"undefined is not a function" error when feeding my simulation with .json/.csv file

Hanna · December 23, 2024, 8:08pm

Gatling version: 3.13.2
Gatling flavor: javascript
Gatling build tool: maven gradle sbt bundle npm

My simulation works perfectly when retrieves only one key-value pair from .json/.csv file. But once I want to retrieve random value from .json/.csv file and add feeder - I receive error “undefined is not a function”.
My simulation with csv feeding:

import {
    simulation,
    scenario,
    pause,
    atOnceUsers,
    AllowList,
    DenyList,
    StringBody,
    jsonFeeder,
    feed,
    csv
} from "@gatling.io/core";
import {http, status} from "@gatling.io/http";

const credsFeeder = csv("../resources/creds.csv").random();

const httpProtocol = http
    .baseUrl("https://qa.myproject.co")
    .inferHtmlResources()
    .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36");

const headers_0 = {
    "Content-Type": "application/json",
    "Prefer": "timezone=Europe/Bratislava",
    "sec-ch-ua": "Google Chrome\";v=\"131\", \"Chromium\";v=\"131\", \"Not_A Brand\";v=\"24",
    "sec-ch-ua-mobile": "?0",
    "sec-ch-ua-platform": "macOS"
};

const scn = scenario("loginSF")
    .feed(credsFeeder)
    .exec(
        http("request_0")
            .post("/api/authentication/auth/sign_in")
            .headers(headers_0)
            .body(
                StringBody(`{
                    "login": "#{login}",
                    "password": "#{password}"
                }`)
            )
            .check(status().is(200)) // Check if the login is successful
    );

export default simulation((setUp) => {
    setUp(scn.injectOpen(atOnceUsers(10))).protocols(httpProtocol);
});

My creds.csv:

login,password
log1,pas1
log2,pas2

My simulation with json feeding:

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

const httpProtocol = http
    .baseUrl("https://qa.myproject.co")
    .inferHtmlResources()
    .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36");

const headers_0 = {
    "Content-Type": "application/json",
    "Prefer": "timezone=Europe/Bratislava",
    "sec-ch-ua": "Google Chrome\";v=\"131\", \"Chromium\";v=\"131\", \"Not_A Brand\";v=\"24",
    "sec-ch-ua-mobile": "?0",
    "sec-ch-ua-platform": "macOS",
};

const credsFeeder = jsonFeeder("../resources/creds.json").random();

const scn = scenario("loginSF")
    .feed(credsFeeder)  
    .exec(
        http("request_0")
            .post("/api/authentication/auth/sign_in")
            .headers(headers_0)
            .body((session) => {
                // Dynamically retrieve the login and password from the session
                const login = session.get("login");
                const password = session.get("password");
                return JSON.stringify({
                    login: login,   
                    password: password  
                });
            })
            .check(status().is(200))  
    );

export default simulation((setUp) => {
    setUp(scn.injectOpen(atOnceUsers(100))).protocols(httpProtocol);
});

My creds.json:

[
    {
        "login": "log1",
        "password": "pass1"
    },

    {
        "login": "log1",
        "password": "pass1"
    }
]

Both options work fine when there is only one key-value pair in .csv file/.json file

Full error log:

Run crashed
org.graalvm.polyglot.PolyglotException: TypeError: undefined is not a function
	at <js>.:=>(bundle.js:2893)
	at <js>.:program(bundle.js:1)
	at org.graalvm.polyglot.Context.eval(Context.java:402)
	at io.gatling.js.JsSimulationHelper.loadSimulation(JsSimulationHelper.java:64)
	at io.gatling.js.JsSimulation.<init>(JsSimulation.java:38)
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62)
	... 9 common frames omitted
Wrapped by: java.lang.reflect.InvocationTargetException: null
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:74)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:501)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:485)
	at io.gatling.app.SimulationClass$Java.params(SimulationClass.scala:47)
	at io.gatling.app.Runner.load(Runner.scala:73)
	at io.gatling.app.Runner.run(Runner.scala:58)
	at io.gatling.app.Gatling$.start(Gatling.scala:83)
	at io.gatling.app.Gatling$.fromArgs(Gatling.scala:46)
	at io.gatling.app.Gatling$.main(Gatling.scala:40)
	at io.gatling.app.Gatling.main(Gatling.scala)
Exception in thread "main" java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:74)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:501)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:485)
	at io.gatling.app.SimulationClass$Java.params(SimulationClass.scala:47)
	at io.gatling.app.Runner.load(Runner.scala:73)
	at io.gatling.app.Runner.run(Runner.scala:58)
	at io.gatling.app.Gatling$.start(Gatling.scala:83)
	at io.gatling.app.Gatling$.fromArgs(Gatling.scala:46)
	at io.gatling.app.Gatling$.main(Gatling.scala:40)
	at io.gatling.app.Gatling.main(Gatling.scala)
Caused by: org.graalvm.polyglot.PolyglotException: TypeError: undefined is not a function
	at <js>.:=>(bundle.js:2893)
	at <js>.:program(bundle.js:1)
	at org.graalvm.polyglot.Context.eval(Context.java:402)
	at io.gatling.js.JsSimulationHelper.loadSimulation(JsSimulationHelper.java:64)
	at io.gatling.js.JsSimulation.<init>(JsSimulation.java:38)
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62)
	... 9 more
/Users/anna/Documents/gatling-js/javascript/node_modules/@gatling.io/cli/target/java.js:33
                reject(Error("Gatling process finished with code " + code));
                       ^

