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.jupiter.api.Assertions.assertEquals;
  11 import static org.junit.jupiter.api.Assertions.assertFalse;
  12 import static org.junit.jupiter.api.Assertions.assertNull;
  13 import static org.junit.jupiter.api.Assertions.assertSame;
  14 import static org.junit.jupiter.api.Assertions.assertThrows;
  15
  16 import java.util.NoSuchElementException;
  17 import org.junit.jupiter.api.Test;
  18
  19 class EmptyDequeTest {
  20     @Test
  21     void testEmptyDeque() {
  22         final var deque = EmptyDeque.instance();
  23         assertFalse(deque.offer(null));
  24         assertFalse(deque.offerFirst(null));
  25         assertFalse(deque.offerLast(null));
  26         assertNull(deque.peek());
  27         assertNull(deque.peekFirst());
  28         assertNull(deque.peekLast());
  29         assertNull(deque.poll());
  30         assertNull(deque.pollFirst());
  31         assertNull(deque.pollLast());
  32
  33         assertEquals(0, deque.size());
  34         assertFalse(deque.iterator().hasNext());
  35         assertFalse(deque.descendingIterator().hasNext());
  36         assertEquals(0L, deque.spliterator().estimateSize());
  37
  38         final var a = deque.toArray();
  39         assertEquals(0, a.length);
  40         assertSame(a, deque.toArray());
  41         assertSame(a, deque.toArray(a));
  42
  43         assertFalse(deque.removeFirstOccurrence(null));
  44         assertFalse(deque.removeLastOccurrence(null));
  45
  46         assertThrows(IllegalStateException.class, () -> deque.push(null));
  47         assertThrows(IllegalStateException.class, () -> deque.addFirst(null));
  48         assertThrows(IllegalStateException.class, () -> deque.addLast(null));
  49         assertThrows(NoSuchElementException.class, () -> deque.getFirst());
  50         assertThrows(NoSuchElementException.class, () -> deque.getLast());
  51         assertThrows(NoSuchElementException.class, () -> deque.pop());
  52         assertThrows(NoSuchElementException.class, () -> deque.remove());
  53         assertThrows(NoSuchElementException.class, () -> deque.removeFirst());
  54         assertThrows(NoSuchElementException.class, () -> deque.removeLast());
  55     }
  56 }