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; }
        }
        return newTestSuite(LinkedListTest.class,
                            CollectionTest.testSuite(new Implementation()));
    }

    /**
     * Returns a new queue of given size containing consecutive
     * Integers 0 ... n - 1.
     */
    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());
        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:	1.42
Committed:	Mon Oct 17 00:56:11 2016 UTC (7 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.41:	+9 -1 lines
Log Message:	add CollectionImplementation tests
#	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	return newTestSuite(LinkedListTest.class,
32	CollectionTest.testSuite(new Implementation()));
33	}
34
35	/**
36	* Returns a new queue of given size containing consecutive
37	* Integers 0 ... n - 1.
38	*/
39	private LinkedList<Integer> populatedQueue(int n) {
40	LinkedList<Integer> q = new LinkedList<Integer>();
41	assertTrue(q.isEmpty());
42	for (int i = 0; i < n; ++i)
43	assertTrue(q.offer(new Integer(i)));
44	assertFalse(q.isEmpty());
45	assertEquals(n, q.size());
46	assertEquals((Integer) 0, q.peekFirst());
47	assertEquals((Integer) (n - 1), q.peekLast());
48	return q;
49	}
50
51	/**
52	* new queue is empty
53	*/
54	public void testConstructor1() {
55	assertEquals(0, new LinkedList().size());
56	}
57
58	/**
59	* Initializing from null Collection throws NPE
60	*/
61	public void testConstructor3() {
62	try {
63	new LinkedList((Collection)null);
64	shouldThrow();
65	} catch (NullPointerException success) {}
66	}
67
68	/**
69	* Queue contains all elements of collection used to initialize
70	*/
71	public void testConstructor6() {
72	Integer[] ints = new Integer[SIZE];
73	for (int i = 0; i < SIZE; ++i)
74	ints[i] = i;
75	LinkedList q = new LinkedList(Arrays.asList(ints));
76	for (int i = 0; i < SIZE; ++i)
77	assertEquals(ints[i], q.poll());
78	}
79
80	/**
81	* isEmpty is true before add, false after
82	*/
83	public void testEmpty() {
84	LinkedList q = new LinkedList();
85	assertTrue(q.isEmpty());
86	q.add(new Integer(1));
87	assertFalse(q.isEmpty());
88	q.add(new Integer(2));
89	q.remove();
90	q.remove();
91	assertTrue(q.isEmpty());
92	}
93
94	/**
95	* size changes when elements added and removed
96	*/
97	public void testSize() {
98	LinkedList q = populatedQueue(SIZE);
99	for (int i = 0; i < SIZE; ++i) {
100	assertEquals(SIZE - i, q.size());
101	q.remove();
102	}
103	for (int i = 0; i < SIZE; ++i) {
104	assertEquals(i, q.size());
105	q.add(new Integer(i));
106	}
107	}
108
109	/**
110	* offer(null) succeeds
111	*/
112	public void testOfferNull() {
113	LinkedList q = new LinkedList();
114	q.offer(null);
115	assertNull(q.get(0));
116	assertTrue(q.contains(null));
117	}
118
119	/**
120	* Offer succeeds
121	*/
122	public void testOffer() {
123	LinkedList q = new LinkedList();
124	assertTrue(q.offer(new Integer(0)));
125	assertTrue(q.offer(new Integer(1)));
126	}
127
128	/**
129	* add succeeds
130	*/
131	public void testAdd() {
132	LinkedList q = new LinkedList();
133	for (int i = 0; i < SIZE; ++i) {
134	assertEquals(i, q.size());
135	assertTrue(q.add(new Integer(i)));
136	}
137	}
138
139	/**
140	* addAll(null) throws NPE
141	*/
