How to insert the request body?

Question

Help, guys, I have been assigned to research gatling with javascript for performance testing, but I am quite junior and struggling to even make a login request from a project.

This is the documentation: https://docs.gatling.io/reference/script/protocols/http/request/#request-name
There is also a nice video by a guy here, that I used for a double check, if I missed some prerequisite: https://www.youtube.com/watch?v=s4WeRrCAk-8

So far this is the solution I am coming up with:

import { atOnceUsers, scenario, simulation } from "@gatling.io/core";
import { http, status, StringBody } from "@gatling.io/http";
export default simulation((setUp) => {
 const httpProtocol = 
 http.baseUrl('https://example.test.com')
 .acceptHeader('*/*')
 .contentTypeHeader('application/json');
 const loginAndLogout = scenario('Login and logout')
 .exec(http('Login').post('/login')
 .body(StringBody("{ \"username\": \"testUser\", \"password\": \"testPass\", \"channel\": \"web\" }"))
 .check(status().is(200)) // Check for a 200 OK response
);
 setUp(loginAndLogout.injectOpen(atOnceUsers(1))).protocols(httpProtocol);
});

A simple get request is working, but a post request with a body is just not doing the job for me. I just get:

"[ERROR] i.g.a.Gatling$ - Run crashed org.graalvm.polyglot.PolyglotException: TypeError: undefined is not a function."

The error itself does not speak too much to me.

I have done previously a full project with "k6", but I am clueless here. Thanks.

• Jaromanda X: The error itself does not speak too much to me. - how do you think we feel? we can't even tell what part of your code threw the error!

Answer 1

The error lies in the imports:

import { atOnceUsers, scenario, simulation } from "@gatling.io/core";
import { http, status, StringBody } from "@gatling.io/http";

StringBody needs to be imported from core, not http:

import { StringBody, atOnceUsers, scenario, simulation } from "@gatling.io/core";
import { http, status } from "@gatling.io/http";

• JohnRambow99: Thank you very much, I feel kind of silly now. But sometimes I guess we need a second set of eyes even for obvious things. The request has passed. Anyway, I guess this may serve as an example of a POST request to someone else checking the internet :)