testAddAll5() {
161	Integer[] empty = new Integer[0];
162	Integer[] ints = new Integer[SIZE];
163	for (int i = 0; i < SIZE; ++i)
164	ints[i] = i;
165	LinkedList q = new LinkedList();
166	assertFalse(q.addAll(Arrays.asList(empty)));
167	assertTrue(q.addAll(Arrays.asList(ints)));
168	for (int i = 0; i < SIZE; ++i)
169	assertEquals(ints[i], q.poll());
170	}
171
172	/**
173	* addAll with too large an index throws IOOBE
174	*/
175	public void testAddAll2_IndexOutOfBoundsException() {
176	LinkedList l = new LinkedList();
177	l.add(new Object());
178	LinkedList m = new LinkedList();
179	m.add(new Object());
180	try {
181	l.addAll(4,m);
182	shouldThrow();
183	} catch (IndexOutOfBoundsException success) {}
184	}
185
186	/**
187	* addAll with negative index throws IOOBE
188	*/
189	public void testAddAll4_BadIndex() {
190	LinkedList l = new LinkedList();
191	l.add(new Object());
192	LinkedList m = new LinkedList();
193	m.add(new Object());
194	try {
195	l.addAll(-1,m);
196	shouldThrow();
197	} catch (IndexOutOfBoundsException success) {}
198	}
199
200	/**
201	* poll succeeds unless empty
202	*/
203	public void testPoll() {
204	LinkedList q = populatedQueue(SIZE);
205	for (int i = 0; i < SIZE; ++i) {
206	assertEquals(i, q.poll());
207	}
208	assertNull(q.poll());
209	}
210
211	/**
212	* peek returns next element, or null if empty
213	*/
214	public void testPeek() {
215	LinkedList q = populatedQueue(SIZE);
216	for (int i = 0; i < SIZE; ++i) {
217	assertEquals(i, q.peek());
218	assertEquals(i, q.poll());
219	assertTrue(q.peek() == null \|\|
220	!q.peek().equals(i));
221	}
222	assertNull(q.peek());
223	}
224
225	/**
226	* element returns next element, or throws NSEE if empty
227	*/
228	public void testElement() {
229	LinkedList q = populatedQueue(SIZE);
230	for (int i = 0; i < SIZE; ++i) {
231	assertEquals(i, q.element());
232	assertEquals(i, q.poll());
233	}
234	try {
235	q.element();
236	shouldThrow();
237	} catch (NoSuchElementException success) {}
238	}
239
240	/**
241	* remove removes next element, or throws NSEE if empty
242	*/
243	public void testRemove() {
244	LinkedList q = populatedQueue(SIZE);
245	for (int i = 0; i < SIZE; ++i) {
246	assertEquals(i, q.remove());
247	}
248	try {
249	q.remove();
250	shouldThrow();
251	} catch (NoSuchElementException success) {}
252	}
253
254	/**
255	* remove(x) removes x and returns true if present
256	*/
257	public void testRemoveElement() {
258	LinkedList q = populatedQueue(SIZE);
259	for (int i = 1; i < SIZE; i += 2) {
260	assertTrue(q.contains(i));
261	assertTrue(q.remove((Integer)i));
262	assertFalse(q.contains(i));
263	assertTrue(q.contains(i - 1));
264	}
265	for (int i = 0; i < SIZE; i += 2) {
266	assertTrue(q.contains(i));
267	assertTrue(q.remove((Integer)i));
268	assertFalse(q.contains(i));
269	assertFalse(q.remove((Integer)(i + 1)));
270	assertFalse(q.contains(i + 1));
271	}
272	assertTrue(q.isEmpty());
273	}
274
275	/**
276	* contains(x) reports true when elements added but not yet removed
277	*/
278	public void testContains() {
279	LinkedList q = populatedQueue(SIZE);
280	for (int i = 0; i < SIZE; ++i) {
281	assertTrue(q.contains(new Integer(i)));
282	q.poll();