142	public void testAddAll1() {
143	LinkedList q = new LinkedList();
144	try {
145	q.addAll(null);
146	shouldThrow();
147	} catch (NullPointerException success) {}
148	}
149
150	/**
151	* Queue contains all elements, in traversal order, of successful addAll
152	*/
153	public void testAddAll5() {
154	Integer[] empty = new Integer[0];
155	Integer[] ints = new Integer[SIZE];
156	for (int i = 0; i < SIZE; ++i)
157	ints[i] = i;
158	LinkedList q = new LinkedList();
159	assertFalse(q.addAll(Arrays.asList(empty)));
160	assertTrue(q.addAll(Arrays.asList(ints)));
161	for (int i = 0; i < SIZE; ++i)
162	assertEquals(ints[i], q.poll());
163	}
164
165	/**
166	* addAll with too large an index throws IOOBE
167	*/
168	public void testAddAll2_IndexOutOfBoundsException() {
169	LinkedList l = new LinkedList();
170	l.add(new Object());
171	LinkedList m = new LinkedList();
172	m.add(new Object());
173	try {
174	l.addAll(4,m);
175	shouldThrow();
176	} catch (IndexOutOfBoundsException success) {}
177	}
178
179	/**
180	* addAll with negative index throws IOOBE
181	*/
182	public void testAddAll4_BadIndex() {
183	LinkedList l = new LinkedList();
184	l.add(new Object());
185	LinkedList m = new LinkedList();
186	m.add(new Object());
187	try {
188	l.addAll(-1,m);
189	shouldThrow();
190	} catch (IndexOutOfBoundsException success) {}
191	}
192
193	/**
194	* poll succeeds unless empty
195	*/
196	public void testPoll() {
197	LinkedList q = populatedQueue(SIZE);
198	for (int i = 0; i < SIZE; ++i) {
199	assertEquals(i, q.poll());
200	}
201	assertNull(q.poll());
202	}
203
204	/**
205	* peek returns next element, or null if empty
206	*/
207	public void testPeek() {
208	LinkedList q = populatedQueue(SIZE);
209	for (int i = 0; i < SIZE; ++i) {
210	assertEquals(i, q.peek());
211	assertEquals(i, q.poll());
212	assertTrue(q.peek() == null \|\|
213	!q.peek().equals(i));
214	}
215	assertNull(q.peek());
216	}
217
218	/**
219	* element returns next element, or throws NSEE if empty
220	*/
221	public void testElement() {
222	LinkedList q = populatedQueue(SIZE);
223	for (int i = 0; i < SIZE; ++i) {
224	assertEquals(i, q.element());
225	assertEquals(i, q.poll());
226	}
227	try {
228	q.element();
229	shouldThrow();
230	} catch (NoSuchElementException success) {}
231	}
232
233	/**
234	* remove removes next element, or throws NSEE if empty
235	*/
236	public void testRemove() {
237	LinkedList q = populatedQueue(SIZE);
238	for (int i = 0; i < SIZE; ++i) {
239	assertEquals(i, q.remove());
240	}
241	try {
242	q.remove();
243	shouldThrow();
244	} catch (NoSuchElementException success) {}
245	}
246
247	/**
248	* remove(x) removes x and returns true if present
249	*/
250	public void testRemoveElement() {
251	LinkedList q = populatedQueue(SIZE);
252	for (int i = 1; i < SIZE; i += 2) {
253	assertTrue(q.contains(i));
254	assertTrue(q.remove((Integer)i));
255	assertFalse(q.contains(i));
256	assertTrue(q.contains(i - 1));
257	}
258	for (int i = 0; i < SIZE; i += 2) {
259	assertTrue(q.contains(i));
260	assertTrue(q.remove((Integer)i));
261	assertFalse(q.contains(i));
262	assertFalse(q.remove((Integer)(i + 1)));
263	assertFalse(q.contains(i + 1));
264	}
265	assertTrue(q.isEmpty());
266	}
267
268	/**
