Search code examples
spring-bootspring-mvcjunit5spring-websocketspring-boot-test

Unit Test For Websocket Returns Null


I am trying to implement unit test for a Websocket in Springboot with JUnit.

I am following this link and it runs fine but gets null in the result, when i test my websocket with a browser it sends the desire results.

let me show my test class

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes =Main.class)
@WebAppConfiguration
public class WebSocketTest {

static final String WEBSOCKET_URI = "http://localhost:8080/api/realtimedata";
static final String WEBSOCKET_TOPIC = "/realtimedata";

BlockingQueue<WebSocketData> blockingQueue;
WebSocketStompClient stompClient;

@BeforeEach
public void setup() {

    blockingQueue = new LinkedBlockingDeque<>();
    stompClient = new WebSocketStompClient(new SockJsClient(
            asList(new WebSocketTransport(new StandardWebSocketClient()))));
}

@Test
public void shouldReceiveAMessageFromTheServer() throws Exception {
    StompSession session = stompClient
            .connect(WEBSOCKET_URI, new StompSessionHandlerAdapter() {})
            .get(1, SECONDS);
    session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());

    String message = "{\"groupId\":\"grp-1\", \"accountId\":\"acc-1\", \"userId\":\"usr-1\"}";
    session.send(WEBSOCKET_TOPIC, message.getBytes()); 
    Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, SECONDS));
}

class DefaultStompFrameHandler implements StompFrameHandler {
    @Override
    public Type getPayloadType(StompHeaders stompHeaders) {
        return WebSocketData.class;
    }

    @Override
    public void handleFrame(StompHeaders stompHeaders, Object o) {
        blockingQueue.offer((WebSocketData) o);
    }
}

}

Here is my WebSocketConfiguration class

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfiguration implements WebSocketMessageBrokerConfigurer {

@Override
public void configureMessageBroker(MessageBrokerRegistry registry) {
    registry.enableSimpleBroker("/realtimedata");
    registry.setApplicationDestinationPrefixes("/wsconn");
}

@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
    registry.addEndpoint("/realtimedata")
            .setAllowedOrigins("*")
            .withSockJS();
}

}

This is response I get from server

org.opentest4j.AssertionFailedError: 
Expected :trying to figureout
Actual   :null

Update:

After adding the changes recommended by Rieckpil in answer below and with some further research my test class looks like this now

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class ServerWebSocketTest {

@LocalServerPort
private Integer port;

static final String WEBSOCKET_TOPIC = "/realtimedata";

BlockingQueue<WebSocketData> blockingQueue;
WebSocketStompClient stompClient;

@BeforeEach
public void setup() {

    blockingQueue = new LinkedBlockingDeque<>();
    stompClient = new WebSocketStompClient(new SockJsClient(
            asList(new WebSocketTransport(new StandardWebSocketClient()))));

    // might be required
    stompClient.setMessageConverter(new MappingJackson2MessageConverter());

}

@Test
public void shouldReceiveAMessageFromTheServer() throws Exception {
    StompSession session = stompClient
            .connect(getWsPath(), **new DefaultStompFrameHandler()** {
            })
            .get(1, TimeUnit.SECONDS);
    session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());

    String message = "{\"groupId\":\"grp-1\", \"accountId\":\"acc-1\", \"userId\":\"usr-1\"}";
    session.send(WEBSOCKET_TOPIC, message.getBytes());
    Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, TimeUnit.SECONDS));
}

class DefaultStompFrameHandler **extends StompSessionHandlerAdapter**{   
    @Override
    public Type getPayloadType(StompHeaders stompHeaders) {
        return WebSocketData.class;
    }

    @Override
    public void handleFrame(StompHeaders stompHeaders, Object o) {
        blockingQueue.offer((WebSocketData) o);
    }

    **@Override
    public void handleException(StompSession session, StompCommand command, StompHeaders headers, byte[] payload, Throwable exception) {
        exception.printStackTrace();
    }**
}
private String getWsPath() {
    return String.format("ws://localhost:%d/location_services/realtimedata", port);
}

