Gatling-Demo/src/test/java/com/demo/simulations/WebSocketEchoSimulation.java

package com.demo.simulations;

import static io.gatling.javaapi.core.CoreDsl.*;
import static io.gatling.javaapi.http.HttpDsl.*;

import io.gatling.javaapi.core.*;
import io.gatling.javaapi.http.*;

public class WebSocketEchoSimulation extends Simulation {

    HttpProtocolBuilder httpProtocol = http
            .baseUrl("https://socketsbay.com"); // Required by Gatling even if unused

    ScenarioBuilder scn = scenario("WebSocket Echo Test")
            .exec(
                    ws("Connect to Echo WS")
                            .connect("wss://socketsbay.com/wss/v2/1/demo/")
            )
            .pause(1)
            .exec(
                    ws("Send Message")
                            .sendText("Hello WebSocket")
                            .await(10) // 👈 await is chained here
                            .on(
                                    ws.checkTextMessage("Check Echo")
                                            .check(regex(".*Hello WebSocket.*"))
                            )
            )
            .pause(1)
            .exec(
                    ws("Close Connection")
                            .close()
            );

    {
        setUp(
                scn.injectOpen(atOnceUsers(1))
        ).protocols(httpProtocol);
    }
}