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.transforms;
  
  import static org.apache.beam.sdk.transforms.display.DisplayDataMatchers.hasDisplayItem;
  import static org.apache.beam.sdk.values.TypeDescriptors.integers;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.empty;
  import static org.hamcrest.Matchers.hasSize;
  import static org.junit.Assert.assertEquals;
  
  import java.io.Serializable;
  import org.apache.beam.sdk.testing.NeedsRunner;
  import org.apache.beam.sdk.testing.PAssert;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.transforms.display.DisplayData;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionList;
  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.experimental.categories.Category;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link PTransform} base class. */
  @RunWith(JUnit4.class)
  public class PTransformTest implements Serializable {
  
    @Rule public final transient TestPipeline pipeline = TestPipeline.create();
  
    @Test
    public void testPopulateDisplayDataDefaultBehavior() {
      PTransform<PCollection<String>, PCollection<String>> transform =
          new PTransform<PCollection<String>, PCollection<String>>() {
            @Override
            public PCollection<String> expand(PCollection<String> begin) {
              throw new IllegalArgumentException("Should never be applied");
            }
          };
      DisplayData displayData = DisplayData.from(transform);
      assertThat(displayData.items(), empty());
    }
  
    @Test
    public void testSetDisplayData() {
      PTransform<PCollection<String>, PCollection<String>> transform =
          new PTransform<PCollection<String>, PCollection<String>>() {
            @Override
            public PCollection<String> expand(PCollection<String> begin) {
              throw new IllegalArgumentException("Should never be applied");
            }
          };
      transform.setDisplayData(
          ImmutableList.of(DisplayData.item("key1", "value1"), DisplayData.item("key2", 2L)));
  
      final DisplayData displayData = DisplayData.from(transform);
      assertThat(displayData.items(), hasSize(2));
      assertThat(displayData, hasDisplayItem("key1", "value1"));
      assertThat(displayData, hasDisplayItem("key2", 2L));
    }
  
    @Test
    public void testNamedCompose() {
      PTransform<PCollection<Integer>, PCollection<Integer>> composed =
          PTransform.compose("MyName", (PCollection<Integer> numbers) -> numbers);
      assertEquals("MyName", composed.name);
    }
  
    @Test
    @Category(NeedsRunner.class)
    public void testComposeBasicSerializableFunction() throws Exception {
      PCollection<Integer> output =
          pipeline
              .apply(Create.of(1, 2, 3))
              .apply(
                  PTransform.compose(
                      (PCollection<Integer> numbers) -> {
                        PCollection<Integer> inverted =
                            numbers.apply(MapElements.into(integers()).via(input -> -input));
                        return PCollectionList.of(numbers)
                            .and(inverted)
                            .apply(Flatten.pCollections());
                      }));
  
      PAssert.that(output).containsInAnyOrder(-2, -1, -3, 2, 1, 3);
      pipeline.run();
    }
  }
  