code: /*
   * Copyright (c) 2016-present, RxJava 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 io.reactivex.rxjava3.internal.util;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.*;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.RxJavaTest;
  
  public class MergerBiFunctionTest extends RxJavaTest {
  
      @Test
      public void firstEmpty() throws Exception {
          MergerBiFunction<Integer> merger = new MergerBiFunction<>(new Comparator<Integer>() {
              @Override
              public int compare(Integer o1, Integer o2) {
                  return o1.compareTo(o2);
              }
          });
          List<Integer> list = merger.apply(Collections.<Integer>emptyList(), Arrays.asList(3, 5));
  
          assertEquals(Arrays.asList(3, 5), list);
      }
  
      @Test
      public void bothEmpty() throws Exception {
          MergerBiFunction<Integer> merger = new MergerBiFunction<>(new Comparator<Integer>() {
              @Override
              public int compare(Integer o1, Integer o2) {
                  return o1.compareTo(o2);
              }
          });
          List<Integer> list = merger.apply(Collections.<Integer>emptyList(), Collections.<Integer>emptyList());
  
          assertEquals(Collections.<Integer>emptyList(), list);
      }
  
      @Test
      public void secondEmpty() throws Exception {
          MergerBiFunction<Integer> merger = new MergerBiFunction<>(new Comparator<Integer>() {
              @Override
              public int compare(Integer o1, Integer o2) {
                  return o1.compareTo(o2);
              }
          });
          List<Integer> list = merger.apply(Arrays.asList(2, 4), Collections.<Integer>emptyList());
  
          assertEquals(Arrays.asList(2, 4), list);
      }
  
      @Test
      public void sameSize() throws Exception {
          MergerBiFunction<Integer> merger = new MergerBiFunction<>(new Comparator<Integer>() {
              @Override
              public int compare(Integer o1, Integer o2) {
                  return o1.compareTo(o2);
              }
          });
          List<Integer> list = merger.apply(Arrays.asList(2, 4), Arrays.asList(3, 5));
  
          assertEquals(Arrays.asList(2, 3, 4, 5), list);
      }
  
      @Test
      public void sameSizeReverse() throws Exception {
          MergerBiFunction<Integer> merger = new MergerBiFunction<>(new Comparator<Integer>() {
              @Override
              public int compare(Integer o1, Integer o2) {
                  return o1.compareTo(o2);
              }
          });
          List<Integer> list = merger.apply(Arrays.asList(3, 5), Arrays.asList(2, 4));
  
          assertEquals(Arrays.asList(2, 3, 4, 5), list);
      }
  }
  