Polish "Add auto-configuration for RabbitMQ metrics"

Closes gh-10887

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/amqp/RabbitMetricsTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012-2018 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
+ *
+ *      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.springframework.boot.actuate.metrics.amqp;
+
+import com.rabbitmq.client.ConnectionFactory;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link RabbitMetrics}.
+ *
+ * @author Stephane Nicoll
+ */
+public class RabbitMetricsTests {
+
+	@Test
+	public void connectionFactoryIsInstrumented() {
+		ConnectionFactory connectionFactory = mockConnectionFactory();
+		SimpleMeterRegistry registry = new SimpleMeterRegistry();
+		new RabbitMetrics(connectionFactory, "rabbit", null).bindTo(registry);
+		assertThat(registry.find("rabbit.connections").meter()).isPresent();
+	}
+
+	@Test
+	public void connectionFactoryWithTagsIsInstrumented() {
+		ConnectionFactory connectionFactory = mockConnectionFactory();
+		SimpleMeterRegistry registry = new SimpleMeterRegistry();
+		new RabbitMetrics(connectionFactory, "test", Tags.zip("env", "prod"))
+				.bindTo(registry);
+		assertThat(registry.find("test.connections")
+				.tags("env", "prod").meter()).isPresent();
+		assertThat(registry.find("test.connections")
+				.tags("env", "dev").meter()).isNotPresent();
+	}
+
+	private ConnectionFactory mockConnectionFactory() {
+		return mock(ConnectionFactory.class);
+	}
+
+}