283	assertFalse(q.contains(new Integer(i)));
284	}
285	}
286
287	/**
288	* clear removes all elements
289	*/
290	public void testClear() {
291	LinkedList q = populatedQueue(SIZE);
292	q.clear();
293	assertTrue(q.isEmpty());
294	assertEquals(0, q.size());
295	assertTrue(q.add(new Integer(1)));
296	assertFalse(q.isEmpty());
297	q.clear();
298	assertTrue(q.isEmpty());
299	}
300
301	/**
302	* containsAll(c) is true when c contains a subset of elements
303	*/
304	public void testContainsAll() {
305	LinkedList q = populatedQueue(SIZE);
306	LinkedList p = new LinkedList();
307	for (int i = 0; i < SIZE; ++i) {
308	assertTrue(q.containsAll(p));
309	assertFalse(p.containsAll(q));
310	assertTrue(p.add(new Integer(i)));
311	}
312	assertTrue(p.containsAll(q));
313	}
314
315	/**
316	* retainAll(c) retains only those elements of c and reports true if changed
317	*/
318	public void testRetainAll() {
319	LinkedList q = populatedQueue(SIZE);
320	LinkedList p = populatedQueue(SIZE);
321	for (int i = 0; i < SIZE; ++i) {
322	boolean changed = q.retainAll(p);
323	if (i == 0)
324	assertFalse(changed);
325	else
326	assertTrue(changed);
327
328	assertTrue(q.containsAll(p));
329	assertEquals(SIZE - i, q.size());
330	p.remove();
331	}
332	}
333
334	/**
335	* removeAll(c) removes only those elements of c and reports true if changed
336	*/
337	public void testRemoveAll() {
338	for (int i = 1; i < SIZE; ++i) {
339	LinkedList q = populatedQueue(SIZE);
340	LinkedList p = populatedQueue(i);
341	assertTrue(q.removeAll(p));
342	assertEquals(SIZE - i, q.size());
343	for (int j = 0; j < i; ++j) {
344	Integer x = (Integer)(p.remove());
345	assertFalse(q.contains(x));
346	}
347	}
348	}
349
350	/**
351	* toArray contains all elements in FIFO order
352	*/
353	public void testToArray() {
354	LinkedList q = populatedQueue(SIZE);
355	Object[] o = q.toArray();
356	for (int i = 0; i < o.length; i++)
357	assertSame(o[i], q.poll());
358	}
359
360	/**
361	* toArray(a) contains all elements in FIFO order
362	*/
363	public void testToArray2() {
364	LinkedList<Integer> q = populatedQueue(SIZE);
365	Integer[] ints = new Integer[SIZE];
366	Integer[] array = q.toArray(ints);
367	assertSame(ints, array);
368	for (int i = 0; i < ints.length; i++)
369	assertSame(ints[i], q.poll());
370	}
371
372	/**
373	* toArray(null) throws NullPointerException
374	*/
375	public void testToArray_NullArg() {
376	LinkedList l = new LinkedList();
377	l.add(new Object());
378	try {
379	l.toArray(null);
380	shouldThrow();
381	} catch (NullPointerException success) {}
382	}
383
384	/**
385	* toArray(incompatible array type) throws ArrayStoreException
386	*/
387	public void testToArray1_BadArg() {
388	LinkedList l = new LinkedList();
389	l.add(new Integer(5));
390	try {
391	l.toArray(new String[10]);
392	shouldThrow();
393	} catch (ArrayStoreException success) {}
394	}
395
396	/**
397	* iterator iterates through all elements
398	*/
399	public void testIterator() {
400	LinkedList q = populatedQueue(SIZE);
401	Iterator it = q.iterator();
402	int i;
403	for (i = 0; it.hasNext(); i++)
404	assertTrue(q.contains(it.next()));
405	assertEquals(i, SIZE);
406	assertIteratorExhausted(it);
