Practice and Summary

package com.example;

import io.gatling.javaapi.core.*;
import io.gatling.javaapi.http.*;
import java.time.Duration;

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

public class ShoppingPortalSimulation extends Simulation {

    // Protocol
    HttpProtocolBuilder httpProtocol = http
        .baseUrl("https://www.testerrank.com")
        .acceptHeader("text/html,application/json")
        .userAgentHeader("Gatling/ShoppingTest");

    // Feeder
    FeederBuilder<String> userFeeder = csv("data/users.csv").random();

    // Reusable chains
    ChainBuilder login = feed(userFeeder)
        .exec(
            http("Login")
                .post("/api/login")
                .body(StringBody(
                    "{\"email\":\"#{email}\",\"password\":\"#{password}\"}"
                ))
                .asJson()
                .check(
                    status().is(200),
                    jsonPath("$.token").saveAs("authToken")
                )
        );

    ChainBuilder browse = exec(
        http("Product List")
            .get("/shopping")
            .check(status().is(200))
    ).pause(Duration.ofSeconds(1), Duration.ofSeconds(3))
    .exec(
        http("Product Detail")
            .get("/shopping/products/1")
            .check(status().is(200))
    );

    ChainBuilder addToCart = exec(
        http("Add to Cart")
            .post("/api/cart")
            .header("Authorization", "Bearer #{authToken}")
            .body(StringBody("{\"productId\":1,\"qty\":1}"))
            .asJson()
            .check(status().in(200, 201))
    );

    // Scenario
    ScenarioBuilder browseAndBuy = scenario("Browse and Buy")
        .exec(login)
        .pause(Duration.ofSeconds(2), Duration.ofSeconds(4))
        .exec(browse)
        .pause(Duration.ofSeconds(1), Duration.ofSeconds(2))
        .exec(addToCart);

    // setUp
    {
        setUp(
            browseAndBuy.injectOpen(
                rampUsers(50).during(Duration.ofSeconds(30)),
                constantUsersPerSec(5).during(Duration.ofMinutes(2))
            )
        ).protocols(httpProtocol)
         .assertions(
             global().responseTime().percentile(95.0).lt(3000),
             global().responseTime().percentile(99.0).lt(5000),
             global().successfulRequests().percent().gt(99.0)
         );
    }
}