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.observable;
  
  import static org.junit.Assert.assertNull;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.util.*;
  
  import org.junit.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.core.Observable;
  import io.reactivex.rxjava3.core.Observer;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.operators.QueueFuseable;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import io.reactivex.rxjava3.subjects.UnicastSubject;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class ObservableMapTest extends RxJavaTest {
  
      Observer<String> stringObserver;
      Observer<String> stringObserver2;
  
      static final BiFunction<String, Integer, String> APPEND_INDEX = new BiFunction<String, Integer, String>() {
          @Override
          public String apply(String value, Integer index) {
              return value + index;
          }
      };
  
      @Before
      public void before() {
          stringObserver = TestHelper.mockObserver();
          stringObserver2 = TestHelper.mockObserver();
      }
  
      @Test
      public void map() {
          Map<String, String> m1 = getMap("One");
          Map<String, String> m2 = getMap("Two");
          Observable<Map<String, String>> o = Observable.just(m1, m2);
  
          Observable<String> m = o.map(new Function<Map<String, String>, String>() {
              @Override
              public String apply(Map<String, String> map) {
                  return map.get("firstName");
              }
          });
  
          m.subscribe(stringObserver);
  
          verify(stringObserver, never()).onError(any(Throwable.class));
          verify(stringObserver, times(1)).onNext("OneFirst");
          verify(stringObserver, times(1)).onNext("TwoFirst");
          verify(stringObserver, times(1)).onComplete();
      }
  
      @Test
      public void mapMany() {
          /* simulate a top-level async call which returns IDs */
          Observable<Integer> ids = Observable.just(1, 2);
  
          /* now simulate the behavior to take those IDs and perform nested async calls based on them */
          Observable<String> m = ids.flatMap(new Function<Integer, Observable<String>>() {
  
              @Override
              public Observable<String> apply(Integer id) {
                  /* simulate making a nested async call which creates another Observable */
                  Observable<Map<String, String>> subObservable = null;
                  if (id == 1) {
                      Map<String, String> m1 = getMap("One");
                      Map<String, String> m2 = getMap("Two");
                      subObservable = Observable.just(m1, m2);
                  } else {
                      Map<String, String> m3 = getMap("Three");
                      Map<String, String> m4 = getMap("Four");
                      subObservable = Observable.just(m3, m4);
                  }
  
                  /* simulate kicking off the async call and performing a select on it to transform the data */
                  return subObservable.map(new Function<Map<String, String>, String>() {
                      @Override
                      public String apply(Map<String, String> map) {
                          return map.get("firstName");
                      }
                  });
              }
  
          });
          m.subscribe(stringObserver);
  
          verify(stringObserver, never()).onError(any(Throwable.class));
          verify(stringObserver, times(1)).onNext("OneFirst");
          verify(stringObserver, times(1)).onNext("TwoFirst");
          verify(stringObserver, times(1)).onNext("ThreeFirst");
          verify(stringObserver, times(1)).onNext("FourFirst");
          verify(stringObserver, times(1)).onComplete();
      }
  
      @Test
      public void mapMany2() {
          Map<String, String> m1 = getMap("One");
          Map<String, String> m2 = getMap("Two");
          Observable<Map<String, String>> observable1 = Observable.just(m1, m2);
  
          Map<String, String> m3 = getMap("Three");
          Map<String, String> m4 = getMap("Four");
          Observable<Map<String, String>> observable2 = Observable.just(m3, m4);
  
          Observable<Observable<Map<String, String>>> o = Observable.just(observable1, observable2);
  
          Observable<String> m = o.flatMap(new Function<Observable<Map<String, String>>, Observable<String>>() {
  
              @Override
              public Observable<String> apply(Observable<Map<String, String>> o) {
                  return o.map(new Function<Map<String, String>, String>() {
  
                      @Override
                      public String apply(Map<String, String> map) {
                          return map.get("firstName");
                      }
                  });
              }
  
          });
          m.subscribe(stringObserver);
  
          verify(stringObserver, never()).onError(any(Throwable.class));
          verify(stringObserver, times(1)).onNext("OneFirst");
          verify(stringObserver, times(1)).onNext("TwoFirst");
          verify(stringObserver, times(1)).onNext("ThreeFirst");
          verify(stringObserver, times(1)).onNext("FourFirst");
          verify(stringObserver, times(1)).onComplete();
  
      }
  
      @Test
      public void mapWithError() {
          Observable<String> w = Observable.just("one", "fail", "two", "three", "fail");
          Observable<String> m = w.map(new Function<String, String>() {
              @Override
              public String apply(String s) {
                  if ("fail".equals(s)) {
                      throw new RuntimeException("Forced Failure");
                  }
                  return s;
              }
          }).doOnError(new Consumer<Throwable>() {
  
              @Override
              public void accept(Throwable t1) {
                  t1.printStackTrace();
              }
  
          });
  
          m.subscribe(stringObserver);
          verify(stringObserver, times(1)).onNext("one");
          verify(stringObserver, never()).onNext("two");
          verify(stringObserver, never()).onNext("three");
          verify(stringObserver, never()).onComplete();
          verify(stringObserver, times(1)).onError(any(Throwable.class));
      }
  
      @Test(expected = IllegalArgumentException.class)
      public void mapWithIssue417() {
          Observable.just(1).observeOn(Schedulers.computation())
                  .map(new Function<Integer, Integer>() {
                      @Override
                      public Integer apply(Integer arg0) {
                          throw new IllegalArgumentException("any error");
                      }
                  }).blockingSingle();
      }
  
