Codeception: Checking if an image is valid within an acceptance test

README.md

I know this is not bulletproof and a bit cumbersome but it's a start and much better than not testing them at all.

acceptance.suite.yml

# [...]
modules:
    enabled:
        - WebDriver:
            # [...]
        - Tests\Codeception\Support\Helper\Image:
            depends: PhpBrowser
# [...]

Image.php

<?php

// tests/Codeception/Support/Helper/Image.php

namespace Tests\Codeception\Support\Helper;

use Tests\Codeception\Support\Helper\Abstracted\PhpBrowserDependentModule;
use Codeception\Exception\ModuleException;

class Image extends PhpBrowserDependentModule
{
    protected static $imageRegEx = 'img[src="%s"]';
    protected static $imageAltRegEx = 'img[alt="%s"]';

    /**
     * Checks if a link to an image returns a successful response and also checks if the width and height
     * is larger than 0, if the image is a known format.
     *
     * @param $selector
     * @throws ModuleException
     */
    public function seeValidImage($selector)
    {
        $this->getModule('WebDriver')->seeElement($selector);
        $url = $this->getModule('WebDriver')->grabAttributeFrom($selector, 'src');

        $contents = $this->grabFile($url);

        $imageInfo = getimagesizefromstring($contents);

        $this->assertIsArray($imageInfo);

        list($width, $height) = array_slice($imageInfo, 0, 2);

        $this->assertGreaterThan(0, $width);
        $this->assertGreaterThan(0, $height);
    }

    /**
     * Checks if an image with a given URL is visible on the page (currently limited to img tags)
     *
     * @param $url
     * @throws ModuleException
     */
    public function seeImage($url)
    {
        // TODO: what about broken images?
        $selector = sprintf(self::$imageRegEx, $url);

        $this->getModule('WebDriver')->seeElement($selector);
    }

    /**
     * Checks if an image with a given URL is not visible on the page (currently limited to img tags)
     *
     * @param $url
     * @throws ModuleException
     */
    public function dontSeeImage($url)
    {
        // TODO: what about broken images?
        $selector = sprintf(self::$imageRegEx, $url);

        $this->getModule('WebDriver')->dontSeeElement($selector);
    }

    /**
     * Checks if an image with a given alt text is visible on the page (currently limited to img tags)
     *
     * @param $url
     * @throws ModuleException
     */
    public function seeImageWithAltText($altText)
    {
        // TODO: what about broken images?
        $selector = sprintf(self::$imageAltRegEx, $altText);

        $this->getModule('WebDriver')->seeElement($selector);
    }
}

PhpBrowserDependentModule.php

<?php

// tests/Codeception/Support/Helper/Abstracted/PhpBrowserDependentModule.php

namespace Tests\Codeception\Support\Helper\Abstracted;

use Tests\Codeception\Support\Page\Start;
use Codeception\Exception\ModuleException;
use Codeception\Lib\Interfaces\DependsOnModule;
use Codeception\Module;
use Codeception\Module\PhpBrowser;

/**
 * Class PhpBrowserModule
 * @package AppBundle\Tests\Codeception\Helper\Abstracted
 */
abstract class PhpBrowserDependentModule extends Module implements DependsOnModule
{
    // TODO: get this directly from symfony's config...
    protected const PHP_SESSION_ID = 'MOCKSESSID';

    /**
     * @var PhpBrowser
     */
    protected $phpBrowser;

    /**
     * @return array
     */
    public function _depends()
    {
        return [PhpBrowser::class => 'PhpBrowser is a mandatory dependency of this helper'];
    }

    /**
     * @param PhpBrowser $phpBrowser
     */
    public function _inject(PhpBrowser $phpBrowser)
    {
        $this->phpBrowser = $phpBrowser;
    }

    /**
     * @param $url
     * @return mixed|\Symfony\Component\DomCrawler\Crawler
     * @throws ModuleException
     * @throws \Codeception\Exception\ExternalUrlException
     */
    public function grabFile($url)
    {
        $phpBrowser = $this->getPhpBrowser();

        $contents = $phpBrowser->_request('GET', $url);
        $phpBrowser->seeResponseCodeIs(200);

        return $contents;
    }

    /**
     * @return PhpBrowser
     * @throws ModuleException
     */
    protected function getPhpBrowser()
    {
        // not sure where else to put this...
        // must be executed after the login via WebDriver has happened and before the first use of the PhpBrowser module
        if ($this->phpBrowser->client->getInternalRequest() === null) {
            $this->phpBrowser->amOnPage(Start::$url);

            $this->phpBrowser->setCookie(
                self::PHP_SESSION_ID,
                $this->getModule('WebDriver')->grabCookie(self::PHP_SESSION_ID)
            );
        }

        return $this->phpBrowser;
    }
}

SomeCest.php

<?php
// [...]

    // check if default user picture is set and visible
    $profileImageUrl = $I->grabAttributeFrom($profileEditPage::$profileImageSelector, 'src');
    $I->assertStringContainsString($profileEditPage::$profileImageDefaultFilename, $profileImageUrl);
    $I->seeValidImage($profileEditPage::$profileImageSelector);

// [...]