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.common.message;
  
  import org.apache.kafka.common.protocol.ByteBufferAccessor;
  import org.apache.kafka.common.protocol.MessageUtil;
  import org.apache.kafka.common.protocol.ObjectSerializationCache;
  
  import org.junit.jupiter.api.Test;
  
  import java.nio.ByteBuffer;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  public class NullableStructMessageTest {
  
      @Test
      public void testDefaultValues() {
          NullableStructMessageData message = new NullableStructMessageData();
          assertNull(message.nullableStruct);
          assertEquals(new NullableStructMessageData.MyStruct2(), message.nullableStruct2);
          assertNull(message.nullableStruct3);
          assertEquals(new NullableStructMessageData.MyStruct4(), message.nullableStruct4);
  
          message = roundTrip(message, (short) 2);
          assertNull(message.nullableStruct);
          assertEquals(new NullableStructMessageData.MyStruct2(), message.nullableStruct2);
          assertNull(message.nullableStruct3);
          assertEquals(new NullableStructMessageData.MyStruct4(), message.nullableStruct4);
      }
  
      @Test
      public void testRoundTrip() {
          NullableStructMessageData message = new NullableStructMessageData()
              .setNullableStruct(new NullableStructMessageData.MyStruct()
                  .setMyInt(1)
                  .setMyString("1"))
              .setNullableStruct2(new NullableStructMessageData.MyStruct2()
                  .setMyInt(2)
                  .setMyString("2"))
              .setNullableStruct3(new NullableStructMessageData.MyStruct3()
                  .setMyInt(3)
                  .setMyString("3"))
              .setNullableStruct4(new NullableStructMessageData.MyStruct4()
                  .setMyInt(4)
                  .setMyString("4"));
  
          NullableStructMessageData newMessage = roundTrip(message, (short) 2);
          assertEquals(message, newMessage);
      }
  
      @Test
      public void testNullForAllFields() {
          NullableStructMessageData message = new NullableStructMessageData()
              .setNullableStruct(null)
              .setNullableStruct2(null)
              .setNullableStruct3(null)
              .setNullableStruct4(null);
  
          message = roundTrip(message, (short) 2);
          assertNull(message.nullableStruct);
          assertNull(message.nullableStruct2);
          assertNull(message.nullableStruct3);
          assertNull(message.nullableStruct4);
      }
  
      @Test
      public void testNullableStruct2CanNotBeNullInVersion0() {
          NullableStructMessageData message = new NullableStructMessageData()
              .setNullableStruct2(null);
  
          assertThrows(NullPointerException.class, () -> roundTrip(message, (short) 0));
      }
  
      @Test
      public void testToStringWithNullStructs() {
          NullableStructMessageData message = new NullableStructMessageData()
              .setNullableStruct(null)
              .setNullableStruct2(null)
              .setNullableStruct3(null)
              .setNullableStruct4(null);
  
          message.toString();
      }
  
      /**
       * Regression test for KAFKA-18199. Tests that the size of the varint encoding a tagged nullable
       * struct's size is calculated correctly.
       */
      @Test
      public void testTaggedStructSize() {
          NullableStructMessageData message = new NullableStructMessageData()
              .setNullableStruct(null)
              .setNullableStruct2(null)
              .setNullableStruct3(null)
              .setNullableStruct4(new NullableStructMessageData.MyStruct4()
                  .setMyInt(4)
                  .setMyString(new String(new char[121])));
  
          // We want the struct to be 127 bytes long, so that the varint encoding of its size is one
          // short of overflowing into a two-byte representation. An extra byte is added to the
          // nullable struct size to account for the is-not-null flag.
          assertEquals(127, message.nullableStruct4().size(new ObjectSerializationCache(), (short) 2));
  
          NullableStructMessageData newMessage = roundTrip(message, (short) 2);
          assertEquals(message, newMessage);
      }
  
      private NullableStructMessageData deserialize(ByteBuffer buf, short version) {
          NullableStructMessageData message = new NullableStructMessageData();
          message.read(new ByteBufferAccessor(buf.duplicate()), version);
          return message;
      }
  
      private ByteBuffer serialize(NullableStructMessageData message, short version) {
          return MessageUtil.toByteBufferAccessor(message, version).buffer();
      }
  
      private NullableStructMessageData roundTrip(NullableStructMessageData message, short version) {
          ByteBuffer buffer = serialize(message, version);
          // Check size calculation
          assertEquals(buffer.remaining(), message.size(new ObjectSerializationCache(), version));
          return deserialize(buffer.duplicate(), version);
      }
  }
  