Added tests for HystrixStream

spring-cloud-netflix-hystrix-stream/src/main/java/org/springframework/cloud/netflix/hystrix/stream/HystrixStreamTask.java

@@ -67,7 +67,8 @@ public class HystrixStreamTask implements ApplicationContextAware {
 	@Autowired
 	private HystrixStreamProperties properties;
 
-	private final LinkedBlockingQueue<String> jsonMetrics = new LinkedBlockingQueue<>(
+	// Visible for testing
+	final LinkedBlockingQueue<String> jsonMetrics = new LinkedBlockingQueue<>(
 			1000);
 
 	private final JsonFactory jsonFactory = new JsonFactory();

spring-cloud-netflix-hystrix-stream/src/test/java/org/springframework/cloud/netflix/hystrix/stream/HystrixStreamTaskTests.java

+package org.springframework.cloud.netflix.hystrix.stream;
+
+import com.netflix.hystrix.HystrixCommandGroupKey;
+import com.netflix.hystrix.HystrixCommandKey;
+import com.netflix.hystrix.HystrixCommandMetrics;
+import com.netflix.hystrix.HystrixCommandProperties;
+import com.netflix.hystrix.strategy.properties.HystrixPropertiesCommandDefault;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.BDDMockito;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.Spy;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.context.ApplicationContext;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.then;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+/**
+ * @author Marcin Grzejszczak
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class HystrixStreamTaskTests {
+	@Mock MessageChannel outboundChannel;
+	@Mock DiscoveryClient discoveryClient;
+	@Mock ApplicationContext context;
+	@Spy HystrixStreamProperties properties;
+	@Mock ServiceInstance serviceInstance;
+	@InjectMocks HystrixStreamTask hystrixStreamTask;
+
+	@Test
+	public void should_not_send_metrics_when_they_are_empty() throws Exception {
+		this.hystrixStreamTask.sendMetrics();
+
+		verifyZeroInteractions(this.outboundChannel);
+	}
+
+	@Test
+	public void should_send_metrics_when_they_are_not_empty() throws Exception {
+		this.hystrixStreamTask.jsonMetrics.put("someJson");
+
+		this.hystrixStreamTask.sendMetrics();
+
+		then(this.outboundChannel).should().send(any(Message.class));
+	}
+
+	@Test
+	public void should_gather_json_metrics() throws Exception {
+		HystrixCommandKey hystrixCommandKey = HystrixCommandKey.Factory.asKey("commandKey");
+		HystrixCommandMetrics.getInstance(hystrixCommandKey,
+				HystrixCommandGroupKey.Factory.asKey("commandGroupKey"),
+				new HystrixPropertiesCommandDefault(hystrixCommandKey, HystrixCommandProperties.defaultSetter()));
+		given(this.discoveryClient.getLocalServiceInstance()).willReturn(this.serviceInstance);
+
+		this.hystrixStreamTask.gatherMetrics();
+
+		assertThat(this.hystrixStreamTask.jsonMetrics.isEmpty(), is(false));
+	}
+}
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