content: /*
   * Copyright 2015, 2024 StreamEx contributors
   *
   * Licensed 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 one.util.streamex;
  
  import org.junit.Test;
  
  import java.util.AbstractMap;
  import java.util.Spliterator;
  import java.util.Spliterators;
  import java.util.stream.Stream;
  
  import static one.util.streamex.TestHelpers.checkSpliterator;
  import static one.util.streamex.TestHelpers.consumeElement;
  import static org.junit.Assert.*;
  
  /**
   * @author Tagir Valeev
   */
  public class WithFirstSpliteratorTest {
      @Test
      public void testSpliterator() {
          checkSpliterator("withFirst", EntryStream.of(0, 0, 0, 1, 0, 2, 0, 3, 0, 4, 0, 5).toList(),
              () -> new WithFirstSpliterator<>(Stream.of(0, 1, 2, 3, 4, 5).spliterator(),
                      AbstractMap.SimpleImmutableEntry::new));
          checkSpliterator("withFirstFlatMap", EntryStream.of(0, 0, 0, 1, 0, 2, 0, 3, 0, 4, 0, 5).toList(),
              () -> new WithFirstSpliterator<>(Stream.of(0, 2, 4).flatMap(x -> Stream.of(x, x + 1)).parallel()
                      .spliterator(), AbstractMap.SimpleImmutableEntry::new));
      }
      
      @Test
      public void testCharacteristics() {
          WithFirstSpliterator<Integer, Integer> spltr = new WithFirstSpliterator<>(Stream.of(6, 1, 2, 3, 4, 5)
                  .spliterator(), Integer::sum);
          assertTrue(spltr.hasCharacteristics(Spliterator.SIZED));
          assertEquals(6, spltr.getExactSizeIfKnown());
          consumeElement(spltr, 12);
          assertEquals(5, spltr.getExactSizeIfKnown());
          consumeElement(spltr, 7);
          assertEquals(4, spltr.getExactSizeIfKnown());
          
          spltr = new WithFirstSpliterator<>(Spliterators.emptySpliterator(), Integer::sum);
          assertTrue(spltr.hasCharacteristics(Spliterator.SIZED));
          assertEquals(0, spltr.getExactSizeIfKnown());
          assertFalse(spltr.tryAdvance(x -> fail("Should not happen")));
          assertEquals(0, spltr.getExactSizeIfKnown());
          
          WithFirstSpliterator<Long, Long> longSpltr = new WithFirstSpliterator<>(LongStreamEx.range(Long.MAX_VALUE)
                  .spliterator(), Long::sum);
          assertTrue(longSpltr.hasCharacteristics(Spliterator.SIZED));
          assertEquals(Long.MAX_VALUE, longSpltr.getExactSizeIfKnown());
          consumeElement(longSpltr, 0L);
          assertEquals(Long.MAX_VALUE - 1, longSpltr.getExactSizeIfKnown());
          
          longSpltr = new WithFirstSpliterator<>(LongStreamEx.range(-1, Long.MAX_VALUE)
                  .spliterator(), Long::sum);
          assertFalse(longSpltr.hasCharacteristics(Spliterator.SIZED));
          assertEquals(Long.MAX_VALUE, longSpltr.estimateSize());
      }
  }
  