Re-enable Reactor WebSocket integration tests

spring-web-reactive/src/test/java/org/springframework/web/reactive/socket/server/AbstractWebSocketIntegrationTests.java

@@ -33,8 +33,8 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.bootstrap.HttpServer;
-import org.springframework.http.server.reactive.bootstrap.ReactorHttpServer;
 import org.springframework.http.server.reactive.bootstrap.JettyHttpServer;
+import org.springframework.http.server.reactive.bootstrap.ReactorHttpServer;
 import org.springframework.http.server.reactive.bootstrap.RxNettyHttpServer;
 import org.springframework.http.server.reactive.bootstrap.TomcatHttpServer;
 import org.springframework.http.server.reactive.bootstrap.UndertowHttpServer;
@@ -42,8 +42,8 @@ import org.springframework.util.SocketUtils;
 import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.socket.server.support.HandshakeWebSocketService;
 import org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter;
-import org.springframework.web.reactive.socket.server.upgrade.ReactorNettyRequestUpgradeStrategy;
 import org.springframework.web.reactive.socket.server.upgrade.JettyRequestUpgradeStrategy;
+import org.springframework.web.reactive.socket.server.upgrade.ReactorNettyRequestUpgradeStrategy;
 import org.springframework.web.reactive.socket.server.upgrade.RxNettyRequestUpgradeStrategy;
 import org.springframework.web.reactive.socket.server.upgrade.TomcatRequestUpgradeStrategy;
 import org.springframework.web.reactive.socket.server.upgrade.UndertowRequestUpgradeStrategy;
@@ -72,7 +72,7 @@ public abstract class AbstractWebSocketIntegrationTests {
 	public static Object[][] arguments() {
 		File base = new File(System.getProperty("java.io.tmpdir"));
 		return new Object[][] {
-				//{new ReactorHttpServer(), ReactorNettyConfig.class},
+				{new ReactorHttpServer(), ReactorNettyConfig.class},
 				{new RxNettyHttpServer(), RxNettyConfig.class},
 				{new TomcatHttpServer(base.getAbsolutePath(), WsContextListener.class), TomcatConfig.class},
 				{new UndertowHttpServer(), UndertowConfig.class},

spring-web-reactive/src/test/java/org/springframework/web/reactive/socket/server/WebSocketIntegrationTests.java

@@ -149,7 +149,8 @@ public class WebSocketIntegrationTests extends AbstractWebSocketIntegrationTests
 
 		@Override
 		public Mono<Void> handle(WebSocketSession session) {
-			return session.send(session.receive());
+			// Use retain() for Reactor Netty
+			return session.send(session.receive().doOnNext(WebSocketMessage::retain));
 		}
 	}