common/util/src/test/java/org/opendaylight/yangtools/util/EmptyDequeTest.java

   1 /*
   2  * Copyright (c) 2018 Pantheon Technologies, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.yangtools.util;
   9
  10 import static org.junit.Assert.assertEquals;
  11 import static org.junit.Assert.assertFalse;
  12 import static org.junit.Assert.assertNull;
  13 import static org.junit.Assert.assertSame;
  14 import static org.junit.Assert.fail;
  15
  16 import java.util.NoSuchElementException;
  17 import org.junit.Test;
  18
  19 public class EmptyDequeTest {
  20
  21     @Test
  22     public void testEmptyDeque() {
  23         final EmptyDeque<?> deque = EmptyDeque.instance();
  24         assertFalse(deque.offer(null));
  25         assertFalse(deque.offerFirst(null));
  26         assertFalse(deque.offerLast(null));
  27         assertNull(deque.peek());
  28         assertNull(deque.peekFirst());
  29         assertNull(deque.peekLast());
  30         assertNull(deque.poll());
  31         assertNull(deque.pollFirst());
  32         assertNull(deque.pollLast());
  33
  34         assertEquals(0, deque.size());
  35         assertFalse(deque.iterator().hasNext());
  36         assertFalse(deque.descendingIterator().hasNext());
  37         assertEquals(0L, deque.spliterator().estimateSize());
  38
  39         final Object[] a = deque.toArray();
  40         assertEquals(0, a.length);
  41         assertSame(a, deque.toArray());
  42         assertSame(a, deque.toArray(a));
  43
  44         assertFalse(deque.removeFirstOccurrence(null));
  45         assertFalse(deque.removeLastOccurrence(null));
  46
  47         try {
  48             deque.push(null);
  49             fail();
  50         } catch (IllegalStateException e) {
  51             // expeced
  52         }
  53         try {
  54             deque.addFirst(null);
  55             fail();
  56         } catch (IllegalStateException e) {
  57             // expeced
  58         }
  59         try {
  60             deque.addLast(null);
  61             fail();
  62         } catch (IllegalStateException e) {
  63             // expeced
  64         }
  65
  66         try {
  67             deque.getFirst();
  68             fail();
  69         } catch (NoSuchElementException e) {
  70             // expeced
  71         }
  72         try {
  73             deque.getLast();
  74             fail();
  75         } catch (NoSuchElementException e) {
  76             // expeced
  77         }
  78         try {
  79             deque.pop();
  80             fail();
  81         } catch (NoSuchElementException e) {
  82             // expeced
  83         }
  84         try {
  85             deque.remove();
  86             fail();
  87         } catch (NoSuchElementException e) {
  88             // expeced
  89         }
  90         try {
  91             deque.removeFirst();
  92             fail();
  93         } catch (NoSuchElementException e) {
  94             // expeced
  95         }
  96         try {
  97             deque.removeLast();
  98             fail();
  99         } catch (NoSuchElementException e) {
 100             // expeced
 101         }
 102     }
 103 }