/*
 * 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.beam.sdk.coders;

import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertThat;

import org.apache.beam.sdk.values.TypeDescriptor;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Test case for {@link VoidCoder}. */
@RunWith(JUnit4.class)
public class VoidCoderTest {
  private static final Coder<Void> TEST_CODER = VoidCoder.of();

  @Test
  public void testEncodedTypeDescriptor() throws Exception {
    assertThat(TEST_CODER.getEncodedTypeDescriptor(), equalTo(TypeDescriptor.of(Void.class)));
  }

  @Test
  public void testStructuralValueSharesSameObject() {
    assertEquals(TEST_CODER.structuralValue(null), TEST_CODER.structuralValue(null));
    // This is a minor performance optimization to not encode and compare empty byte
    // arrays.
    assertSame(TEST_CODER.structuralValue(null), TEST_CODER.structuralValue(null));
  }
}