269	* contains(x) reports true when elements added but not yet removed
270	*/
271	public void testContains() {
272	LinkedList q = populatedQueue(SIZE);
273	for (int i = 0; i < SIZE; ++i) {
274	assertTrue(q.contains(new Integer(i)));
275	q.poll();
276	assertFalse(q.contains(new Integer(i)));
277	}
278	}
279
280	/**
281	* clear removes all elements
282	*/
283	public void testClear() {
284	LinkedList q = populatedQueue(SIZE);
285	q.clear();
286	assertTrue(q.isEmpty());
287	assertEquals(0, q.size());
288	assertTrue(q.add(new Integer(1)));
289	assertFalse(q.isEmpty());
290	q.clear();
291	assertTrue(q.isEmpty());
292	}
293
294	/**
295	* containsAll(c) is true when c contains a subset of elements
296	*/
297	public void testContainsAll() {
298	LinkedList q = populatedQueue(SIZE);
299	LinkedList p = new LinkedList();
300	for (int i = 0; i < SIZE; ++i) {
301	assertTrue(q.containsAll(p));
302	assertFalse(p.containsAll(q));
303	assertTrue(p.add(new Integer(i)));
304	}
305	assertTrue(p.containsAll(q));
306	}
307
308	/**
309	* retainAll(c) retains only those elements of c and reports true if changed
310	*/
311	public void testRetainAll() {
312	LinkedList q = populatedQueue(SIZE);
313	LinkedList p = populatedQueue(SIZE);
314	for (int i = 0; i < SIZE; ++i) {
315	boolean changed = q.retainAll(p);
316	if (i == 0)
317	assertFalse(changed);
318	else
319	assertTrue(changed);
320
321	assertTrue(q.containsAll(p));
322	assertEquals(SIZE - i, q.size());
323	p.remove();
324	}
325	}
326
327	/**
328	* removeAll(c) removes only those elements of c and reports true if changed
329	*/
330	public void testRemoveAll() {
331	for (int i = 1; i < SIZE; ++i) {
332	LinkedList q = populatedQueue(SIZE);
333	LinkedList p = populatedQueue(i);
334	assertTrue(q.removeAll(p));
335	assertEquals(SIZE - i, q.size());
336	for (int j = 0; j < i; ++j) {
337	Integer x = (Integer)(p.remove());
338	assertFalse(q.contains(x));
339	}
340	}
341	}
342
343	/**
344	* toArray contains all elements in FIFO order
345	*/
346	public void testToArray() {
347	LinkedList q = populatedQueue(SIZE);
348	Object[] o = q.toArray();
349	for (int i = 0; i < o.length; i++)
350	assertSame(o[i], q.poll());
351	}
352
353	/**
354	* toArray(a) contains all elements in FIFO order
355	*/
356	public void testToArray2() {
357	LinkedList<Integer> q = populatedQueue(SIZE);
358	Integer[] ints = new Integer[SIZE];
359	Integer[] array = q.toArray(ints);
360	assertSame(ints, array);
361	for (int i = 0; i < ints.length; i++)
362	assertSame(ints[i], q.poll());
363	}
364
365	/**
366	* toArray(null) throws NullPointerException
367	*/
368	public void testToArray_NullArg() {
369	LinkedList l = new LinkedList();
370	l.add(new Object());
371	try {
372	l.toArray(null);
373	shouldThrow();
374	} catch (NullPointerException success) {}
375	}
376
377	/**
378	* toArray(incompatible array type) throws ArrayStoreException
379	*/
380	public void testToArray1_BadArg() {
381	LinkedList l = new LinkedList();
382	l.add(new Integer(5));
383	try {
384	l.toArray(new String[10]);
385	shouldThrow();
386	} catch (ArrayStoreException success) {}
387	}
388
389	/**
390	* iterator iterates through all elements
391	*/
392	public void testIterator() {
393	LinkedList q = populatedQueue(SIZE);
394	Iterator it = q.iterator();
