docs: update microservices idempotent consumer

microservices-idempotent-consumer/src/main/java/com/iluwatar/idempotentconsumer/RequestService.java

@@ -44,7 +44,7 @@ public class RequestService {
   }
 
   /**
-   * Creates a new Request or returns an existing one by it's UUID. This operation is idempotent:
+   * Creates a new Request or returns an existing one by its UUID. This operation is idempotent:
    * performing it once or several times successively leads to an equivalent result.
    *
    * @param uuid The unique identifier for the Request.
@@ -52,10 +52,7 @@ public class RequestService {
    */
   public Request create(UUID uuid) {
     Optional<Request> optReq = requestRepository.findById(uuid);
-    if (!optReq.isEmpty()) {
-      return optReq.get();
-    }
-    return requestRepository.save(new Request(uuid));
+    return optReq.orElseGet(() -> requestRepository.save(new Request(uuid)));
   }
 
   /**

microservices-idempotent-consumer/src/test/java/com/iluwatar/idempotentconsumer/AppTest.java

@@ -39,12 +39,12 @@ import org.springframework.boot.CommandLineRunner;
 class AppTest {
 
   @Test
-  void main() {
+  void testMain() {
     assertDoesNotThrow(() -> App.main(new String[] {}));
   }
 
   @Test
-  void run() throws Exception {
+  void testRun() throws Exception {
     RequestService requestService = Mockito.mock(RequestService.class);
     RequestRepository requestRepository = Mockito.mock(RequestRepository.class);
     UUID uuid = UUID.randomUUID();

microservices-idempotent-consumer/src/test/java/com/iluwatar/idempotentconsumer/RequestServiceTests.java

@@ -43,11 +43,10 @@ import org.mockito.junit.jupiter.MockitoExtension;
 class RequestServiceTests {
   private RequestService requestService;
   @Mock private RequestRepository requestRepository;
-  private RequestStateMachine requestStateMachine;
 
   @BeforeEach
   void setUp() {
-    requestStateMachine = new RequestStateMachine();
+    RequestStateMachine requestStateMachine = new RequestStateMachine();
     requestService = new RequestService(requestRepository, requestStateMachine);
   }
 

microservices-idempotent-consumer/src/test/java/com/iluwatar/idempotentconsumer/RequestStateMachineTests.java

@@ -35,7 +35,7 @@ class RequestStateMachineTests {
   private RequestStateMachine requestStateMachine;
 
   @BeforeEach
-  public void setUp() {
+  void setUp() {
     requestStateMachine = new RequestStateMachine();
   }