407	}
408
409	/**
410	* iterator of empty collection has no elements
411	*/
412	public void testEmptyIterator() {
413	assertIteratorExhausted(new LinkedList().iterator());
414	}
415
416	/**
417	* iterator ordering is FIFO
418	*/
419	public void testIteratorOrdering() {
420	final LinkedList q = new LinkedList();
421	q.add(new Integer(1));
422	q.add(new Integer(2));
423	q.add(new Integer(3));
424	int k = 0;
425	for (Iterator it = q.iterator(); it.hasNext();) {
426	assertEquals(++k, it.next());
427	}
428
429	assertEquals(3, k);
430	}
431
432	/**
433	* iterator.remove removes current element
434	*/
435	public void testIteratorRemove() {
436	final LinkedList q = new LinkedList();
437	q.add(new Integer(1));
438	q.add(new Integer(2));
439	q.add(new Integer(3));
440	Iterator it = q.iterator();
441	assertEquals(1, it.next());
442	it.remove();
443	it = q.iterator();
444	assertEquals(2, it.next());
445	assertEquals(3, it.next());
446	assertFalse(it.hasNext());
447	}
448
449	/**
450	* Descending iterator iterates through all elements
451	*/
452	public void testDescendingIterator() {
453	LinkedList q = populatedQueue(SIZE);
454	int i = 0;
455	Iterator it = q.descendingIterator();
456	while (it.hasNext()) {
457	assertTrue(q.contains(it.next()));
458	++i;
459	}
460	assertEquals(i, SIZE);
461	assertFalse(it.hasNext());
462	try {
463	it.next();
464	shouldThrow();
465	} catch (NoSuchElementException success) {}
466	}
467
468	/**
469	* Descending iterator ordering is reverse FIFO
470	*/
471	public void testDescendingIteratorOrdering() {
472	final LinkedList q = new LinkedList();
473	q.add(new Integer(3));
474	q.add(new Integer(2));
475	q.add(new Integer(1));
476	int k = 0;
477	for (Iterator it = q.descendingIterator(); it.hasNext();) {
478	assertEquals(++k, it.next());
479	}
480
481	assertEquals(3, k);
482	}
483
484	/**
485	* descendingIterator.remove removes current element
486	*/
487	public void testDescendingIteratorRemove() {
488	final LinkedList q = new LinkedList();
489	q.add(three);
490	q.add(two);
491	q.add(one);
492	Iterator it = q.descendingIterator();
493	it.next();
494	it.remove();
495	it = q.descendingIterator();
496	assertSame(it.next(), two);
497	assertSame(it.next(), three);
498	assertFalse(it.hasNext());
499	}
500
501	/**
502	* toString contains toStrings of elements
503	*/
504	public void testToString() {
505	LinkedList q = populatedQueue(SIZE);
506	String s = q.toString();
507	for (int i = 0; i < SIZE; ++i) {
508	assertTrue(s.contains(String.valueOf(i)));
509	}
510	}
511
512	/**
513	* peek returns element inserted with addFirst
514	*/
515	public void testAddFirst() {
516	LinkedList q = populatedQueue(3);
517	q.addFirst(four);
518	assertSame(four, q.peek());
519	}
520
521	/**
522	* peekFirst returns element inserted with push
523	*/
524	public void testPush() {
525	LinkedList q = populatedQueue(3);
526	q.push(four);
527	assertSame(four, q.peekFirst());
528	}
529
530	/**
531	* pop removes next element, or throws NSEE if empty
532	*/
533	public void testPop() {
534	LinkedList q = populatedQueue(SIZE);
535	for (int i = 0; i < SIZE; ++i) {
536	assertEquals(i, q.pop());
537	}
538	try {
539	q.pop();
