test: RecordProcessor에서 연속인 경우에만 동작하는지 검증.

- 검증을 위해 ConsumerStats 에서 package-private Getter 추가

src/main/java/com/sangdol/consumer/infrastructure/kafka/consumer/ConsumerStats.java

@@ -4,6 +4,8 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 
+import com.google.common.annotations.VisibleForTesting;
+
 public class ConsumerStats {
 
 	private final int workerThreads;
@@ -27,4 +29,9 @@ public class ConsumerStats {
 			.collect(Collectors.averagingLong(Long::longValue))
 			.longValue();
 	}
+
+	@VisibleForTesting
+	Map<String, Long> getThreadElapsedTime() {
+		return threadElapsedTime;
+	}
 }

src/main/java/com/sangdol/consumer/infrastructure/kafka/consumer/RecordProcessor.java

@@ -22,7 +22,7 @@ public class RecordProcessor {
 	private long initialRecordReceivedTime = 0;
 
 	public void process(ConsumerRecords<String, TestRecord> records) throws Exception {
-		initializeTime();
+		preProcess();
 
 		log.debug("[RecordProcessor] process {} records. thread: {}", records.count(),
 			Thread.currentThread().getName());
@@ -50,9 +50,11 @@ public class RecordProcessor {
 		}
 	}
 
-	private void initializeTime() {
+	private void preProcess() {
 		if (initialRecordReceivedTime == 0) {
 			initialRecordReceivedTime = System.currentTimeMillis();
 		}
+
+		emptyPollResultCount.set(0);
 	}
 }

src/test/java/com/sangdol/consumer/infrastructure/kafka/consumer/RecordProcessorTest.java

@@ -0,0 +1,90 @@
+package com.sangdol.consumer.infrastructure.kafka.consumer;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.common.TopicPartition;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import com.sangdol.consumer.domain.TestRecord;
+import com.sangdol.consumer.infrastructure.kafka.producer.DLTProducer;
+
+class RecordProcessorTest {
+
+	private static final ConsumerRecords<String, TestRecord> RECORDS = new ConsumerRecords<>(Map.of(
+		new TopicPartition("test", 1),
+		List.of(new ConsumerRecord<>(
+			"test",
+			1,
+			2,
+			"key",
+			new TestRecord(123, "test", Instant.now().toString())
+		))
+	));
+
+	private static final ConsumerRecords<String, TestRecord> EMPTY = ConsumerRecords.empty();
+
+	@DisplayName("5회 연속으로 빈 레코드를 받으면 poll 작업의 완료로 판단한다.")
+	@Test
+	void receiveEmptyRecordsMoreThanOrEqualThreshold() {
+		// given
+		ConsumerStats consumerStats = new ConsumerStats(3);
+		RecordProcessor recordProcessor = new RecordProcessor(mock(DLTProducer.class), consumerStats);
+
+		// 시간 초기화를 위해 레코드를 담아 1회 전송
+		test(recordProcessor, RECORDS);
+
+		// when
+		for (int i = 0; i < 5; i++) {
+			test(recordProcessor, EMPTY);
+		}
+
+		Map<String, Long> result = consumerStats.getThreadElapsedTime();
+
+		assertThat(result).isNotEmpty();
+		assertThat(result.containsKey(Thread.currentThread().getName())).isTrue();
+	}
+
+	@DisplayName("5회 연속으로 빈 레코드를 받지 않으면 poll 작업의 완료로 판단하지 않는다.")
+	@Test
+	void receiveEmptyRecordsLessThanThreshold() {
+		// given
+		ConsumerStats consumerStats = new ConsumerStats(3);
+		RecordProcessor recordProcessor = new RecordProcessor(mock(DLTProducer.class), consumerStats);
+
+		// 시간 초기화를 위해 레코드를 담아 1회 전송
+		test(recordProcessor, RECORDS);
+
+		// when
+		// 3회 빈 레코드 -> 이후 비어있지 않은 레코드 -> 빈 레코드
+		for (int i = 0; i < 3; i++) {
+			test(recordProcessor, EMPTY);
+		}
+		test(recordProcessor, RECORDS);
+		test(recordProcessor, EMPTY);
+
+		// then
+		Map<String, Long> result = consumerStats.getThreadElapsedTime();
+
+		assertThat(result).isEmpty();
+	}
+
+	private void test(RecordProcessor recordProcessor, ConsumerRecords<String, TestRecord> records) {
+		if (records.isEmpty()) {
+			recordProcessor.processIfEmptyRecords();
+			return;
+		}
+		try {
+			recordProcessor.process(records);
+		} catch (Exception e) {
+			throw new RuntimeException(e);
+		}
+	}
+}