Fix failing test

Issue: SPR-10800

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/handler/AbstractHttpReceivingTransportHandler.java

@@ -24,6 +24,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.server.ServerHttpRequest;
 import org.springframework.http.server.ServerHttpResponse;
+import org.springframework.util.Assert;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketHandler;
 import org.springframework.web.socket.WebSocketSession;
@@ -45,12 +46,13 @@ public abstract class AbstractHttpReceivingTransportHandler
 
 	@Override
 	public final void handleRequest(ServerHttpRequest request, ServerHttpResponse response,
-			WebSocketHandler webSocketHandler, WebSocketSession webSocketSession) throws SockJsProcessingException {
+			WebSocketHandler wsHandler, WebSocketSession wsSession) throws SockJsProcessingException {
 
 		// TODO: check "Sec-WebSocket-Protocol" header
 		// https://github.com/sockjs/sockjs-client/issues/130
 
-		handleRequestInternal(request, response, webSocketHandler, webSocketSession);
+		Assert.notNull(wsSession, "No session");
+		handleRequestInternal(request, response, wsHandler, wsSession);
 	}
 
 	protected void handleRequestInternal(ServerHttpRequest request, ServerHttpResponse response,

spring-websocket/src/test/java/org/springframework/web/socket/sockjs/transport/handler/HttpReceivingTransportHandlerTests.java

@@ -24,9 +24,6 @@ import org.springframework.web.socket.CloseStatus;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketHandler;
 import org.springframework.web.socket.sockjs.SockJsProcessingException;
-import org.springframework.web.socket.sockjs.transport.handler.AbstractHttpReceivingTransportHandler;
-import org.springframework.web.socket.sockjs.transport.handler.JsonpTransportHandler;
-import org.springframework.web.socket.sockjs.transport.handler.XhrTransportHandler;
 import org.springframework.web.socket.sockjs.transport.session.AbstractSockJsSession;
 import org.springframework.web.socket.sockjs.transport.session.StubSockJsServiceConfig;
 import org.springframework.web.socket.sockjs.transport.session.TestSockJsSession;
@@ -97,12 +94,10 @@ public class HttpReceivingTransportHandlerTests  extends AbstractHttpRequestTest
 		handleRequestAndExpectFailure();
 	}
 
-	@Test
+	@Test(expected=IllegalArgumentException.class)
 	public void readMessagesNoSession() throws Exception {
 		WebSocketHandler webSocketHandler = mock(WebSocketHandler.class);
 		new XhrTransportHandler().handleRequest(this.request, this.response, webSocketHandler, null);
-
-		assertEquals(404, this.servletResponse.getStatus());
 	}
 
 	@Test