      @Test(expected = IllegalArgumentException.class)
      public void mapWithErrorInFuncAndThreadPoolScheduler() throws InterruptedException {
          // The error will throw in one of threads in the thread pool.
          // If map does not handle it, the error will disappear.
          // so map needs to handle the error by itself.
          Observable<String> m = Observable.just("one")
                  .observeOn(Schedulers.computation())
                  .map(new Function<String, String>() {
                      @Override
                      public String apply(String arg0) {
                          throw new IllegalArgumentException("any error");
                      }
                  });
  
          // block for response, expecting exception thrown
          m.blockingLast();
      }
  
      /**
       * While mapping over range(1,0).last() we expect NoSuchElementException since the sequence is empty.
       */
      @Test
      public void errorPassesThruMap() {
          assertNull(Observable.range(1, 0).lastElement().map(new Function<Integer, Integer>() {
  
              @Override
              public Integer apply(Integer i) {
                  return i;
              }
  
          }).blockingGet());
      }
  
      /**
       * We expect IllegalStateException to pass thru map.
       */
      @Test(expected = IllegalStateException.class)
      public void errorPassesThruMap2() {
          Observable.error(new IllegalStateException()).map(new Function<Object, Object>() {
  
              @Override
              public Object apply(Object i) {
                  return i;
              }
  
          }).blockingSingle();
      }
  
      /**
       * We expect an ArithmeticException exception here because last() emits a single value
       * but then we divide by 0.
       */
      @Test(expected = ArithmeticException.class)
      public void mapWithErrorInFunc() {
          Observable.range(1, 1).lastElement().map(new Function<Integer, Integer>() {
  
              @Override
              public Integer apply(Integer i) {
                  return i / 0;
              }
  
          }).blockingGet();
      }
  
      // FIXME RS subscribers can't throw
  //    @Test(expected = OnErrorNotImplementedException.class)
  //    public void verifyExceptionIsThrownIfThereIsNoExceptionHandler() {
  //
  //        ObservableSource<Object> creator = new ObservableSource<Object>() {
  //
  //            @Override
  //            public void subscribeActual(Observer<? super Object> observer) {
  //                observer.onSubscribe(EmptyDisposable.INSTANCE);
  //                observer.onNext("a");
  //                observer.onNext("b");
  //                observer.onNext("c");
  //                observer.onComplete();
  //            }
  //        };
  //
  //        Function<Object, Observable<Object>> manyMapper = new Function<Object, Observable<Object>>() {
  //
  //            @Override
  //            public Observable<Object> apply(Object object) {
  //                return Observable.just(object);
  //            }
  //        };
  //
  //        Function<Object, Object> mapper = new Function<Object, Object>() {
  //            private int count = 0;
  //
  //            @Override
  //            public Object apply(Object object) {
  //                ++count;
  //                if (count > 2) {
  //                    throw new RuntimeException();
  //                }
  //                return object;
  //            }
  //        };
  //
  //        Consumer<Object> onNext = new Consumer<Object>() {
  //
  //            @Override
  //            public void accept(Object object) {
  //                System.out.println(object.toString());
  //            }
  //        };
  //
  //        try {
  //            Observable.unsafeCreate(creator).flatMap(manyMapper).map(mapper).subscribe(onNext);
  //        } catch (RuntimeException e) {
  //            e.printStackTrace();
  //            throw e;
  //        }
  //    }
  
      private static Map<String, String> getMap(String prefix) {
          Map<String, String> m = new HashMap<>();
          m.put("firstName", prefix + "First");
          m.put("lastName", prefix + "Last");
          return m;
      }
  
      // FIXME RS subscribers can't throw
  //    @Test(expected = OnErrorNotImplementedException.class)
  //    public void testShouldNotSwallowOnErrorNotImplementedException() {
  //        Observable.just("a", "b").flatMap(new Function<String, Observable<String>>() {
  //            @Override
  //            public Observable<String> apply(String s) {
  //                return Observable.just(s + "1", s + "2");
  //            }
  //        }).flatMap(new Function<String, Observable<String>>() {
  //            @Override
  //            public Observable<String> apply(String s) {
  //                return Observable.error(new Exception("test"));
  //            }
  //        }).forEach(new Consumer<String>() {
  //            @Override
  //            public void accept(String s) {
  //                System.out.println(s);
  //            }
  //        });
  //    }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(Observable.range(1, 5).map(Functions.identity()));
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeObservable(new Function<Observable<Object>, ObservableSource<Object>>() {
              @Override
              public ObservableSource<Object> apply(Observable<Object> o) throws Exception {
                  return o.map(Functions.identity());
              }
          });
      }
  
      @Test
      public void fusedSync() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          Observable.range(1, 5)
          .map(Functions.<Integer>identity())
          .subscribe(to);
  
          to.assertFusionMode(QueueFuseable.SYNC)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void fusedAsync() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us
          .map(Functions.<Integer>identity())
          .subscribe(to);
  
          TestHelper.emit(us, 1, 2, 3, 4, 5);
  
          to.assertFusionMode(QueueFuseable.ASYNC)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void fusedReject() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY | QueueFuseable.BOUNDARY);
  
          Observable.range(1, 5)
          .map(Functions.<Integer>identity())
          .subscribe(to);
  
          to.assertFusionMode(QueueFuseable.NONE)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void badSource() {
          TestHelper.checkBadSourceObservable(new Function<Observable<Object>, Object>() {
              @Override
              public Object apply(Observable<Object> o) throws Exception {
                  return o.map(Functions.identity());
              }
          }, false, 1, 1, 1);
      }
  }
  