Whenever a child frame is attached or navigated in any page in the browser context. In this case, the script is evaluated in the context of the newly attached frame.
The script is evaluated after the document is created but before any of its scripts are run. This is useful to amend the JavaScript environment, for example, to override Math.random.
Returns
Type
Description
Promise<void>
A Promise that fulfills when the script has been added to the browser context.
Example
JavaScript
import{ browser }from'k6/browser';import{ check }from'https://jslib.k6.io/k6-utils/1.5.0/index.js';exportconst options ={scenarios:{browser:{executor:'shared-iterations',options:{browser:{type:'chromium',},},},},};exportdefaultasyncfunction(){const browserContext =await browser.newContext();// This will execute and override the existing implementation of Math.random.await browserContext.addInitScript('Math.random = function(){return 0}');const page =await browserContext.newPage();// In this example we are going to set the content manually, so we first// navigate to about:blank which will execute the init script, before setting// the content on the page.await page.goto('about:blank');await page.setContent(`
<html>
<head></head>
<body>
<div id="random">waiting...</div>
</body>
<script>
document.getElementById('random').textContent = Math.random();
</script>
</html>`);awaitcheck(page.locator('#random'),{'is zero':asyncrandom=>await random.textContent()=='0'});await page.close();}