RollingCountBoltTest.java

package storm.starter.bolt;

import static org.fest.assertions.api.Assertions.assertThat;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyZeroInteractions;
import static org.mockito.Mockito.when;

import java.util.Map;

import org.testng.annotations.Test;

import storm.starter.tools.MockTupleHelpers;
import backtype.storm.Config;
import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

public class RollingCountBoltTest {

    private static final String ANY_NON_SYSTEM_COMPONENT_ID = "irrelevant_component_id";
    private static final String ANY_NON_SYSTEM_STREAM_ID = "irrelevant_stream_id";

    private Tuple mockNormalTuple(Object obj) {
        Tuple tuple = MockTupleHelpers.mockTuple(ANY_NON_SYSTEM_COMPONENT_ID, ANY_NON_SYSTEM_STREAM_ID);
        when(tuple.getValue(0)).thenReturn(obj);
        return tuple;
    }

    @SuppressWarnings("rawtypes")
    @Test
    public void shouldEmitNothingIfNoObjectHasBeenCountedYetAndTickTupleIsReceived() {
        // given
        Tuple tickTuple = MockTupleHelpers.mockTickTuple();
        RollingCountBolt bolt = new RollingCountBolt();
        Map conf = mock(Map.class);
        TopologyContext context = mock(TopologyContext.class);
        OutputCollector collector = mock(OutputCollector.class);
        bolt.prepare(conf, context, collector);

        // when
        bolt.execute(tickTuple);

        // then
        verifyZeroInteractions(collector);
    }

    @SuppressWarnings("rawtypes")
    @Test
    public void shouldEmitSomethingIfAtLeastOneObjectWasCountedAndTickTupleIsReceived() {
        // given
        Tuple normalTuple = mockNormalTuple(new Object());
        Tuple tickTuple = MockTupleHelpers.mockTickTuple();

        RollingCountBolt bolt = new RollingCountBolt();
        Map conf = mock(Map.class);
        TopologyContext context = mock(TopologyContext.class);
        OutputCollector collector = mock(OutputCollector.class);
        bolt.prepare(conf, context, collector);

        // when
        bolt.execute(normalTuple);
        bolt.execute(tickTuple);

        // then
        verify(collector).emit(any(Values.class));
    }

    @Test
    public void shouldDeclareOutputFields() {
        // given
        OutputFieldsDeclarer declarer = mock(OutputFieldsDeclarer.class);
        RollingCountBolt bolt = new RollingCountBolt();

        // when
        bolt.declareOutputFields(declarer);

        // then
        verify(declarer, times(1)).declare(any(Fields.class));

    }

    @Test
    public void shouldSetTickTupleFrequencyInComponentConfigurationToNonZeroValue() {
        // given
        RollingCountBolt bolt = new RollingCountBolt();

        // when
        Map<String, Object> componentConfig = bolt.getComponentConfiguration();

        // then
        assertThat(componentConfig).containsKey(Config.TOPOLOGY_TICK_TUPLE_FREQ_SECS);
        Integer emitFrequencyInSeconds = (Integer) componentConfig.get(Config.TOPOLOGY_TICK_TUPLE_FREQ_SECS);
        assertThat(emitFrequencyInSeconds).isGreaterThan(0);
    }
}