}

After these changes I am now able to get the stacktraces to print in logs

here is the exception that I got after these changes

 org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
 at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
 at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1], failedMessage=GenericMessage [payload=byte[82], headers={simpMessageType=MESSAGE, stompCommand=MESSAGE, nativeHeaders={destination=[/realtimedata], content-type=[application/json], subscription=[0], message-id=[cc55448f0b4f447d8f6bc7662acd15db-0], content-length=[82]}, simpSubscriptionId=0, contentType=application/json, simpSessionId=2df73ca0-e13b-c479-4591-37e9f7e8d689, simpDestination=/realtimedata}]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:235)
    at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:197)
    at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:188)
    at org.springframework.messaging.simp.stomp.DefaultStompSession.invokeHandler(DefaultStompSession.java:477)
    at org.springframework.messaging.simp.stomp.DefaultStompSession.handleMessage(DefaultStompSession.java:429)
    at org.springframework.web.socket.messaging.WebSocketStompClient$WebSocketTcpConnectionHandlerAdapter.handleMessage(WebSocketStompClient.java:340)
    at org.springframework.web.socket.handler.WebSocketHandlerDecorator.handleMessage(WebSocketHandlerDecorator.java:75)
    at org.springframework.web.socket.handler.LoggingWebSocketHandlerDecorator.handleMessage(LoggingWebSocketHandlerDecorator.java:56)
    at org.springframework.web.socket.sockjs.client.AbstractClientSockJsSession.handleMessageFrame(AbstractClientSockJsSession.java:294)
    at org.springframework.web.socket.sockjs.client.AbstractClientSockJsSession.handleFrame(AbstractClientSockJsSession.java:230)
    at org.springframework.web.socket.sockjs.client.WebSocketTransport$ClientSockJsWebSocketHandler.handleTextMessage(WebSocketTransport.java:163)
    at org.springframework.web.socket.handler.AbstractWebSocketHandler.handleMessage(AbstractWebSocketHandler.java:43)
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.handleTextMessage(StandardWebSocketHandlerAdapter.java:114)
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.access$000(StandardWebSocketHandlerAdapter.java:43)
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:85)
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:82)
    at org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:395)
    at org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:495)
    at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:294)
    at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:133)
    at org.apache.tomcat.websocket.WsFrameClient.processSocketRead(WsFrameClient.java:95)
    at org.apache.tomcat.websocket.WsFrameClient.resumeProcessing(WsFrameClient.java:209)
    at org.apache.tomcat.websocket.WsFrameClient.access$300(WsFrameClient.java:31)
    at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.doResumeProcessing(WsFrameClient.java:186)
    at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.completed(WsFrameClient.java:163)
    at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.completed(WsFrameClient.java:148)
    at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:127)
    at java.base/sun.nio.ch.Invoker$2.run(Invoker.java:219)
    at java.base/sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
 at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1432)
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1062)
    at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371)
    at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1373)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4218)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3309)
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:219)
    ... 31 more
            

org.opentest4j.AssertionFailedError: 
Expected :trying to figureout
Actual   :null
 

Can anyone please guid me what am I doing wrong?

Thanks.


Solution

  • You should configure your integration test to use the started Spring context and don't hardcode 8080.

    Furthermore, ensure you have a MessageConverter configured for your WebSocketStompClient that fits your use case. The default is SimpleMessageConverter. As you are sending byte[], the ByteArrayMessageConverter should fit.

    Your test can be refactored to the following:

    @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
    public class Test {
    
      @LocalServerPort
      private Integer port;
      
      static final String WEBSOCKET_TOPIC = "/realtimedata";
    
      BlockingQueue<WebSocketData> blockingQueue;
      WebSocketStompClient stompClient;
    
      @BeforeEach
      public void setup() {
    
        blockingQueue = new LinkedBlockingDeque<>();
        stompClient = new WebSocketStompClient(new SockJsClient(
          asList(new WebSocketTransport(new StandardWebSocketClient()))));
    
        webSocketStompClient.setMessageConverter(new ByteArrayMessageConverter()); 
    
      }
    
      @Test
      public void shouldReceiveAMessageFromTheServer() throws Exception {
        StompSession session = stompClient
          .connect(getWsPath(), new StompSessionHandlerAdapter() {
          })
          .get(1, SECONDS);
        session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());
    
        String message = "{\"groupId\":\"grp-1\", \"accountId\":\"acc-1\", \"userId\":\"usr-1\"}";
        session.send(WEBSOCKET_TOPIC, message.getBytes());
        Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, SECONDS));
      }
    
      class DefaultStompFrameHandler implements StompFrameHandler {
        @Override
        public Type getPayloadType(StompHeaders stompHeaders) {
          return WebSocketData.class;
        }
    
        @Override
        public void handleFrame(StompHeaders stompHeaders, Object o) {
          blockingQueue.offer((WebSocketData) o);
        }
      }
      
      private String getWsPath() {
        return String.format("ws://localhost:%d/api/realtimedata", port);
      }
    
    }
    

    This test will start the whole Spring context, the embedded servlet container on a random port, and try to connect to your endpoint.