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.util;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.withSettings;
  
  import java.io.ByteArrayOutputStream;
  import java.io.NotSerializableException;
  import java.io.ObjectOutputStream;
  import java.util.List;
  import org.apache.beam.sdk.state.StateContexts;
  import org.apache.beam.sdk.transforms.CombineWithContext.CombineFnWithContext;
  import org.apache.beam.sdk.transforms.CombineWithContext.Context;
  import org.apache.beam.sdk.transforms.Sum;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Unit tests for {@link CombineFnUtil}. */
  @RunWith(JUnit4.class)
  public class CombineFnUtilTest {
  
    @Rule public ExpectedException expectedException = ExpectedException.none();
  
    CombineFnWithContext<Integer, Integer, Integer> mockCombineFn;
  
    @SuppressWarnings("unchecked")
    @Before
    public void setUp() {
      mockCombineFn = mock(CombineFnWithContext.class, withSettings().serializable());
    }
  
    @Test
    public void testNonSerializable() throws Exception {
      expectedException.expect(NotSerializableException.class);
      expectedException.expectMessage(
          "Cannot serialize the CombineFn resulting from CombineFnUtil.bindContext.");
  
      ByteArrayOutputStream buffer = new ByteArrayOutputStream();
      ObjectOutputStream oos = new ObjectOutputStream(buffer);
      oos.writeObject(CombineFnUtil.bindContext(mockCombineFn, StateContexts.nullContext()));
    }
  
    @Test
    public void testToFnWithContextIdempotent() throws Exception {
      CombineFnWithContext<Integer, int[], Integer> fnWithContext =
          CombineFnUtil.toFnWithContext(Sum.ofIntegers());
      assertTrue(fnWithContext == CombineFnUtil.toFnWithContext(fnWithContext));
    }
  
    @Test
    public void testToFnWithContext() throws Exception {
      CombineFnWithContext<Integer, int[], Integer> fnWithContext =
          CombineFnUtil.toFnWithContext(Sum.ofIntegers());
      List<Integer> inputs = ImmutableList.of(1, 2, 3, 4);
      Context nullContext = CombineContextFactory.nullContext();
      int[] accum = fnWithContext.createAccumulator(nullContext);
      for (Integer i : inputs) {
        accum = fnWithContext.addInput(accum, i, nullContext);
      }
      assertEquals(10, fnWithContext.extractOutput(accum, nullContext).intValue());
    }
  }
  