add some hystrix tests, specifically check there is no discovery health indicator if it is not turned on

fixes gh-112

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/hystrix/HystrixOnlyTests.java

@@ -0,0 +1,115 @@
+package org.springframework.cloud.netflix.hystrix;
+
+import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.IntegrationTest;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.boot.test.TestRestTemplate;
+import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Spencer Gibb
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringApplicationConfiguration(classes = HystrixOnlyApplication.class)
+@WebAppConfiguration
+@IntegrationTest({ "server.port: 0" })
+@DirtiesContext
+public class HystrixOnlyTests {
+
+	@Value("${local.server.port}")
+	private int port;
+
+	@Test
+	public void testNormalExecution() {
+		String s = new TestRestTemplate().getForObject("http://localhost:" + port + "/", String.class);
+		assertEquals("incorrect response", "Hello world", s);
+	}
+
+	@Test
+	public void testFailureFallback() {
+		String s = new TestRestTemplate().getForObject("http://localhost:" + port + "/fail", String.class);
+		assertEquals("incorrect fallback", "Fallback Hello world", s);
+	}
+
+	@Test
+	public void testHystrixHealth() {
+		Map map = getHealth();
+		assertTrue("Missing hystrix health key", map.containsKey("hystrix"));
+		Map hystrix = (Map) map.get("hystrix");
+		assertEquals("Wrong hystrix status", "UP", hystrix.get("status"));
+	}
+
+	@Test
+	public void testNoDiscoveryHealth() {
+		Map map = getHealth();
+		//There is explicitly no discovery, so there should be no discovery health key
+		assertFalse("Incorrect existing discovery health key", map.containsKey("discovery"));
+	}
+
+	private Map getHealth() {
+		return new TestRestTemplate().getForObject("http://localhost:" + port + "/admin/health", Map.class);
+	}
+}
+
+class Service {
+	@HystrixCommand
+	public String hello() {
+		return "Hello world";
+	}
+
+	@HystrixCommand(fallbackMethod = "fallback")
+	public String fail() {
+		throw new RuntimeException("Always fail");
+	}
+
+	public String fallback() {
+		return "Fallback Hello world";
+	}
+}
+
+//Don't use @SpringBootApplication because we don't want to component scan
+@Configuration
+@EnableAutoConfiguration
+@EnableCircuitBreaker
+@RestController
+class HystrixOnlyApplication {
+
+	@Bean
+	public Service service() {
+		return new Service();
+	}
+
+	@Autowired
+	Service service;
+
+	@RequestMapping("/")
+	public String home() {
+		return service.hello();
+	}
+
+	@RequestMapping("/fail")
+	public String fail() {
+		return service.fail();
+	}
+
+	public static void main(String[] args) {
+		SpringApplication.run(HystrixOnlyApplication.class, args);
+	}
+}