browserContext.addInitScript differs in behaviour depending on type of script

[ankur22]

Brief summary

browserContext.addInitScript differs in behaviour depending on type of script, e.g. if you pass in a string vs a non string.

xk6-browser version

v1.4.3

OS

NA

Chrome version

NA

Docker version and image (if applicable)

NA

Steps to reproduce the problem

This works as intended so Math.random is overridden and will always return 0:

  const browserContext = browser.newContext();
  browserContext.addInitScript("Math.random = function(){return 0}");

This will not work as intended so Math.random isn't overridden and returns a random number:

  const browserContext = browser.newContext();
  browserContext.addInitScript(Math.random = function(){return 0});

Expected behaviour

The behaviour should be the same, and match what currently happens when a string function is passed in.

Actual behaviour

The behaviour differs.

Tasks

Preview Give feedback

1. Update the type defs too. They need to reflect the change that not just string is accepted.