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.protocol;
  
  import org.apache.kafka.common.utils.ByteBufferOutputStream;
  
  import org.junit.jupiter.api.Test;
  
  import java.io.DataOutputStream;
  import java.nio.ByteBuffer;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  public class DataOutputStreamWritableTest {
      @Test
      public void testWritingSlicedByteBuffer() {
          byte[] expectedArray = new byte[]{2, 3, 0, 0};
          ByteBuffer sourceBuffer = ByteBuffer.wrap(new byte[]{0, 1, 2, 3});
          ByteBuffer resultBuffer = ByteBuffer.allocate(4);
  
          // Move position forward to ensure slice is not whole buffer
          sourceBuffer.position(2);
          ByteBuffer slicedBuffer = sourceBuffer.slice();
  
          Writable writable = new DataOutputStreamWritable(
                  new DataOutputStream(new ByteBufferOutputStream(resultBuffer)));
  
          writable.writeByteBuffer(slicedBuffer);
  
          assertEquals(2, resultBuffer.position(), "Writing to the buffer moves the position forward");
          assertArrayEquals(expectedArray, resultBuffer.array(), "Result buffer should have expected elements");
      }
  
      @Test
      public void testWritingSlicedByteBufferWithNonZeroPosition() {
          byte[] expectedArray = new byte[]{3, 0, 0, 0};
          ByteBuffer originalBuffer = ByteBuffer.wrap(new byte[]{0, 1, 2, 3});
          ByteBuffer resultBuffer = ByteBuffer.allocate(4);
  
          // Move position forward to ensure slice is backed by heap buffer with non-zero offset
          originalBuffer.position(2);
          ByteBuffer slicedBuffer = originalBuffer.slice();
          // Move the slice's position forward to ensure the writer starts reading at that position
          slicedBuffer.position(1);
  
          Writable writable = new DataOutputStreamWritable(
                  new DataOutputStream(new ByteBufferOutputStream(resultBuffer)));
  
          writable.writeByteBuffer(slicedBuffer);
  
          assertEquals(1, resultBuffer.position(), "Writing to the buffer moves the position forward");
          assertArrayEquals(expectedArray, resultBuffer.array(), "Result buffer should have expected elements");
      }
  }