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.
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  package org.apache.beam.sdk.transforms;
  
  import java.util.ArrayList;
  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.testing.UsesImpulse;
  import org.apache.beam.sdk.testing.UsesStatefulParDo;
  import org.apache.beam.sdk.testing.UsesUnboundedPCollections;
  import org.apache.beam.sdk.testing.UsesUnboundedSplittableParDo;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.joda.time.Duration;
  import org.joda.time.Instant;
  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 PeriodicImpulse. */
  @RunWith(JUnit4.class)
  public class PeriodicImpulseTest {
    @Rule public transient TestPipeline p = TestPipeline.create();
  
    public static class ExtractTsDoFn<InputT> extends DoFn<InputT, KV<InputT, Instant>> {
      @ProcessElement
      public void processElement(DoFn<InputT, KV<InputT, Instant>>.ProcessContext c)
          throws Exception {
        c.output(KV.of(c.element(), c.timestamp()));
      }
    }
  
    @Test
    @Category({
      NeedsRunner.class,
      UsesImpulse.class,
      UsesStatefulParDo.class,
      UsesUnboundedPCollections.class,
      UsesUnboundedSplittableParDo.class
    })
    public void testOutputsProperElements() {
      Instant instant = Instant.now();
  
      Instant startTime = instant.minus(Duration.standardHours(100));
      long duration = 500;
      Duration interval = Duration.millis(250);
      long intervalMillis = interval.getMillis();
      Instant stopTime = startTime.plus(Duration.millis(duration));
  
      PCollection<KV<Instant, Instant>> result =
          p.apply(PeriodicImpulse.create().startAt(startTime).stopAt(stopTime).withInterval(interval))
              .apply(ParDo.of(new ExtractTsDoFn<>()));
  
      ArrayList<KV<Instant, Instant>> expectedResults =
          new ArrayList<>((int) (duration / intervalMillis + 1));
      for (long i = 0; i <= duration; i += intervalMillis) {
        Instant el = startTime.plus(Duration.millis(i));
        expectedResults.add(KV.of(el, el));
      }
  
      PAssert.that(result).containsInAnyOrder(expectedResults);
  
      p.run().waitUntilFinish();
    }
  }
  