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.connect.util;
  
  import org.junit.jupiter.api.Test;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  public class ConnectorUtilsTest {
  
      private static final List<Integer> FIVE_ELEMENTS = Arrays.asList(1, 2, 3, 4, 5);
  
      @Test
      public void testGroupPartitions() {
  
          List<List<Integer>> grouped = ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 1);
          assertEquals(Collections.singletonList(FIVE_ELEMENTS), grouped);
  
          grouped = ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 2);
          assertEquals(Arrays.asList(Arrays.asList(1, 2, 3), Arrays.asList(4, 5)), grouped);
  
          grouped = ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 3);
          assertEquals(Arrays.asList(Arrays.asList(1, 2),
                  Arrays.asList(3, 4),
                  Collections.singletonList(5)), grouped);
  
          grouped = ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 5);
          assertEquals(Arrays.asList(Collections.singletonList(1),
                  Collections.singletonList(2),
                  Collections.singletonList(3),
                  Collections.singletonList(4),
                  Collections.singletonList(5)), grouped);
  
          grouped = ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 7);
          assertEquals(Arrays.asList(Collections.singletonList(1),
                  Collections.singletonList(2),
                  Collections.singletonList(3),
                  Collections.singletonList(4),
                  Collections.singletonList(5),
                  Collections.emptyList(),
                  Collections.emptyList()), grouped);
      }
  
      @Test
      public void testGroupPartitionsInvalidCount() {
          assertThrows(IllegalArgumentException.class,
              () -> ConnectorUtils.groupPartitions(FIVE_ELEMENTS, 0));
      }
  }
  