Error: Gatling process finished with code 1
    at ChildProcess.<anonymous> (/Users/anna/Documents/gatling-js/javascript/node_modules/@gatling.io/cli/target/java.js:33:24)
    at ChildProcess.emit (node:events:513:28)
    at maybeClose (node:internal/child_process:1101:16)
    at ChildProcess._handle.onexit (node:internal/child_process:305:5)

slandelle · December 23, 2024, 9:15pm

I’ve fixed an import error in your CSV sample.

Then:

jsonFeeder("../resources/creds.json") is wrong. You must use paths contained in the resources folder, meaning directly jsonFeeder("creds.json") in this case.
the qa.structuretest.co can’t be resolved, I guess it’s an internal one. Please build a test that can be run by someone outside your organization, eg targeting https://httpbin.org/.

Hanna · December 23, 2024, 9:23pm

Thanks, @slandelle. But it is not about path, initially I used exactly “creds.json” path, and rechecked now too - same error

slandelle · December 23, 2024, 9:30pm

Please build a proper reproducer I can run on my side. I only bothered running your CSV sample with the import and path fixes and hitting google.com instead and it worked (100% 404 as expected, but Gatling was able to build the request bodies).

Hanna · December 23, 2024, 9:41pm

strange, I’ve just changed baseUrl to “https://google.com” and still see same error, Gatling is not able to build the request bodies:

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

const httpProtocol = http
    .baseUrl("https://google.com")
    .inferHtmlResources()
    .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36");

const headers_0 = {
  "Content-Type": "application/json",
  "Prefer": "timezone=Europe/Bratislava",
  "sec-ch-ua": "Google Chrome\";v=\"131\", \"Chromium\";v=\"131\", \"Not_A Brand\";v=\"24",
  "sec-ch-ua-mobile": "?0",
  "sec-ch-ua-platform": "macOS",
};

const credsFeeder = jsonFeeder("creds.json").random();

const scn = scenario("loginSF")
    .feed(credsFeeder)
    .exec(
        http("request_0")
            .post("/api/authentication/auth/sign_in")
            .headers(headers_0)
            .body((session) => {
              // Dynamically retrieve the login and password from the session
              const login = session.get("login");
              const password = session.get("password");
              return JSON.stringify({
                login: login,
                password: password
              });
            })
            .check(status().is(200))
    );

export default simulation((setUp) => {
  setUp(scn.injectOpen(atOnceUsers(100))).protocols(httpProtocol);
});

slandelle · December 23, 2024, 10:05pm

Your CSV sample was almost correct, except for the missing import and the path.

Your JSON sample has way more errors:

you must pass a StringBody (or another “Body” type) to body() => StringBody(your function)
it’s not jsonFeeder but jsonFile, see Gatling session scripting reference - feeders
missing imports for StringBody, feed, jsonFile

I’m not a JavaScript developper, but I would expect all these errors to be better reported when using TypeScript.

Hanna · December 24, 2024, 12:49pm

Thanks a lot @slandelle, it was perfect idea to use TypeScript. I modified just a bit my scripts and both scripts, using .json and .csv feeding, work perfectly. But when I run exactly the same 100% identical script with .csv feeding using JS, I still see this “undefined is not a function” error. So, apparently issue is not on my side in this case. So, it is just better to use TS, thanks!

slandelle · December 24, 2024, 1:14pm

No, really, your script is buggy.

