evaluate(pageFunction[, arg])

Executes JavaScript code in the page, passing the matching element of the locator as the first argument to the pageFunction and arg as the following arguments. It returns the value of the pageFunction invocation.

Parameter	Type	Defaults	Description
pageFunction	function or string		Function to be evaluated in the page context.
arg	string	`''`	Optional argument to pass to `pageFunction`.

Returns

Type	Description
Promise	The return value of `pageFunction`.

Example

import { browser } from 'k6/browser';
import { check } from 'https://jslib.k6.io/k6-utils/1.5.0/index.js';

export const options = {
  scenarios: {
    browser: {
      executor: 'shared-iterations',
      options: {
        browser: {
          type: 'chromium',
        },
      },
    },
  },
};

export default async function () {
  const page = await browser.newPage();

  try {
    await page.goto("https://quickpizza.grafana.com", { waitUntil: "load" });

    await page.getByText('Pizza, Please!').click();

    await check(page, {
      'pizza name': async p => {
        const n = await p.locator('#pizza-name').evaluate((pizzaName, extra) => pizzaName.textContent + extra, ' Super pizza!');
        return n == 'Our recommendation: Super pizza!';
      }
    });
  } finally {
    await page.close();
  }
}