waitForEvent(event[, optionsOrPredicate])

Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Documentation

Open source

Waits for the event to fire and returns its value. If a predicate function has been set it will pass the value to the predicate function, which must return true for the promise to resolve.

Parameter	Type	Default	Description
event	string	`null`	Name of event to wait for. Currently the `'page'` event is the only one that is supported.
optionsOrPredicate	function\|object	`null`	Optional. If it’s a function, the `'page'` event data will be passed to it and it must return `true` to continue.
optionsOrPredicate.predicate	function	`null`	Optional. Function that will be called when the `'page'` event is emitted. The event data will be passed to it and it must return `true` to continue.
optionsOrPredicate.timeout	number	`30000`	Optional. Maximum time to wait in milliseconds.

Returns

Type	Description
`Promise<Object>`	At the moment a Page object is the only return value

Example

import { browser } from 'k6/experimental/browser';

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

export default async function () {
  const context = browser.newContext();

  // Call waitForEvent with a predicate which will return true once at least
  // one page has been created.
  let counter = 0;
  const promise = context.waitForEvent('page', {
    predicate: (page) => {
      if (++counter >= 1) {
        return true;
      }
      return false;
    },
  });

  // Now we create a page.
  const page = context.newPage();

  // Wait for the predicate to pass.
  await promise;
  console.log('predicate passed');

  page.close();
}