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 java.util.Iterator;
  
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.Function;
  
  /**
   * An Iterable and Iterator that crashes with TestException after the given number
   * of method invocations on iterator(), hasNext() and next().
   * 
   * @param <T> the result type
   */
  public final class CrashingMappedIterable<T> implements Iterable<T> {
      int crashOnIterator;
  
      final int crashOnHasNext;
  
      final int crashOnNext;
  
      final Function<Integer, T> mapper;
  
      public CrashingMappedIterable(int crashOnIterator, int crashOnHasNext, int crashOnNext, Function<Integer, T> mapper) {
          this.crashOnIterator = crashOnIterator;
          this.crashOnHasNext = crashOnHasNext;
          this.crashOnNext = crashOnNext;
          this.mapper = mapper;
      }
  
      @Override
      public Iterator<T> iterator() {
          if (--crashOnIterator <= 0) {
              throw new TestException("iterator()");
          }
          return new CrashingMapperIterator<>(crashOnHasNext, crashOnNext, mapper);
      }
  
      static final class CrashingMapperIterator<T> implements Iterator<T> {
          int crashOnHasNext;
  
          int crashOnNext;
  
          int count;
  
          final Function<Integer, T> mapper;
  
          CrashingMapperIterator(int crashOnHasNext, int crashOnNext, Function<Integer, T> mapper) {
              this.crashOnHasNext = crashOnHasNext;
              this.crashOnNext = crashOnNext;
              this.mapper = mapper;
          }
  
          @Override
          public boolean hasNext() {
              if (--crashOnHasNext <= 0) {
                  throw new TestException("hasNext()");
              }
              return true;
          }
  
          @Override
          public T next() {
              if (--crashOnNext <= 0) {
                  throw new TestException("next()");
              }
              try {
                  return mapper.apply(count++);
              } catch (Throwable ex) {
                  throw ExceptionHelper.wrapOrThrow(ex);
              }
          }
  
          @Override
          public void remove() {
              throw new UnsupportedOperationException();
          }
      }
  }
  