content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.kafka.common.utils;
  
  import org.junit.jupiter.api.Test;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.NoSuchElementException;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class AbstractIteratorTest {
  
      @Test
      public void testIterator() {
          int max = 10;
          List<Integer> l = new ArrayList<>();
          for (int i = 0; i < max; i++)
              l.add(i);
          ListIterator<Integer> iter = new ListIterator<>(l);
          for (int i = 0; i < max; i++) {
              Integer value = i;
              assertEquals(value, iter.peek());
              assertTrue(iter.hasNext());
              assertEquals(value, iter.next());
          }
          assertFalse(iter.hasNext());
      }
  
      @Test
      public void testEmptyIterator() {
          Iterator<Object> iter = new ListIterator<>(Collections.emptyList());
          assertThrows(NoSuchElementException.class, iter::next);
      }
  
      static class ListIterator<T> extends AbstractIterator<T> {
          private final List<T> list;
          private int position = 0;
  
          public ListIterator(List<T> l) {
              this.list = l;
          }
  
          protected T makeNext() {
              if (position < list.size())
                  return list.get(position++);
              else
                  return allDone();
          }
      }
  }
  