WebSocket is a powerful communication protocol that allows bidirectional communication between a client and a server over a single TCP connection. Testing WebSocket endpoints is crucial to ensure the smooth functioning of real-time applications. In this blog post, we will explore how to write Arquillian tests for WebSocket endpoints.

What is Arquillian?

Arquillian is a powerful testing framework that simplifies the testing process for Java-based applications. It provides a container-driven approach, allowing you to run tests inside a real container, such as JBoss, WildFly, or Tomcat, to simulate a real-world environment. Arquillian integrates seamlessly with popular testing frameworks like JUnit and TestNG.

Setting Up the Environment

Before diving into writing Arquillian tests for WebSocket endpoints, we need to set up the testing environment. Start by adding the necessary dependencies to your Maven or Gradle project.

For Maven, include the following dependencies in your pom.xml file:

<dependencies>
  <dependency>
    <groupId>org.jboss.arquillian.container</groupId>
    <artifactId>arquillian-junit-container</artifactId>
    <scope>test</scope>
  </dependency>
  <!-- Add additional dependencies based on your container choice, e.g., arquillian-tomcat-embedded -->
</dependencies>

For Gradle, add the following dependencies to your build.gradle file:

testImplementation 'org.jboss.arquillian.junit:arquillian-junit-container:1.5.0.Final'
// Add additional dependencies based on your container choice, e.g., arquillian-tomcat-embedded

Next, create a test class and annotate it with @RunWith(Arquillian.class) to tell JUnit to use Arquillian for running the tests.

@RunWith(Arquillian.class)
public class WebSocketEndpointTest {

}

Writing WebSocket Endpoint Tests

To write tests for WebSocket endpoints, we need to deploy the endpoint to a container and interact with it using a WebSocket client. Arquillian provides a built-in WebSocketClient extension that simplifies this process.

Let’s assume we have a WebSocket endpoint called MyWebSocketEndpoint that echoes back any message it receives.

@ServerEndpoint("/websocket")
public class MyWebSocketEndpoint {

  @OnMessage
  public void onMessage(String message, Session session) throws IOException {
    session.getBasicRemote().sendText(message);
  }
}

To test this endpoint using Arquillian, we can define a test method that connects to the endpoint using the WebSocketClient and sends a message.

@Test
public void testWebSocketEndpoint(@ArquillianResource URL baseURL) throws Exception {
  URI uri = new URI(baseURL.toString().replace("http", "ws") + "/websocket");
  WebSocketContainer container = ContainerProvider.getWebSocketContainer();
  Session session = container.connectToServer(new Endpoint() {
    @Override
    public void onOpen(Session session, EndpointConfig config) {
      // Perform necessary setup
    }
  }, uri);

  session.getBasicRemote().sendText("Hello, Arquillian!");

  String response = "";  
  while (response.isEmpty()) {
    response = session.getBasicRemote().receiveText();
    Thread.sleep(200);
  }
  
  assertEquals("Hello, Arquillian!", response);
}

In the above example, we convert the base URL to a WebSocket URL, create a WebSocket container, and connect to the server using the WebSocket endpoint. We then send a message to the server and wait for a response. Finally, we assert that the received message matches the sent message.

Conclusion

Writing Arquillian tests for WebSocket endpoints allows us to ensure the correct functioning of our WebSocket-based applications. By leveraging Arquillian’s container-driven testing approach and the built-in WebSocket support, we can test WebSocket endpoints in a real-world environment.

#WebSocket #Arquillian