evaluate(pageFunction[, arg])
Open source
evaluate(pageFunction[, arg])
Returns the value of the pageFunction
invocation.
Parameter | Type | Defaults | Description |
---|---|---|---|
pageFunction | function or string | Function to be evaluated in the page context. This can also be a string. | |
arg | string | '' | Optional argument to pass to pageFunction |
Returns
Type | Description |
---|---|
Promise<any> | The value of the pageFunction invocation. |
Example
JavaScript
import { browser } from 'k6/browser';
import { check } from 'k6/http';
export const options = {
scenarios: {
browser: {
executor: 'shared-iterations',
options: {
browser: {
type: 'chromium',
},
},
},
},
};
export default async function () {
const page = await browser.newPage();
await page.goto('https://test.k6.io/browser.php');
const dimensions = await page.evaluate(() => {
const obj = {
width: document.documentElement.clientWidth,
height: document.documentElement.clientHeight,
deviceScaleFactor: window.devicePixelRatio,
};
return obj;
});
check(dimensions, {
width: (d) => d.width === 1280,
height: (d) => d.height === 720,
scale: (d) => d.deviceScaleFactor === 1,
});
}
Was this page helpful?
Related documentation
Related resources from Grafana Labs
Additional helpful documentation, links, and articles:
60 min

Performance testing and observability in Grafana Cloud
In this webinar, learn how Grafana Cloud k6 offers you the best developer experience for performance testing.
60 min

User-centered observability: load testing, real user monitoring, and synthetics
Learn how to use load testing, synthetic monitoring, and real user monitoring (RUM) to understand end users' experience of your apps. Watch on demand.