PayPal Express Checkout - Behat Mink UI test with Selenium 2 Driver

CheckoutWithPaypalContext.php

<?php 

class CheckoutWithPaypalContext extends MinkContext
{
    /**
     * @When /^I choose to pay with PayPal$/
     */
    public function iChooseToPayWithPayPal()
    {
        $this->findAndWaitForElementToBeVisibleThenClick("//a[@id = 'paypal']");

        sleep(5);

        // Okay, now we're in PayPal

        $page = $this->getSession()->getPage();

        $iframes = $page->findAll('xpath', '//iframe');

        /**
         * Get the first frame, there might be more than one.
         *
         * @var NodeElement $payPalIframe
         */
        $payPalIframe = $iframes[0];

        // Then we switch to it. Mink works on a document-by-document basis.
        $this->getSession()->getDriver()->switchToIFrame($payPalIframe->getAttribute('name'));

        $payPalEmail    = $page->findById('email');
        $payPalPassword = $page->findById('password');
        $doLogin        = $page->findById('btnLogin');

        $payPalEmail->setValue('[email protected]');
        $payPalPassword->setValue('420420');
        $doLogin->click();

        // Ridiculous, but PayPal takes a few seconds to process.
        sleep(10);

        $doConfirm = null;
        $iteration = 0;

        while (null === $doConfirm && $iteration <= 5) {
            ++$iteration;
            sleep(5);
            $doConfirm = $this->getSession()->getPage()->findById('confirmButtonTop');
        }

        $doConfirm->click();

        // Return back to the shop.
        $this->getSession()->wait(10000, '"undefined" !== typeof someVariableIKnowExistsOnlyOnMySite');
    }
}

Awesome, thanks for this! 👍

Hoo many thanks for this.
I must mention that I had to switch back from the iframe to the regular window after the login

$this->getSession()->getDriver()->switchToIFrame();