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.coordinator.group.assignor;
  
  import org.junit.jupiter.api.Test;
  
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.Set;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  
  public class RangeSetTest {
      @Test
      void testNegativeSize() {
          assertThrows(IllegalArgumentException.class, () -> new RangeSet(0, -1));
      }
  
      @Test
      void testOverflow() {
          // This range is the maximum size we allow.
          assertDoesNotThrow(() -> new RangeSet(0, Integer.MAX_VALUE));
  
          assertThrows(IllegalArgumentException.class, () -> new RangeSet(-1, Integer.MAX_VALUE));
      }
  
      @Test
      void testSize() {
          RangeSet rangeSet = new RangeSet(5, 10);
          assertEquals(5, rangeSet.size());
      }
  
      @Test
      void testIsEmpty() {
          RangeSet rangeSet = new RangeSet(5, 5);
          assertTrue(rangeSet.isEmpty());
      }
  
      @Test
      void testContains() {
          RangeSet rangeSet = new RangeSet(5, 10);
          assertTrue(rangeSet.contains(5));
          assertTrue(rangeSet.contains(9));
          assertFalse(rangeSet.contains(10));
          assertFalse(rangeSet.contains(4));
      }
  
      @Test
      void testIterator() {
          RangeSet rangeSet = new RangeSet(5, 10);
          Iterator<Integer> iterator = rangeSet.iterator();
          for (int i = 5; i < 10; i++) {
              assertTrue(iterator.hasNext());
              assertEquals(i, iterator.next());
          }
          assertFalse(iterator.hasNext());
          assertThrows(NoSuchElementException.class, iterator::next);
      }
  
      @Test
      void testUnsupportedOperations() {
          RangeSet rangeSet = new RangeSet(5, 10);
          assertThrows(UnsupportedOperationException.class, () -> rangeSet.add(5));
          assertThrows(UnsupportedOperationException.class, () -> rangeSet.remove(5));
          assertThrows(UnsupportedOperationException.class, () -> rangeSet.addAll(null));
          assertThrows(UnsupportedOperationException.class, () -> rangeSet.retainAll(null));
          assertThrows(UnsupportedOperationException.class, () -> rangeSet.removeAll(null));
          assertThrows(UnsupportedOperationException.class, rangeSet::clear);
      }
  
      @Test
      void testToArray() {
          RangeSet rangeSet = new RangeSet(5, 10);
          Object[] expectedArray = {5, 6, 7, 8, 9};
          assertArrayEquals(expectedArray, rangeSet.toArray());
      }
  
      @Test
      void testToArrayWithArrayParameter() {
          RangeSet rangeSet = new RangeSet(5, 10);
          Integer[] inputArray = new Integer[5];
          Integer[] expectedArray = {5, 6, 7, 8, 9};
          assertArrayEquals(expectedArray, rangeSet.toArray(inputArray));
      }
  
      @Test
      void testContainsAll() {
          RangeSet rangeSet = new RangeSet(5, 10);
          assertTrue(rangeSet.containsAll(Set.of(5, 6, 7, 8, 9)));
          assertFalse(rangeSet.containsAll(Set.of(5, 6, 10)));
      }
  
      @Test
      void testToString() {
          RangeSet rangeSet = new RangeSet(5, 8);
          assertEquals("RangeSet(from=5 (inclusive), to=8 (exclusive))", rangeSet.toString());
      }
  
      @Test
      void testEquals() {
          RangeSet rangeSet1 = new RangeSet(5, 10);
          RangeSet rangeSet2 = new RangeSet(5, 10);
          RangeSet rangeSet3 = new RangeSet(6, 10);
          Set<Integer> set = Set.of(5, 6, 7, 8, 9);
          HashSet<Integer> hashSet = new HashSet<>(Set.of(6, 7, 8, 9));
  
          assertEquals(rangeSet1, rangeSet2);
          assertNotEquals(rangeSet1, rangeSet3);
          assertEquals(rangeSet1, set);
          assertEquals(rangeSet3, hashSet);
          assertNotEquals(rangeSet1, new Object());
  
          // Empty sets are equal.
          RangeSet emptyRangeSet1 = new RangeSet(0, 0);
          RangeSet emptyRangeSet2 = new RangeSet(5, 5);
          Set<Integer> emptySet = Set.of();
  
          assertEquals(emptySet, emptyRangeSet1);
          assertEquals(emptySet, emptyRangeSet2);
          assertEquals(emptyRangeSet1, emptyRangeSet2);
      }
  
      @Test
      void testHashCode() {
          RangeSet rangeSet1 = new RangeSet(5, 10);
          RangeSet rangeSet2 = new RangeSet(6, 10);
  
          assertEquals(Set.of(5, 6, 7, 8, 9).hashCode(), rangeSet1.hashCode());
          assertEquals(Set.of(6, 7, 8, 9).hashCode(), rangeSet2.hashCode());
  
          RangeSet emptySet = new RangeSet(5, 5);
          assertEquals(Set.of().hashCode(), emptySet.hashCode());
  
          // Both these cases overflow the range of an int when calculating the hash code. They're
          // chosen so that their hash codes are almost the same except for the most significant bit.
          RangeSet overflowRangeSet1 = new RangeSet(0x3FFFFFFD, 0x3FFFFFFF);
          RangeSet overflowRangeSet2 = new RangeSet(0x7FFFFFFD, 0x7FFFFFFF);
          assertEquals(
              Set.of(0x3FFFFFFD, 0x3FFFFFFE).hashCode(),
              overflowRangeSet1.hashCode() // == 0x0_FFFFFFF6 / 2
          );
          assertEquals(
              Set.of(0x7FFFFFFD, 0x7FFFFFFE).hashCode(),
              overflowRangeSet2.hashCode() // == 0x1_FFFFFFF6 / 2
          );
      }
  }
  