/*
* 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.
*/
package jsr166;
import junit.framework.*;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;
public class LinkedListTest extends JSR166TestCase {
/**
* 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 I = (Integer)(p.remove());
assertFalse(q.contains(I));
}
}
}
/**
* toArray contains all elements in FIFO order
*/
public void testToArray() {
LinkedList q = populatedQueue(SIZE);
Object[] o = q.toArray();
for (int i = 0; i < o.length; i++)
assertSame(o[i], q.poll());
}
/**
* toArray(a) contains all elements in FIFO order
*/
public void testToArray2() {
LinkedList<Integer> q = populatedQueue(SIZE);
Integer[] ints = new Integer[SIZE];
Integer[] array = q.toArray(ints);
assertSame(ints, array);
for (int i = 0; i < ints.length; i++)
assertSame(ints[i], q.poll());
}
/**
* toArray(null) throws NullPointerException
*/
public void testToArray_NullArg() {
LinkedList l = new LinkedList();
l.add(new Object());
try {
l.toArray(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* toArray(incompatible array type) throws ArrayStoreException
*/
public void testToArray1_BadArg() {
LinkedList l = new LinkedList();
l.add(new Integer(5));
try {
l.toArray(new String[10]);
shouldThrow();
} catch (ArrayStoreException success) {}
}
/**
* iterator iterates through all elements
*/
public void testIterator() {
LinkedList q = populatedQueue(SIZE);
int i = 0;
Iterator it = q.iterator();
while (it.hasNext()) {
assertTrue(q.contains(it.next()));
++i;
}
assertEquals(i, SIZE);
}
/**
* iterator ordering is FIFO
*/
public void testIteratorOrdering() {
final LinkedList q = new LinkedList();
q.add(new Integer(1));
q.add(new Integer(2));
q.add(new Integer(3));
int k = 0;
for (Iterator it = q.iterator(); it.hasNext();) {
assertEquals(++k, it.next());
}
assertEquals(3, k);
}
/**
* iterator.remove removes current element
*/
public void testIteratorRemove() {
final LinkedList q = new LinkedList();
q.add(new Integer(1));
q.add(new Integer(2));
q.add(new Integer(3));
Iterator it = q.iterator();
assertEquals(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());
}
}