samza-core/src/test/java/org/apache/samza/operators/impl/TestFlatmapOperatorImpl.java

/*
 * 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,
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package org.apache.samza.operators.impl;

import org.apache.samza.operators.data.TestMessageEnvelope;
import org.apache.samza.operators.data.TestOutputMessageEnvelope;
import org.apache.samza.operators.functions.FlatMapFunction;
import org.apache.samza.operators.spec.StreamOperatorSpec;
import org.apache.samza.task.MessageCollector;
import org.apache.samza.task.TaskCoordinator;
import org.junit.Test;

import java.util.Collection;

import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;


public class TestFlatmapOperatorImpl {

  @Test
  @SuppressWarnings("unchecked")
  public void testStreamOperator() {
    StreamOperatorSpec<TestMessageEnvelope, TestOutputMessageEnvelope> mockOp = mock(StreamOperatorSpec.class);
    FlatMapFunction<TestMessageEnvelope, TestOutputMessageEnvelope> txfmFn = mock(FlatMapFunction.class);
    when(mockOp.getTransformFn()).thenReturn(txfmFn);
    FlatmapOperatorImpl<TestMessageEnvelope, TestOutputMessageEnvelope> opImpl =
        new FlatmapOperatorImpl<>(mockOp);
    TestMessageEnvelope inMsg = mock(TestMessageEnvelope.class);
    Collection<TestOutputMessageEnvelope> mockOutputs = mock(Collection.class);
    when(txfmFn.apply(inMsg)).thenReturn(mockOutputs);
    MessageCollector mockCollector = mock(MessageCollector.class);
    TaskCoordinator mockCoordinator = mock(TaskCoordinator.class);
    Collection<TestOutputMessageEnvelope> results = opImpl
        .handleMessage(inMsg, mockCollector, mockCoordinator);
    verify(txfmFn, times(1)).apply(inMsg);
    assertEquals(results, mockOutputs);
  }

  @Test
  public void testStreamOperatorClose() {
    StreamOperatorSpec<TestMessageEnvelope, TestOutputMessageEnvelope> mockOp = mock(StreamOperatorSpec.class);
    FlatMapFunction<TestMessageEnvelope, TestOutputMessageEnvelope> txfmFn = mock(FlatMapFunction.class);
    when(mockOp.getTransformFn()).thenReturn(txfmFn);

    FlatmapOperatorImpl<TestMessageEnvelope, TestOutputMessageEnvelope> opImpl =
        new FlatmapOperatorImpl<>(mockOp);

    // ensure that close is not called yet
    verify(txfmFn, times(0)).close();
    opImpl.handleClose();
    // ensure that close is called once inside handleClose()
    verify(txfmFn, times(1)).close();
  }
}