Mink + PhantomJS catch JavaScript Errors

BrowserContext.php

<?php

use Behat\MinkExtension\Context\MinkContext;
use Behat\Behat\Context\Context;
use Behat\Behat\Context\SnippetAcceptingContext;
use Behat\Gherkin\Node\PyStringNode;
use Behat\Gherkin\Node\TableNode;

/**
 * Defines application features from the specific context.
 */
class BrowserContext extends MinkContext implements Context, SnippetAcceptingContext
{

    /**
     * Initializes context.
     *
     * Every scenario gets its own context instance.
     * You can also pass arbitrary arguments to the
     * context constructor through behat.yml.
     */
    public function __construct()
    {

    }

    /**
     * @AfterStep
     * @javascript
     */
    public function checkJsErrors()
    {
        $errors = $this->getSession()->evaluateScript('return ErrorHandler.get();');
        if (is_array($errors) && count($errors) > 0) {
            $lastError = array_pop($errors);
            throw new \RuntimeException(sprintf(
                'JS error on page "%s". Message "%s", Filename "%s", Line %s',
                $this->getSession()->getCurrentUrl(),
                $lastError['message'],
                $lastError['filename'],
                $lastError['lineno']
            ));
        }
    }

    /**
     * @AfterScenario
     * @javascript
     */
    public function clearJsErrors()
    {
        $this->getSession()->executeScript('ErrorHandler.clear();');
    }
}

errorhandler.js

(function ($, w, stor) {

    var E = {
        storageKey: "error_handler",
        init: function () {
            $(w).on("error", E.handle);
        },
        handle: function (e) {
            if (typeof e.originalEvent !== "undefined") {
                var o = e.originalEvent;
                var error = {
                    message: o.message,
                    filename: o.filename,
                    lineno: o.lineno,
                };

                var errors = [];
                if (null !== stor.getItem(E.storageKey)) {
                    errors = JSON.parse(stor.getItem(E.storageKey));
                }

                errors.push(error);
                stor.setItem(E.storageKey, JSON.stringify(errors));
            }
        },
        get: function () {
            if (null !== stor.getItem(E.storageKey)) {
                return JSON.parse(stor.getItem(E.storageKey));
            }

            return [];
        },
        clear: function () {
            stor.setItem(E.storageKey, "[]");
        }
    };

    w.ErrorHandler = E;
    E.init();
}(jQuery, window, localStorage));

This save my day. Thanx a lot!