Issue #3275883: Warn if cron updates are enabled and the site is on an unsupported branch

src/Validator/SupportedBranchValidator.php

-<?php
-
-namespace Drupal\automatic_updates\Validator;
-
-use Drupal\automatic_updates\CronUpdater;
-use Drupal\automatic_updates\Event\ReadinessCheckEvent;
-use Drupal\automatic_updates\ProjectInfo;
-use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Extension\ExtensionVersion;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
-use Drupal\Core\StringTranslation\TranslationInterface;
-use Drupal\Core\Url;
-use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-
-/**
- * Validates that the installed core version is on a supported branch.
- *
- * @internal
- *   This class is an internal part of the module's update handling and
- *   should not be used by external code.
- */
-class SupportedBranchValidator implements EventSubscriberInterface {
-
-  use StringTranslationTrait;
-
-  /**
-   * The config factory service.
-   *
-   * @var \Drupal\Core\Config\ConfigFactoryInterface
-   */
-  protected $configFactory;
-
-  /**
-   * Constructs a SupportedBranchValidator object.
-   *
-   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
-   *   The translation service.
-   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
-   *   The config factory service.
-   */
-  public function __construct(TranslationInterface $translation, ConfigFactoryInterface $config_factory) {
-    $this->setStringTranslation($translation);
-    $this->configFactory = $config_factory;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function getSubscribedEvents() {
-    return [
-      ReadinessCheckEvent::class => 'checkBranchSupported',
-    ];
-  }
-
-  /**
-   * Validates the installed core version is in a supported branch.
-   *
-   * @param \Drupal\automatic_updates\Event\ReadinessCheckEvent $event
-   *   The readiness check event.
-   */
-  public function checkBranchSupported(ReadinessCheckEvent $event): void {
-    $stage = $event->getStage();
-    if (!($stage instanceof CronUpdater) || $stage->getMode() !== CronUpdater::DISABLED) {
-      return;
-    }
-    $project_info = new ProjectInfo('drupal');
-    $project_data = $project_info->getProjectInfo();
-    $installed_version_string = $project_info->getInstalledVersion();
-    $installed_version = ExtensionVersion::createFromVersionString($installed_version_string);
-    $supported_major = FALSE;
-    foreach (explode(',', $project_data['supported_branches']) as $supported_branch) {
-      $branch_version = ExtensionVersion::createFromSupportBranch($supported_branch);
-      if ($branch_version->getMajorVersion() === $installed_version->getMajorVersion()) {
-        if ($branch_version->getMinorVersion() === $installed_version->getMinorVersion()) {
-          return;
-        }
-        $supported_major = TRUE;
-      }
-    }
-    $messages[] = $this->t(
-      'The currently installed version of Drupal core, @version, is not in a supported minor version. Your site will not be automatically updated during cron until it is updated to a supported minor version.',
-      ['@version' => $installed_version_string]
-    );
-    if ($supported_major && $this->configFactory->get('automatic_updates.settings')->get('allow_core_minor_updates')) {
-      $messages[] = $this->t(
-        'Use the <a href=":update_url">update form</a> to update to a supported version.',
-        [':update_url' => Url::fromRoute('automatic_updates.module_update')->toString()]
-      );
-    }
-    else {
-      $messages[] = $this->t(
-        'See the <a href=":available_updates">available updates</a> page for available updates.',
-        [':available_updates' => Url::fromRoute('update.status')->toString()]
-      );
-    }
-    $event->addError(
-      [$messages],
-      $this->t('Install core version unsupported')
-    );
-  }
-
-}