395	int i;
396	for (i = 0; it.hasNext(); i++)
397	assertTrue(q.contains(it.next()));
398	assertEquals(i, SIZE);
399	assertIteratorExhausted(it);
400	}
401
402	/**
403	* iterator of empty collection has no elements
404	*/
405	public void testEmptyIterator() {
406	assertIteratorExhausted(new LinkedList().iterator());
407	}
408
409	/**
410	* iterator ordering is FIFO
411	*/
412	public void testIteratorOrdering() {
413	final LinkedList q = new LinkedList();
414	q.add(new Integer(1));
415	q.add(new Integer(2));
416	q.add(new Integer(3));
417	int k = 0;
418	for (Iterator it = q.iterator(); it.hasNext();) {
419	assertEquals(++k, it.next());
420	}
421
422	assertEquals(3, k);
423	}
424
425	/**
426	* iterator.remove removes current element
427	*/
428	public void testIteratorRemove() {
429	final LinkedList q = new LinkedList();
430	q.add(new Integer(1));
431	q.add(new Integer(2));
432	q.add(new Integer(3));
433	Iterator it = q.iterator();
434	assertEquals(1, it.next());
435	it.remove();
436	it = q.iterator();
437	assertEquals(2, it.next());
438	assertEquals(3, it.next());
439	assertFalse(it.hasNext());
440	}
441
442	/**
443	* Descending iterator iterates through all elements
444	*/
445	public void testDescendingIterator() {
446	LinkedList q = populatedQueue(SIZE);
447	int i = 0;
448	Iterator it = q.descendingIterator();
449	while (it.hasNext()) {
450	assertTrue(q.contains(it.next()));
451	++i;
452	}
453	assertEquals(i, SIZE);
454	assertFalse(it.hasNext());
455	try {
456	it.next();
457	shouldThrow();
458	} catch (NoSuchElementException success) {}
459	}
460
461	/**
462	* Descending iterator ordering is reverse FIFO
463	*/
464	public void testDescendingIteratorOrdering() {
465	final LinkedList q = new LinkedList();
466	q.add(new Integer(3));
467	q.add(new Integer(2));
468	q.add(new Integer(1));
469	int k = 0;
470	for (Iterator it = q.descendingIterator(); it.hasNext();) {
471	assertEquals(++k, it.next());
472	}
473
474	assertEquals(3, k);
475	}
476
477	/**
478	* descendingIterator.remove removes current element
479	*/
480	public void testDescendingIteratorRemove() {
481	final LinkedList q = new LinkedList();
482	q.add(three);
483	q.add(two);
484	q.add(one);
485	Iterator it = q.descendingIterator();
486	it.next();
487	it.remove();
488	it = q.descendingIterator();
489	assertSame(it.next(), two);
490	assertSame(it.next(), three);
491	assertFalse(it.hasNext());
492	}
493
494	/**
495	* toString contains toStrings of elements
496	*/
497	public void testToString() {
498	LinkedList q = populatedQueue(SIZE);
499	String s = q.toString();
500	for (int i = 0; i < SIZE; ++i) {
501	assertTrue(s.contains(String.valueOf(i)));
502	}
503	}
504
505	/**
506	* peek returns element inserted with addFirst
507	*/
508	public void testAddFirst() {
509	LinkedList q = populatedQueue(3);
510	q.addFirst(four);
511	assertSame(four, q.peek());
512	}
513
514	/**
515	* peekFirst returns element inserted with push
516	*/
517	public void testPush() {
518	LinkedList q = populatedQueue(3);
519	q.push(four);
520	assertSame(four, q.peekFirst());
521	}
522
523	/**
524	* pop removes next element, or throws NSEE if empty
525	*/
526	public void testPop() {
527	LinkedList q = populatedQueue(SIZE);
528	for (int i = 0; i < SIZE; ++i) {
