BackwardCompatibilityTest.php

<?php

namespace Drupal\FunctionalJavascriptTests\Ajax;

use Drupal\FunctionalJavascriptTests\WebDriverTestBase;

/**
 * Tests the compatibility of the ajax.es6.js file.
 *
 * @group Ajax
 */
class BackwardCompatibilityTest extends WebDriverTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'js_ajax_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * Ensures Drupal.Ajax.element_settings BC layer.
     */
    public function testAjaxBackwardCompatibility() {
        $this->drupalGet('/js_ajax_test');
        $this->click('#edit-test-button');
        $this->assertSession()
            ->waitForElement('css', '#js_ajax_test_form_element');
        $elements = $this->cssSelect('#js_ajax_test_form_element');
        $this->assertCount(1, $elements);
        $json = $elements[0]->getText();
        $data = json_decode($json, TRUE);
        $this->assertEquals([
            'element_settings' => 'catbro',
            'elementSettings' => 'catbro',
        ], $data);
    }

}