Here’s the corrected version with the fixes I provided:

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

const credsFeeder = jsonFile("creds.json").random();

const httpProtocol = http
    .baseUrl("https://google.com")
    .inferHtmlResources()
    .userAgentHeader("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36");

const headers_0 = {
  "Content-Type": "application/json",
  "Prefer": "timezone=Europe/Bratislava",
  "sec-ch-ua": "Google Chrome\";v=\"131\", \"Chromium\";v=\"131\", \"Not_A Brand\";v=\"24",
  "sec-ch-ua-mobile": "?0",
  "sec-ch-ua-platform": "macOS",
};

const scn = scenario("loginSF")
    .feed(credsFeeder)
    .exec(
        http("request_0")
            .post("/api/authentication/auth/sign_in")
            .headers(headers_0)
            .body(
                StringBody(
                    (session) => {
                        // Dynamically retrieve the login and password from the session
                        const login = session.get("login");
                        const password = session.get("password");
                        return JSON.stringify({
                            login: login,
                            password: password
                        });
                    }
                )
            )
            .check(status().is(200))
    );

export default simulation((setUp) => {
  setUp(scn.injectOpen(atOnceUsers(100))).protocols(httpProtocol);
});

---- Global Information --------------------------------------------------------
> request count                                        100 (OK=0      KO=100   )
> min response time                                    171 (OK=-      KO=171   )
> max response time                                    296 (OK=-      KO=296   )
> mean response time                                   227 (OK=-      KO=227   )
> std deviation                                         30 (OK=-      KO=30    )
> response time 50th percentile                        224 (OK=-      KO=224   )
> response time 75th percentile                        252 (OK=-      KO=252   )
> response time 95th percentile                        266 (OK=-      KO=266   )
> response time 99th percentile                        296 (OK=-      KO=296   )
> mean requests/sec                                    100 (OK=-      KO=100   )
---- Response Time Distribution ------------------------------------------------
> t < 800 ms                                             0 (     0%)
> 800 ms <= t < 1200 ms                                  0 (     0%)
> t >= 1200 ms                                           0 (     0%)
> failed                                               100 (   100%)
---- Errors --------------------------------------------------------------------
> status.find.is(200), but actually found 404                       100 (100,0%)
================================================================================

Hanna · December 24, 2024, 1:22pm

ok) but my version also works:

import {
    simulation,
    scenario,
    csvFeeder,
    atOnceUsers,
    exec,
    csv,
    pause,
    css,
    feed,
    repeat,
    tryMax,
    rampUsers,
    StringBody,
    jsonFeeder,
    jsonFile
} from "@gatling.io/core";
import { http, status } from "@gatling.io/http";

const httpProtocol = http
    .baseUrl("https://google.com")
    .inferHtmlResources()
    .userAgentHeader(
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36"
    );

const headers_0 = {
    "Content-Type": "application/json",
    "Prefer": "timezone=Europe/Bratislava",
    "sec-ch-ua": 'Google Chrome";v="131", "Chromium";v="131", "Not_A Brand";v="24',
    "sec-ch-ua-mobile": "?0",
    "sec-ch-ua-platform": "macOS",
};

const credsFeeder = jsonFile("resources/creds.json").random();

const scn = scenario("RecordedSimulation")
    .feed(credsFeeder)
    .exec(
        http("request_0")
            .post("/api/authentication/auth/sign_in")
            .headers(headers_0)
            .body(
                StringBody('{"login": "#{login}", "password": "#{password}"}')
            )
            .check(status().is(200))
    );

export default simulation((setUp) => {
    setUp(scn.injectOpen(atOnceUsers(100))).protocols(httpProtocol);
});
================================================================================
---- Global Information --------------------------------------------------------
> request count                                        100 (OK=100    KO=0     )
> min response time                                   2267 (OK=2267   KO=-     )
> max response time                                  10143 (OK=10143  KO=-     )
> mean response time                                  7872 (OK=7872   KO=-     )
> std deviation                                       2001 (OK=2001   KO=-     )
> response time 50th percentile                       8438 (OK=8438   KO=-     )
> response time 75th percentile                       9653 (OK=9653   KO=-     )
> response time 95th percentile                      10003 (OK=10003  KO=-     )
> response time 99th percentile                      10143 (OK=10143  KO=-     )
> mean requests/sec                                   9.09 (OK=9.09   KO=-     )
---- Response Time Distribution ------------------------------------------------
> t < 800 ms                                             0 (     0%)
> 800 ms <= t < 1200 ms                                  0 (     0%)
> t >= 1200 ms                                         100 (   100%)
> failed                                                 0 (     0%)
================================================================================

system · January 23, 2025, 1:23pm

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"undefined is not a function" error when feeding my simulation with .json/.csv file

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