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.testing;
  
  import java.util.ArrayList;
  import java.util.List;
  import org.apache.beam.sdk.annotations.Internal;
  import org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.transforms.windowing.PaneInfo;
  import org.apache.beam.sdk.values.OutputBuilder;
  import org.apache.beam.sdk.values.WindowedValues;
  import org.joda.time.Instant;
  
  /**
   * An implementation of {@link DoFn.OutputReceiver} that naively collects all output values.
   *
   * <p>Because this API is crude and not designed to be very general, it is for internal use only and
   * will be changed arbitrarily.
   */
  @Internal
  public class TestOutputReceiver<T> implements DoFn.OutputReceiver<T> {
    private final List<T> records = new ArrayList<>();
  
    // To simplify testing of a DoFn, we want to be able to collect their outputs even
    // when no window is provided (because processElement is called with only a value in testing).
    private static final BoundedWindow fakeWindow =
        new BoundedWindow() {
          @Override
          public Instant maxTimestamp() {
            return BoundedWindow.TIMESTAMP_MIN_VALUE;
          }
        };
  
    @Override
    public OutputBuilder<T> builder(T value) {
      return WindowedValues.<T>builder()
          .setValue(value)
          .setWindow(fakeWindow)
          .setPaneInfo(PaneInfo.NO_FIRING)
          .setTimestamp(BoundedWindow.TIMESTAMP_MIN_VALUE)
          .setReceiver(windowedValue -> records.add(windowedValue.getValue()));
    }
  
    public List<T> getOutputs() {
      return records;
    }
  }
  