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.values;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.containsString;
  import static org.hamcrest.Matchers.instanceOf;
  import static org.hamcrest.Matchers.not;
  
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.VarIntCoder;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.transforms.Create;
  import org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.transforms.ParDo;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link TypedPValue}, primarily focusing on Coder inference. */
  @RunWith(JUnit4.class)
  public class TypedPValueTest {
  
    @Rule public final TestPipeline p = TestPipeline.create().enableAbandonedNodeEnforcement(false);
  
    @Rule public ExpectedException thrown = ExpectedException.none();
  
    private static class IdentityDoFn extends DoFn<Integer, Integer> {
      private static final long serialVersionUID = 0;
  
      @ProcessElement
      public void processElement(ProcessContext c) throws Exception {
        c.output(c.element());
      }
    }
  
    private PCollectionTuple buildPCollectionTupleWithTags(
        TupleTag<Integer> mainOutputTag, TupleTag<Integer> additionalOutputTag) {
      PCollection<Integer> input = p.apply(Create.of(1, 2, 3));
      PCollectionTuple tuple =
          input.apply(
              ParDo.of(new IdentityDoFn())
                  .withOutputTags(mainOutputTag, TupleTagList.of(additionalOutputTag)));
      return tuple;
    }
  
    private static <T> TupleTag<T> makeTagStatically() {
      return new TupleTag<T>() {};
    }
  
    @Test
    public void testUntypedOutputTupleTagGivesActionableMessage() {
      TupleTag<Integer> mainOutputTag = new TupleTag<Integer>() {};
      // untypedOutputTag did not use anonymous subclass.
      TupleTag<Integer> untypedOutputTag = new TupleTag<>();
      PCollectionTuple tuple = buildPCollectionTupleWithTags(mainOutputTag, untypedOutputTag);
  
      thrown.expect(IllegalStateException.class);
      thrown.expectMessage("No Coder has been manually specified");
      thrown.expectMessage("Building a Coder using a registered CoderProvider failed");
  
      Coder<?> coder = tuple.get(untypedOutputTag).getCoder();
      System.out.println(coder);
    }
  
    @Test
    public void testStaticFactoryOutputTupleTagGivesActionableMessage() {
      TupleTag<Integer> mainOutputTag = new TupleTag<Integer>() {};
      // untypedOutputTag constructed from a static factory method.
      TupleTag<Integer> untypedOutputTag = makeTagStatically();
      PCollectionTuple tuple = buildPCollectionTupleWithTags(mainOutputTag, untypedOutputTag);
  
      thrown.expect(IllegalStateException.class);
      thrown.expectMessage("No Coder has been manually specified");
      thrown.expectMessage("Building a Coder using a registered CoderProvider failed");
  
      tuple.get(untypedOutputTag).getCoder();
    }
  
    @Test
    public void testTypedOutputTupleTag() {
      TupleTag<Integer> mainOutputTag = new TupleTag<Integer>() {};
      // typedOutputTag was constructed with compile-time type information.
      TupleTag<Integer> typedOutputTag = new TupleTag<Integer>() {};
      PCollectionTuple tuple = buildPCollectionTupleWithTags(mainOutputTag, typedOutputTag);
  
      assertThat(tuple.get(typedOutputTag).getCoder(), instanceOf(VarIntCoder.class));
    }
  
    @Test
    public void testUntypedMainOutputTagTypedOutputTupleTag() {
      // mainOutputTag is allowed to be untyped because Coder can be inferred other ways.
      TupleTag<Integer> mainOutputTag = new TupleTag<>();
      TupleTag<Integer> typedOutputTag = new TupleTag<Integer>() {};
      PCollectionTuple tuple = buildPCollectionTupleWithTags(mainOutputTag, typedOutputTag);
  
      assertThat(tuple.get(typedOutputTag).getCoder(), instanceOf(VarIntCoder.class));
    }
  
    /**
     * This type is incompatible with all known coder providers such as Serializable,
     * {@code @DefaultCoder} which allows testing coder registry lookup failure cases.
     */
    static class EmptyClass {}
  
    private static class EmptyClassDoFn extends DoFn<Integer, EmptyClass> {
      private static final long serialVersionUID = 0;
  
      @ProcessElement
      public void processElement(ProcessContext c) throws Exception {
        c.output(new EmptyClass());
      }
    }
  
    @Test
    public void testParDoWithNoOutputsErrorDoesNotMentionTupleTag() {
      PCollection<EmptyClass> input =
          p.apply(Create.of(1, 2, 3)).apply(ParDo.of(new EmptyClassDoFn()));
  
      thrown.expect(IllegalStateException.class);
  
      // Output specific to ParDo additional TupleTag outputs should not be present.
      thrown.expectMessage(not(containsString("erasure")));
      thrown.expectMessage(not(containsString("see TupleTag Javadoc")));
      // Instead, expect output suggesting other possible fixes.
      thrown.expectMessage("Building a Coder using a registered CoderProvider failed");
  
      input.getCoder();
    }
  
    @Test
    public void testFinishSpecifyingShouldFailIfNoCoderInferrable() {
      p.enableAbandonedNodeEnforcement(false);
      PCollection<Integer> created = p.apply(Create.of(1, 2, 3));
      ParDo.SingleOutput<Integer, EmptyClass> uninferrableParDo = ParDo.of(new EmptyClassDoFn());
      PCollection<EmptyClass> unencodable = created.apply(uninferrableParDo);
  
      thrown.expect(IllegalStateException.class);
      thrown.expectMessage("Unable to return a default Coder");
      thrown.expectMessage("Inferring a Coder from the CoderRegistry failed");
  
      unencodable.finishSpecifying(created, uninferrableParDo);
    }
  }
  