529	assertEquals(i, q.pop());
530	}
531	try {
532	q.pop();
533	shouldThrow();
534	} catch (NoSuchElementException success) {}
535	}
536
537	/**
538	* OfferFirst succeeds
539	*/
540	public void testOfferFirst() {
541	LinkedList q = new LinkedList();
542	assertTrue(q.offerFirst(new Integer(0)));
543	assertTrue(q.offerFirst(new Integer(1)));
544	}
545
546	/**
547	* OfferLast succeeds
548	*/
549	public void testOfferLast() {
550	LinkedList q = new LinkedList();
551	assertTrue(q.offerLast(new Integer(0)));
552	assertTrue(q.offerLast(new Integer(1)));
553	}
554
555	/**
556	* pollLast succeeds unless empty
557	*/
558	public void testPollLast() {
559	LinkedList q = populatedQueue(SIZE);
560	for (int i = SIZE - 1; i >= 0; --i) {
561	assertEquals(i, q.pollLast());
562	}
563	assertNull(q.pollLast());
564	}
565
566	/**
567	* peekFirst returns next element, or null if empty
568	*/
569	public void testPeekFirst() {
570	LinkedList q = populatedQueue(SIZE);
571	for (int i = 0; i < SIZE; ++i) {
572	assertEquals(i, q.peekFirst());
573	assertEquals(i, q.pollFirst());
574	assertTrue(q.peekFirst() == null \|\|
575	!q.peekFirst().equals(i));
576	}
577	assertNull(q.peekFirst());
578	}
579
580	/**
581	* peekLast returns next element, or null if empty
582	*/
583	public void testPeekLast() {
584	LinkedList q = populatedQueue(SIZE);
585	for (int i = SIZE - 1; i >= 0; --i) {
586	assertEquals(i, q.peekLast());
587	assertEquals(i, q.pollLast());
588	assertTrue(q.peekLast() == null \|\|
589	!q.peekLast().equals(i));
590	}
591	assertNull(q.peekLast());
592	}
593
594	public void testFirstElement() {
595	LinkedList q = populatedQueue(SIZE);
596	for (int i = 0; i < SIZE; ++i) {
597	assertEquals(i, q.getFirst());
598	assertEquals(i, q.pollFirst());
599	}
600	try {
601	q.getFirst();
602	shouldThrow();
603	} catch (NoSuchElementException success) {}
604	}
605
606	/**
607	* getLast returns next element, or throws NSEE if empty
608	*/
609	public void testLastElement() {
610	LinkedList q = populatedQueue(SIZE);
611	for (int i = SIZE - 1; i >= 0; --i) {
612	assertEquals(i, q.getLast());
613	assertEquals(i, q.pollLast());
614	}
615	try {
616	q.getLast();
617	shouldThrow();
618	} catch (NoSuchElementException success) {}
619	assertNull(q.peekLast());
620	}
621
622	/**
623	* removeFirstOccurrence(x) removes x and returns true if present
624	*/
625	public void testRemoveFirstOccurrence() {
626	LinkedList q = populatedQueue(SIZE);
627	for (int i = 1; i < SIZE; i += 2) {
628	assertTrue(q.removeFirstOccurrence(new Integer(i)));
629	}
630	for (int i = 0; i < SIZE; i += 2) {
631	assertTrue(q.removeFirstOccurrence(new Integer(i)));
632	assertFalse(q.removeFirstOccurrence(new Integer(i + 1)));
633	}
634	assertTrue(q.isEmpty());
635	}
636
637	/**
638	* removeLastOccurrence(x) removes x and returns true if present
639	*/
640	public void testRemoveLastOccurrence() {
641	LinkedList q = populatedQueue(SIZE);
642	for (int i = 1; i < SIZE; i += 2) {
643	assertTrue(q.removeLastOccurrence(new Integer(i)));
644	}
645	for (int i = 0; i < SIZE; i += 2) {
646	assertTrue(q.removeLastOccurrence(new Integer(i)));
647	assertFalse(q.removeLastOccurrence(new Integer(i + 1)));
648	}
649	assertTrue(q.isEmpty());
650	}
651
652	}