540	shouldThrow();
541	} catch (NoSuchElementException success) {}
542	}
543
544	/**
545	* OfferFirst succeeds
546	*/
547	public void testOfferFirst() {
548	LinkedList q = new LinkedList();
549	assertTrue(q.offerFirst(new Integer(0)));
550	assertTrue(q.offerFirst(new Integer(1)));
551	}
552
553	/**
554	* OfferLast succeeds
555	*/
556	public void testOfferLast() {
557	LinkedList q = new LinkedList();
558	assertTrue(q.offerLast(new Integer(0)));
559	assertTrue(q.offerLast(new Integer(1)));
560	}
561
562	/**
563	* pollLast succeeds unless empty
564	*/
565	public void testPollLast() {
566	LinkedList q = populatedQueue(SIZE);
567	for (int i = SIZE - 1; i >= 0; --i) {
568	assertEquals(i, q.pollLast());
569	}
570	assertNull(q.pollLast());
571	}
572
573	/**
574	* peekFirst returns next element, or null if empty
575	*/
576	public void testPeekFirst() {
577	LinkedList q = populatedQueue(SIZE);
578	for (int i = 0; i < SIZE; ++i) {
579	assertEquals(i, q.peekFirst());
580	assertEquals(i, q.pollFirst());
581	assertTrue(q.peekFirst() == null \|\|
582	!q.peekFirst().equals(i));
583	}
584	assertNull(q.peekFirst());
585	}
586
587	/**
588	* peekLast returns next element, or null if empty
589	*/
590	public void testPeekLast() {
591	LinkedList q = populatedQueue(SIZE);
592	for (int i = SIZE - 1; i >= 0; --i) {
593	assertEquals(i, q.peekLast());
594	assertEquals(i, q.pollLast());
595	assertTrue(q.peekLast() == null \|\|
596	!q.peekLast().equals(i));
597	}
598	assertNull(q.peekLast());
599	}
600
601	public void testFirstElement() {
602	LinkedList q = populatedQueue(SIZE);
603	for (int i = 0; i < SIZE; ++i) {
604	assertEquals(i, q.getFirst());
605	assertEquals(i, q.pollFirst());
606	}
607	try {
608	q.getFirst();
609	shouldThrow();
610	} catch (NoSuchElementException success) {}
611	}
612
613	/**
614	* getLast returns next element, or throws NSEE if empty
615	*/
616	public void testLastElement() {
617	LinkedList q = populatedQueue(SIZE);
618	for (int i = SIZE - 1; i >= 0; --i) {
619	assertEquals(i, q.getLast());
620	assertEquals(i, q.pollLast());
621	}
622	try {
623	q.getLast();
624	shouldThrow();
625	} catch (NoSuchElementException success) {}
626	assertNull(q.peekLast());
627	}
628
629	/**
630	* removeFirstOccurrence(x) removes x and returns true if present
631	*/
632	public void testRemoveFirstOccurrence() {
633	LinkedList q = populatedQueue(SIZE);
634	for (int i = 1; i < SIZE; i += 2) {
635	assertTrue(q.removeFirstOccurrence(new Integer(i)));
636	}
637	for (int i = 0; i < SIZE; i += 2) {
638	assertTrue(q.removeFirstOccurrence(new Integer(i)));
639	assertFalse(q.removeFirstOccurrence(new Integer(i + 1)));
640	}
641	assertTrue(q.isEmpty());
642	}
643
644	/**
645	* removeLastOccurrence(x) removes x and returns true if present
646	*/
647	public void testRemoveLastOccurrence() {
648	LinkedList q = populatedQueue(SIZE);
649	for (int i = 1; i < SIZE; i += 2) {
650	assertTrue(q.removeLastOccurrence(new Integer(i)));
651	}
652	for (int i = 0; i < SIZE; i += 2) {
653	assertTrue(q.removeLastOccurrence(new Integer(i)));
654	assertFalse(q.removeLastOccurrence(new Integer(i + 1)));
655	}
656	assertTrue(q.isEmpty());
657	}
658
659	}