content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.kafka.streams.kstream.internals;
  
  import org.apache.kafka.common.serialization.IntegerSerializer;
  import org.apache.kafka.common.serialization.Serdes;
  import org.apache.kafka.common.serialization.StringSerializer;
  import org.apache.kafka.streams.StreamsBuilder;
  import org.apache.kafka.streams.TestInputTopic;
  import org.apache.kafka.streams.TopologyTestDriver;
  import org.apache.kafka.streams.kstream.Consumed;
  import org.apache.kafka.streams.kstream.KStream;
  import org.apache.kafka.streams.kstream.ValueTransformerWithKeySupplier;
  import org.apache.kafka.streams.kstream.internals.graph.ProcessorGraphNode;
  import org.apache.kafka.streams.kstream.internals.graph.ProcessorParameters;
  import org.apache.kafka.streams.processor.api.ContextualProcessor;
  import org.apache.kafka.streams.processor.api.Processor;
  import org.apache.kafka.streams.processor.api.ProcessorSupplier;
  import org.apache.kafka.streams.processor.api.Record;
  import org.apache.kafka.test.MockApiProcessorSupplier;
  import org.apache.kafka.test.NoopValueTransformerWithKey;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.extension.ExtendWith;
  import org.mockito.junit.jupiter.MockitoExtension;
  import org.mockito.junit.jupiter.MockitoSettings;
  import org.mockito.quality.Strictness;
  
  import java.util.Random;
  
  import static org.junit.jupiter.api.Assertions.assertTrue;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.when;
  
  @ExtendWith(MockitoExtension.class)
  @MockitoSettings(strictness = Strictness.STRICT_STUBS)
  public class AbstractStreamTest {
  
      @Test
      public void testToInternalValueTransformerWithKeySupplierSuppliesNewTransformers() {
          final ValueTransformerWithKeySupplier<?, ?, ?> valueTransformerWithKeySupplier =
              mock(ValueTransformerWithKeySupplier.class);
          when(valueTransformerWithKeySupplier.get()).thenReturn(new NoopValueTransformerWithKey<>());
          valueTransformerWithKeySupplier.get();
          valueTransformerWithKeySupplier.get();
          valueTransformerWithKeySupplier.get();
      }
  
      @Test
      public void testShouldBeExtensible() {
          final StreamsBuilder builder = new StreamsBuilder();
          final int[] expectedKeys = new int[]{1, 2, 3, 4, 5, 6, 7};
          final MockApiProcessorSupplier<Integer, String, Void, Void> supplier = new MockApiProcessorSupplier<>();
          final String topicName = "topic";
  
          final ExtendedKStream<Integer, String> stream = new ExtendedKStream<>(builder.stream(topicName, Consumed.with(Serdes.Integer(), Serdes.String())));
  
          stream.randomFilter().process(supplier);
  
          try (final TopologyTestDriver driver = new TopologyTestDriver(builder.build())) {
  
              final TestInputTopic<Integer, String> inputTopic = driver.createInputTopic(topicName, new IntegerSerializer(), new StringSerializer());
              for (final int expectedKey : expectedKeys) {
                  inputTopic.pipeInput(expectedKey, "V" + expectedKey);
              }
  
              assertTrue(supplier.theCapturedProcessor().processed().size() <= expectedKeys.length);
          }
      }
  
      private static class ExtendedKStream<K, V> extends AbstractStream<K, V> {
  
          ExtendedKStream(final KStream<K, V> stream) {
              super((KStreamImpl<K, V>) stream);
          }
  
          KStream<K, V> randomFilter() {
              final String name = builder.newProcessorName("RANDOM-FILTER-");
              final ProcessorGraphNode<K, V> processorNode = new ProcessorGraphNode<>(
                  name,
                  new ProcessorParameters<>(new ExtendedKStreamDummy<>(), name));
              builder.addGraphNode(this.graphNode, processorNode);
              return new KStreamImpl<>(name, null, null, subTopologySourceNodes, false, processorNode, builder);
          }
      }
  
      private static class ExtendedKStreamDummy<K, V> implements ProcessorSupplier<K, V, K, V> {
  
          private final Random rand;
  
          ExtendedKStreamDummy() {
              rand = new Random();
          }
  
          @Override
          public Processor<K, V, K, V> get() {
              return new ExtendedKStreamDummyProcessor();
          }
  
          private class ExtendedKStreamDummyProcessor extends ContextualProcessor<K, V, K, V> {
              @Override
              public void process(final Record<K, V> record) {
                  // flip a coin and filter
                  if (rand.nextBoolean()) {
                      context().forward(record);
                  }
              }
          }
      }
  }
  