Add tests for ContainerLifecycleMicrometerHolder

Signed-off-by: Vineeth <vineeth>

Author: Vineeth

spring-kafka/src/test/java/org/springframework/kafka/support/micrometer/ContainerLifecycleMicrometerHolderTests.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2024-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.springframework.kafka.support.micrometer;
+
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ContainerLifecycleMicrometerHolder}.
+ *
+ * @author Vineeth Yelagandula
+ * @since 4.1.0
+ */
+public class ContainerLifecycleMicrometerHolderTests {
+
+	@Test
+	void startCounterIncrementsOnRecordStart() {
+		MeterRegistry registry = new SimpleMeterRegistry();
+		ContainerLifecycleMicrometerHolder holder =
+				new ContainerLifecycleMicrometerHolder(registry, "testContainer");
+
+		holder.recordStart();
+		holder.recordStart();
+
+		Counter startCounter = registry.find("spring.kafka.container.start.count")
+				.tag("name", "testContainer")
+				.counter();
+		assertThat(startCounter).isNotNull();
+		assertThat(startCounter.count()).isEqualTo(2.0);
+	}
+
+	@Test
+	void stopCounterIncrementsOnRecordStop() {
+		MeterRegistry registry = new SimpleMeterRegistry();
+		ContainerLifecycleMicrometerHolder holder =
+				new ContainerLifecycleMicrometerHolder(registry, "testContainer");
+
+		holder.recordStop();
+		holder.recordStop();
+		holder.recordStop();
+
+		Counter stopCounter = registry.find("spring.kafka.container.stop.count")
+				.tag("name", "testContainer")
+				.counter();
+		assertThat(stopCounter).isNotNull();
+		assertThat(stopCounter.count()).isEqualTo(3.0);
+	}
+
+	@Test
+	void countersAreTaggedWithContainerName() {
+		MeterRegistry registry = new SimpleMeterRegistry();
+		ContainerLifecycleMicrometerHolder holder =
+				new ContainerLifecycleMicrometerHolder(registry, "myContainer");
+
+		holder.recordStart();
+		holder.recordStop();
+
+		assertThat(registry.find("spring.kafka.container.start.count")
+				.tag("name", "myContainer").counter()).isNotNull();
+		assertThat(registry.find("spring.kafka.container.stop.count")
+				.tag("name", "myContainer").counter()).isNotNull();
+	}
+
+	@Test
+	void startAndStopCountersAreIndependent() {
+		MeterRegistry registry = new SimpleMeterRegistry();
+		ContainerLifecycleMicrometerHolder holder =
+				new ContainerLifecycleMicrometerHolder(registry, "testContainer");
+
+		holder.recordStart();
+		holder.recordStop();
+		holder.recordStop();
+
+		Counter startCounter = registry.find("spring.kafka.container.start.count")
+				.tag("name", "testContainer").counter();
+		Counter stopCounter = registry.find("spring.kafka.container.stop.count")
+				.tag("name", "testContainer").counter();
+
+		assertThat(startCounter).isNotNull();
+		assertThat(stopCounter).isNotNull();
+		assertThat(startCounter.count()).isEqualTo(1.0);
+		assertThat(stopCounter.count()).isEqualTo(2.0);
+	}
+
+}