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 static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.io.IOException;
  
  import org.junit.Test;
  import org.mockito.InOrder;
  
  import io.reactivex.rxjava3.annotations.NonNull;
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class SingleSafeSubscribeTest {
  
      @Test
      public void normalSuccess() throws Throwable {
          TestHelper.withErrorTracking(errors -> {
              @SuppressWarnings("unchecked")
              SingleObserver<Integer> consumer = mock(SingleObserver.class);
  
              Single.just(1)
              .safeSubscribe(consumer);
  
              InOrder order = inOrder(consumer);
              order.verify(consumer).onSubscribe(any(Disposable.class));
              order.verify(consumer).onSuccess(1);
              order.verifyNoMoreInteractions();
  
              assertTrue("" + errors, errors.isEmpty());
          });
      }
  
      @Test
      public void normalError() throws Throwable  {
          TestHelper.withErrorTracking(errors -> {
              @SuppressWarnings("unchecked")
              SingleObserver<Integer> consumer = mock(SingleObserver.class);
  
              Single.<Integer>error(new TestException())
              .safeSubscribe(consumer);
  
              InOrder order = inOrder(consumer);
              order.verify(consumer).onSubscribe(any(Disposable.class));
              order.verify(consumer).onError(any(TestException.class));
              order.verifyNoMoreInteractions();
  
              assertTrue("" + errors, errors.isEmpty());
          });
      }
  
      @Test
      public void onSubscribeCrash() throws Throwable {
          TestHelper.withErrorTracking(errors -> {
              @SuppressWarnings("unchecked")
              SingleObserver<Integer> consumer = mock(SingleObserver.class);
              doThrow(new TestException()).when(consumer).onSubscribe(any());
  
              Disposable d = Disposable.empty();
  
              new Single<Integer>() {
                  @Override
                  protected void subscribeActual(@NonNull SingleObserver<? super Integer> observer) {
                      observer.onSubscribe(d);
                      // none of the following should arrive at the consumer
                      observer.onSuccess(1);
                      observer.onError(new IOException());
                  }
              }
              .safeSubscribe(consumer);
  
              InOrder order = inOrder(consumer);
              order.verify(consumer).onSubscribe(any(Disposable.class));
              order.verifyNoMoreInteractions();
  
              assertTrue(d.isDisposed());
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class);
              TestHelper.assertUndeliverable(errors, 1, IOException.class);
          });
      }
  
      @Test
      public void onSuccessCrash() throws Throwable {
          TestHelper.withErrorTracking(errors -> {
              @SuppressWarnings("unchecked")
              SingleObserver<Integer> consumer = mock(SingleObserver.class);
              doThrow(new TestException()).when(consumer).onSuccess(any());
  
              new Single<Integer>() {
                  @Override
                  protected void subscribeActual(@NonNull SingleObserver<? super Integer> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onSuccess(1);
                  }
              }
              .safeSubscribe(consumer);
  
              InOrder order = inOrder(consumer);
              order.verify(consumer).onSubscribe(any(Disposable.class));
              order.verify(consumer).onSuccess(1);
              order.verifyNoMoreInteractions();
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class);
          });
      }
  
      @Test
      public void onErrorCrash() throws Throwable  {
          TestHelper.withErrorTracking(errors -> {
              @SuppressWarnings("unchecked")
              SingleObserver<Integer> consumer = mock(SingleObserver.class);
              doThrow(new TestException()).when(consumer).onError(any());
  
              new Single<Integer>() {
                  @Override
                  protected void subscribeActual(@NonNull SingleObserver<? super Integer> observer) {
                      observer.onSubscribe(Disposable.empty());
                      // none of the following should arrive at the consumer
                      observer.onError(new IOException());
                  }
              }
              .safeSubscribe(consumer);
  
              InOrder order = inOrder(consumer);
              order.verify(consumer).onSubscribe(any(Disposable.class));
              order.verify(consumer).onError(any(IOException.class));
              order.verifyNoMoreInteractions();
  
              TestHelper.assertError(errors, 0, CompositeException.class);
  
              CompositeException compositeException = (CompositeException)errors.get(0);
              TestHelper.assertError(compositeException.getExceptions(), 0, IOException.class);
              TestHelper.assertError(compositeException.getExceptions(), 1, TestException.class);
          });
      }
  }
  