Invalid option value exits with code 255 instead of 104 Invalid Config

[oleiade]

Brief summary

As a user, I would expect the following script to make k6 exit with code 104 (InvalidConfig):

 export const options = {
    vus: 'this is an invalid type',
}

export default function () {}

However, when running it, I get the following error message: ERRO[0000] could not initialize 'invalid-config.js': could not load JS test 'file:///Users/theocrevon/Dev/grafana/sandbox/k6-scripts/exitcodes/invalid-config.js': strconv.ParseInt: parsing "does not exist": invalid syntax, which I expect.

But echo $status (pardon the fish shell syntax) returns 255, which is uint8 for -1, which in my understanding is the "catch all" exit code.

k6 version

v0.51.0

OS

MacOS

Docker version and image (if applicable)

No response

Steps to reproduce the problem

k6 run the-script-above.js

Expected behaviour

As a user, I would expect this to set the exit code to 104 InvalidConfig.

Actual behaviour

Sets the exit code to 255 (uint8 equivalent of -1)

[ariasmn]

Hi! @oleiade

Had some free time and decided to open a PR to solve this issue (#3783)

PTAL and let me know what you think!