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.Serdes;
  
  import org.junit.jupiter.api.Test;
  
  import java.nio.ByteBuffer;
  
  import static org.hamcrest.CoreMatchers.nullValue;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.core.Is.is;
  
  public class FullChangeSerdeTest {
      private final FullChangeSerde<String> serde = FullChangeSerde.wrap(Serdes.String());
  
      /**
       * We used to serialize a Change into a single byte[]. Now, we don't anymore, but we still keep this logic here
       * so that we can produce the legacy format to test that we can still deserialize it.
       */
      private static byte[] mergeChangeArraysIntoSingleLegacyFormattedArray(final Change<byte[]> serialChange) {
          if (serialChange == null) {
              return null;
          }
  
          final int oldSize = serialChange.oldValue == null ? -1 : serialChange.oldValue.length;
          final int newSize = serialChange.newValue == null ? -1 : serialChange.newValue.length;
  
          final ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES * 2 + Math.max(0, oldSize) + Math.max(0, newSize));
  
  
          buffer.putInt(oldSize);
          if (serialChange.oldValue != null) {
              buffer.put(serialChange.oldValue);
          }
  
          buffer.putInt(newSize);
          if (serialChange.newValue != null) {
              buffer.put(serialChange.newValue);
          }
          return buffer.array();
      }
  
      @Test
      public void shouldRoundTripNull() {
          assertThat(serde.serializeParts(null, null), nullValue());
          assertThat(mergeChangeArraysIntoSingleLegacyFormattedArray(null), nullValue());
          assertThat(FullChangeSerde.decomposeLegacyFormattedArrayIntoChangeArrays(null), nullValue());
          assertThat(serde.deserializeParts(null, null), nullValue());
      }
  
  
      @Test
      public void shouldRoundTripNullChange() {
          assertThat(
              serde.serializeParts(null, new Change<>(null, null)),
              is(new Change<byte[]>(null, null))
          );
  
          assertThat(
              serde.deserializeParts(null, new Change<>(null, null)),
              is(new Change<String>(null, null))
          );
  
          final byte[] legacyFormat = mergeChangeArraysIntoSingleLegacyFormattedArray(new Change<>(null, null));
          assertThat(
              FullChangeSerde.decomposeLegacyFormattedArrayIntoChangeArrays(legacyFormat),
              is(new Change<byte[]>(null, null))
          );
      }
  
      @Test
      public void shouldRoundTripOldNull() {
          final Change<byte[]> serialized = serde.serializeParts(null, new Change<>("new", null));
          final byte[] legacyFormat = mergeChangeArraysIntoSingleLegacyFormattedArray(serialized);
          final Change<byte[]> decomposedLegacyFormat = FullChangeSerde.decomposeLegacyFormattedArrayIntoChangeArrays(legacyFormat);
          assertThat(
              serde.deserializeParts(null, decomposedLegacyFormat),
              is(new Change<>("new", null))
          );
      }
  
      @Test
      public void shouldRoundTripNewNull() {
          final Change<byte[]> serialized = serde.serializeParts(null, new Change<>(null, "old"));
          final byte[] legacyFormat = mergeChangeArraysIntoSingleLegacyFormattedArray(serialized);
          final Change<byte[]> decomposedLegacyFormat = FullChangeSerde.decomposeLegacyFormattedArrayIntoChangeArrays(legacyFormat);
          assertThat(
              serde.deserializeParts(null, decomposedLegacyFormat),
              is(new Change<>(null, "old"))
          );
      }
  
      @Test
      public void shouldRoundTripChange() {
          final Change<byte[]> serialized = serde.serializeParts(null, new Change<>("new", "old"));
          final byte[] legacyFormat = mergeChangeArraysIntoSingleLegacyFormattedArray(serialized);
          final Change<byte[]> decomposedLegacyFormat = FullChangeSerde.decomposeLegacyFormattedArrayIntoChangeArrays(legacyFormat);
          assertThat(
              serde.deserializeParts(null, decomposedLegacyFormat),
              is(new Change<>("new", "old"))
          );
      }
  }
  