[JAVA-10431] Use Wiremock to fix intermittent test failures

spring-cloud/pom.xml

@@ -46,7 +46,7 @@
         <module>spring-cloud-circuit-breaker</module>
         <module>spring-cloud-eureka-self-preservation</module>
         <!-- <module>spring-cloud-openfeign</module> --> <!-- Fixing under JAVA-10446 -->
-        <!-- <module>spring-cloud-netflix-feign</module>  --> <!-- Fixing under JAVA-10431 -->
+        <module>spring-cloud-netflix-feign</module>
         <module>spring-cloud-sentinel</module>
         <module>spring-cloud-dapr</module>
         <module>spring-cloud-docker</module>

spring-cloud/spring-cloud-netflix-feign/pom.xml

@@ -51,13 +51,16 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-contract-wiremock</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <properties>
         <spring-cloud.version>Camden.SR7</spring-cloud.version>
         <feign-ok.version>8.18.0</feign-ok.version>
-        <!-- <spring-cloud.version>Hoxton.SR8</spring-cloud.version> -->
-        <!-- <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> -->
     </properties>
 
 </project>

spring-cloud/spring-cloud-netflix-feign/src/main/java/com/baeldung/cloud/netflix/feign/client/JSONPlaceHolderClient.java

@@ -11,15 +11,15 @@
 import java.util.List;
 
 @FeignClient(value = "jplaceholder",
-        url = "https://jsonplaceholder.typicode.com/",
+        url = "${external.api.url}",
         configuration = ClientConfiguration.class,
         fallback = JSONPlaceHolderFallback.class)
 public interface JSONPlaceHolderClient {
 
     @RequestMapping(method = RequestMethod.GET, value = "/posts")
     List<Post> getPosts();
 
-
     @RequestMapping(method = RequestMethod.GET, value = "/posts/{postId}", produces = "application/json")
     Post getPostById(@PathVariable("postId") Long postId);
+
 }

spring-cloud/spring-cloud-netflix-feign/src/main/resources/application.properties

@@ -1,3 +1,5 @@
 spring.application.name=netflix-feign
 logging.level.com.baeldung.cloud.netflix.feign.client=DEBUG
 feign.hystrix.enabled=true
+
+external.api.url=https://jsonplaceholder.typicode.com/

spring-cloud/spring-cloud-netflix-feign/src/test/java/com/baeldung/cloud/netflix/feign/NetflixFeignUnitTest.java

@@ -2,42 +2,97 @@
 
 import com.baeldung.cloud.netflix.feign.model.Post;
 import com.baeldung.cloud.netflix.feign.service.JSONPlaceHolderService;
+import com.github.tomakehurst.wiremock.client.ResponseDefinitionBuilder;
+import com.github.tomakehurst.wiremock.client.WireMock;
+import com.github.tomakehurst.wiremock.verification.LoggedRequest;
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.contract.wiremock.AutoConfigureWireMock;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.test.context.junit4.SpringRunner;
 
 import java.util.List;
 
-import static org.junit.Assert.assertFalse;
+import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
+import static com.github.tomakehurst.wiremock.client.WireMock.exactly;
+import static com.github.tomakehurst.wiremock.client.WireMock.get;
+import static com.github.tomakehurst.wiremock.client.WireMock.getRequestedFor;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static com.github.tomakehurst.wiremock.client.WireMock.verify;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 @RunWith(SpringRunner.class)
-@SpringBootTest
+@SpringBootTest(properties = {"external.api.url=http://localhost:${wiremock.server.port}"})
+@AutoConfigureWireMock(port = 0)
 public class NetflixFeignUnitTest {
 
     @Autowired
     private JSONPlaceHolderService jsonPlaceHolderService;
 
+    @Before
+    public void setup() {
+        WireMock.reset();
+    }
+
     @Test
-    public void whenSpringContextIsBootstrapped_thenNoExceptions() {
+    public void givenExternalApiAvailable_whenGetPosts_thenPostsReturned() {
+
+        WireMock.stubFor(get(urlEqualTo("/posts"))
+          .willReturn(okJson("[{ \"userId\": 1, \"id\": 1, \"title\": \"post 1 title\", \"body\": \"post 1 body\" }, "
+              + "{ \"userId\": 1, \"id\": 2, \"title\": \"post 2 title\", \"body\": \"post 2 body\" }]")));
+
+        List<Post> posts = jsonPlaceHolderService.getPosts();
+
+        assertEquals(2, posts.size());
+        verify(exactly(1), getRequestedFor(urlEqualTo("/posts")));
     }
 
     @Test
-    public void whenGetPosts_thenListPostSizeGreaterThanZero() {
+    public void givenExternalApiUnavailable_whenGetPosts_thenEmpty() {
+
+        WireMock.stubFor(get(urlEqualTo("/posts"))
+          .willReturn(aResponse().withStatus(500)));
 
         List<Post> posts = jsonPlaceHolderService.getPosts();
 
-        assertFalse(posts.isEmpty());
+        assertTrue(posts.isEmpty());
+        verify(exactly(1), getRequestedFor(urlEqualTo("/posts")));
     }
 
     @Test
-    public void whenGetPostWithId_thenPostExist() {
+    public void givenExternalApiAvailable_whenGetPostWithId_thenPostExists() {
+
+        WireMock.stubFor(get(urlEqualTo("/posts/1"))
+          .willReturn(okJson("{ \"userId\": 1, \"id\": 1, \"title\": \"post 1 title\", \"body\": \"post 1 body\" }")));
 
         Post post = jsonPlaceHolderService.getPostById(1L);
 
         assertNotNull(post);
+        verify(exactly(1), getRequestedFor(urlEqualTo("/posts/1")));
     }
 
+    @Test
+    public void givenExternalApiUnavailable_whenGetPostWithId_thenNull() {
+
+        WireMock.stubFor(get(urlEqualTo("/posts/1"))
+          .willReturn(aResponse().withStatus(500)));
+
+        Post post = jsonPlaceHolderService.getPostById(1L);
+
+        assertNull(post);
+        verify(exactly(1), getRequestedFor(urlEqualTo("/posts/1")));
+    }
+
+    private static ResponseDefinitionBuilder okJson(String json) {
+        return aResponse()
+          .withHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+          .withBody(json);
+    }
 }