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.runners.dataflow.worker;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  
  import com.google.api.services.dataflow.model.Source;
  import java.io.IOException;
  import java.util.NoSuchElementException;
  import org.apache.beam.runners.dataflow.util.CloudObject;
  import org.apache.beam.runners.dataflow.util.CloudObjects;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.NativeReader;
  import org.apache.beam.sdk.coders.BigEndianIntegerCoder;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.StringUtf8Coder;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.sdk.values.WindowedValues;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.hamcrest.CoreMatchers;
  import org.hamcrest.core.IsInstanceOf;
  import org.junit.Assert;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for ReaderFactory. */
  @RunWith(JUnit4.class)
  @SuppressWarnings({
    "rawtypes", // TODO(https://github.com/apache/beam/issues/20447)
  })
  public class ReaderFactoryTest {
  
    static class TestReaderFactory implements ReaderFactory {
      @Override
      public NativeReader<?> create(
          CloudObject spec,
          @Nullable Coder<?> coder,
          @Nullable PipelineOptions options,
          @Nullable DataflowExecutionContext executionContext,
          DataflowOperationContext operationContext) {
        return new TestReader();
      }
    }
  
    static class TestReader extends NativeReader<Integer> {
      @Override
      public NativeReaderIterator<Integer> iterator() {
        return new TestReaderIterator();
      }
  
      /** A source iterator that produces no values, for testing. */
      static class TestReaderIterator extends NativeReaderIterator<Integer> {
        @Override
        public boolean start() {
          return false;
        }
  
        @Override
        public boolean advance() {
          return false;
        }
  
        @Override
        public Integer getCurrent() {
          throw new NoSuchElementException();
        }
      }
    }
  
    static class SingletonTestReaderFactory implements ReaderFactory {
      @Override
      public NativeReader<?> create(
          CloudObject spec,
          @Nullable Coder<?> coder,
          @Nullable PipelineOptions options,
          @Nullable DataflowExecutionContext executionContext,
          DataflowOperationContext operationContext) {
        return new SingletonTestReader();
      }
    }
  
    static class SingletonTestReader extends NativeReader<WindowedValue<String>> {
      @Override
      public SingletonTestReaderIterator iterator() {
        return new SingletonTestReaderIterator();
      }
  
      /** A source iterator that produces no values, for testing. */
      static class SingletonTestReaderIterator extends NativeReaderIterator<WindowedValue<String>> {
        @Override
        public boolean start() {
          return true;
        }
  
        @Override
        public boolean advance() throws IOException {
          return false;
        }
  
        @Override
        public WindowedValue<String> getCurrent() {
          return WindowedValues.valueInGlobalWindow("something");
        }
      }
    }
  
    @Test
    public void testCreateReader() throws Exception {
      CloudObject spec = CloudObject.forClass(TestReaderFactory.class);
  
      Source cloudSource = new Source();
      cloudSource.setSpec(spec);
      cloudSource.setCodec(
          CloudObjects.asCloudObject(BigEndianIntegerCoder.of(), /*sdkComponents=*/ null));
  
      PipelineOptions options = PipelineOptionsFactory.create();
      ReaderRegistry registry =
          ReaderRegistry.defaultRegistry()
              .register(TestReaderFactory.class.getName(), new TestReaderFactory());
      NativeReader<?> reader =
          registry.create(
              cloudSource,
              PipelineOptionsFactory.create(),
              BatchModeExecutionContext.forTesting(options, "testStage"),
              null);
      assertThat(reader, new IsInstanceOf(TestReader.class));
    }
  
    @Test
    public void testCreateUnknownReader() throws Exception {
      CloudObject spec = CloudObject.forClassName("UnknownSource");
      Source cloudSource = new Source();
      cloudSource.setSpec(spec);
      cloudSource.setCodec(CloudObjects.asCloudObject(StringUtf8Coder.of(), /*sdkComponents=*/ null));
      try {
        PipelineOptions options = PipelineOptionsFactory.create();
        ReaderRegistry.defaultRegistry()
            .create(
                cloudSource,
                options,
                BatchModeExecutionContext.forTesting(options, "testStage"),
                null);
        Assert.fail("should have thrown an exception");
      } catch (Exception exn) {
        assertThat(exn.toString(), CoreMatchers.containsString("Unable to create a Reader"));
      }
    }
  }
  