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.operators.single;
  
  import static org.junit.Assert.assertTrue;
  
  import java.util.*;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class SingleMergeTest extends RxJavaTest {
  
      @Test
      public void mergeSingleSingle() {
  
          Single.merge(Single.just(Single.just(1)))
          .test()
          .assertResult(1);
      }
  
      @Test
      public void merge2() {
          Single.merge(Single.just(1), Single.just(2))
          .test()
          .assertResult(1, 2);
      }
  
      @Test
      public void merge3() {
          Single.merge(Single.just(1), Single.just(2), Single.just(3))
          .test()
          .assertResult(1, 2, 3);
      }
  
      @Test
      public void merge4() {
          Single.merge(Single.just(1), Single.just(2), Single.just(3), Single.just(4))
          .test()
          .assertResult(1, 2, 3, 4);
      }
  
      @Test
      public void mergeErrors() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              Single<Integer> source1 = Single.error(new TestException("First"));
              Single<Integer> source2 = Single.error(new TestException("Second"));
  
              Single.merge(source1, source2)
              .to(TestHelper.<Integer>testConsumer())
              .assertFailureAndMessage(TestException.class, "First");
  
              assertTrue(errors.toString(), errors.isEmpty());
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void mergeDelayErrorIterable() {
          Single.mergeDelayError(Arrays.asList(
                  Single.just(1),
                  Single.<Integer>error(new TestException()),
                  Single.just(2))
          )
          .test()
          .assertFailure(TestException.class, 1, 2);
      }
  
      @Test
      public void mergeDelayErrorPublisher() {
          Single.mergeDelayError(Flowable.just(
                  Single.just(1),
                  Single.<Integer>error(new TestException()),
                  Single.just(2))
          )
          .test()
          .assertFailure(TestException.class, 1, 2);
      }
  
      @Test
      public void mergeDelayError2() {
          Single.mergeDelayError(
                  Single.just(1),
                  Single.<Integer>error(new TestException())
          )
          .test()
          .assertFailure(TestException.class, 1);
      }
  
      @Test
      public void mergeDelayError2ErrorFirst() {
          Single.mergeDelayError(
                  Single.<Integer>error(new TestException()),
                  Single.just(1)
          )
          .test()
          .assertFailure(TestException.class, 1);
      }
  
      @Test
      public void mergeDelayError3() {
          Single.mergeDelayError(
                  Single.just(1),
                  Single.<Integer>error(new TestException()),
                  Single.just(2)
          )
          .test()
          .assertFailure(TestException.class, 1, 2);
      }
  
      @Test
      public void mergeDelayError4() {
          Single.mergeDelayError(
                  Single.just(1),
                  Single.<Integer>error(new TestException()),
                  Single.just(2),
                  Single.just(3)
          )
          .test()
          .assertFailure(TestException.class, 1, 2, 3);
      }
  }
  