RequiredTest.php

<?php

/**
 * @file
 * Definition of Drupal\system\Tests\Module\RequiredTest.
 */
namespace Drupal\system\Tests\Module;


/**
 * Test required modules functionality.
 */
class RequiredTest extends ModuleTestBase {
  public static function getInfo() {
    return array(
      'name' => 'Required modules',
      'description' => 'Attempt disabling of required modules.',
      'group' => 'Module',
    );
  }

  /**
   * Assert that core required modules cannot be disabled.
   */
  function testDisableRequired() {
    $module_info = system_get_info('module');
    $this
      ->drupalGet('admin/modules');
    foreach ($module_info as $module => $info) {

      // Check to make sure the checkbox for each required module is disabled
      // and checked (or absent from the page if the module is also hidden).
      if (!empty($info['required'])) {
        $field_name = "modules[{$info['package']}][{$module}][enable]";
        if (empty($info['hidden'])) {
          $this
            ->assertFieldByXPath("//input[@name='{$field_name}' and @disabled='disabled' and @checked='checked']", '', format_string('Field @name was disabled and checked.', array(
            '@name' => $field_name,
          )));
        }
        else {
          $this
            ->assertNoFieldByName($field_name);
        }
      }
    }
  }

}