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.beam.sdk.coders;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkArgument;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.equalTo;
  import static org.hamcrest.Matchers.theInstance;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import org.apache.beam.sdk.coders.Coder.Context;
  import org.apache.beam.sdk.testing.CoderProperties;
  import org.apache.beam.sdk.transforms.windowing.GlobalWindow;
  import org.apache.beam.sdk.values.TypeDescriptor;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Unit tests for {@link NullableCoder}. */
  @RunWith(JUnit4.class)
  public class NullableCoderTest {
  
    private static final Coder<String> TEST_CODER = NullableCoder.of(StringUtf8Coder.of());
  
    private static final List<String> TEST_VALUES =
        Arrays.asList(
            "",
            "a",
            "13",
            "hello",
            null,
            "a longer string with spaces and all that",
            "a string with a \n newline",
            "スタリング");
  
    @Test
    public void testDecodeEncodeContentsInSameOrder() throws Exception {
      for (String value : TEST_VALUES) {
        CoderProperties.coderDecodeEncodeEqual(TEST_CODER, value);
      }
    }
  
    @Test
    public void testCoderSerializable() throws Exception {
      CoderProperties.coderSerializable(TEST_CODER);
    }
  
    @Test
    public void testCoderIsSerializableWithWellKnownCoderType() throws Exception {
      CoderProperties.coderSerializable(NullableCoder.of(GlobalWindow.Coder.INSTANCE));
    }
  
    /**
     * Generated data to check that the wire format has not changed. To regenerate, see {@code
     * PrintBase64Encodings}.
     *
     * @see org.apache.beam.sdk.coders.PrintBase64Encodings
     */
    private static final List<String> TEST_ENCODINGS =
        Arrays.asList(
            "AQ",
            "AWE",
            "ATEz",
            "AWhlbGxv",
            "AA",
            "AWEgbG9uZ2VyIHN0cmluZyB3aXRoIHNwYWNlcyBhbmQgYWxsIHRoYXQ",
            "AWEgc3RyaW5nIHdpdGggYSAKIG5ld2xpbmU",
            "AeOCueOCv-ODquODs-OCsA");
  
    @Test
    public void testWireFormatEncode() throws Exception {
      CoderProperties.coderEncodesBase64(TEST_CODER, TEST_VALUES, TEST_ENCODINGS);
    }
  
    @Test
    public void testEncodedSize() throws Exception {
      NullableCoder<Double> coder = NullableCoder.of(DoubleCoder.of());
      assertEquals(1, coder.getEncodedElementByteSize(null));
      assertEquals(9, coder.getEncodedElementByteSize(5.0));
    }
  
    @Test
    public void testEncodedSizeNested() throws Exception {
      NullableCoder<String> varLenCoder = NullableCoder.of(StringUtf8Coder.of());
      assertEquals(1, varLenCoder.getEncodedElementByteSize(null));
      assertEquals(6, varLenCoder.getEncodedElementByteSize("spam"));
    }
  
    @Test
    public void testObserverIsCheap() throws Exception {
      NullableCoder<Double> coder = NullableCoder.of(DoubleCoder.of());
      assertTrue(coder.isRegisterByteSizeObserverCheap(5.0));
    }
  
    @Test
    public void testObserverIsNotCheap() throws Exception {
      NullableCoder<List<String>> coder = NullableCoder.of(ListCoder.of(StringUtf8Coder.of()));
      assertFalse(coder.isRegisterByteSizeObserverCheap(ImmutableList.of("hi", "test")));
    }
  
    @Test
    public void testObserverIsAlwaysCheapForNullValues() throws Exception {
      NullableCoder<List<String>> coder = NullableCoder.of(ListCoder.of(StringUtf8Coder.of()));
      assertTrue(coder.isRegisterByteSizeObserverCheap(null));
    }
  
    @Test
    public void testStructuralValueConsistentWithEquals() throws Exception {
      CoderProperties.structuralValueConsistentWithEquals(TEST_CODER, null, null);
    }
  
    @Rule public ExpectedException thrown = ExpectedException.none();
  
    @Test
    public void testDecodingError() throws Exception {
      thrown.expect(CoderException.class);
      thrown.expectMessage(
          equalTo("NullableCoder expects either a byte valued 0 (null) " + "or 1 (present), got 5"));
  
      InputStream input = new ByteArrayInputStream(new byte[] {5});
      TEST_CODER.decode(input, Coder.Context.OUTER);
    }
  
    @Test
    public void testSubcoderRecievesEntireStream() throws Exception {
      NullableCoder<String> coder = NullableCoder.of(new EntireStreamExpectingCoder());
  
      CoderProperties.coderDecodeEncodeEqualInContext(coder, Context.OUTER, null);
      CoderProperties.coderDecodeEncodeEqualInContext(coder, Context.OUTER, "foo");
    }
  
    @Test
    public void testNestedNullableCoder() {
      NullableCoder<Double> coder = NullableCoder.of(DoubleCoder.of());
      assertThat(NullableCoder.of(coder), theInstance(coder));
    }
  
    @Test
    public void testEncodedTypeDescriptor() throws Exception {
      assertThat(TEST_CODER.getEncodedTypeDescriptor(), equalTo(TypeDescriptor.of(String.class)));
    }
  
    private static class EntireStreamExpectingCoder extends AtomicCoder<String> {
      @Override
      public void encode(String value, OutputStream outStream) throws IOException {
        encode(value, outStream, Context.NESTED);
      }
  
      @Override
      public void encode(String value, OutputStream outStream, Context context) throws IOException {
        checkArgument(context.isWholeStream, "Expected to get entire stream");
        StringUtf8Coder.of().encode(value, outStream, context);
      }
  
      @Override
      public String decode(InputStream inStream) throws CoderException, IOException {
        return decode(inStream, Context.NESTED);
      }
  
      @Override
      public String decode(InputStream inStream, Context context) throws CoderException, IOException {
        checkArgument(context.isWholeStream, "Expected to get entire stream");
        return StringUtf8Coder.of().decode(inStream, context);
      }
  
      @Override
      public List<? extends Coder<?>> getCoderArguments() {
        return Collections.emptyList();
      }
  
      @Override
      public void verifyDeterministic() throws NonDeterministicException {}
    }
  }
  