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

tests/src/Kernel/ReadinessValidation/VersionPolicy/SupportedBranchInstalledTest.php

+<?php
+
+namespace Drupal\Tests\automatic_updates\Kernel\ReadinessValidation\VersionPolicy;
+
+use Drupal\automatic_updates\Validator\VersionPolicy\SupportedBranchInstalled;
+use Drupal\Tests\automatic_updates\Kernel\AutomaticUpdatesKernelTestBase;
+
+/**
+ * @covers \Drupal\automatic_updates\Validator\VersionPolicy\SupportedBranchInstalled
+ *
+ * @group automatic_updates
+ */
+class SupportedBranchInstalledTest extends AutomaticUpdatesKernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['automatic_updates', 'update'];
+
+  /**
+   * Data provider for ::testSupportedBranchInstalled().
+   *
+   * @return array[]
+   *   Sets of arguments to pass to the test method.
+   */
+  public function providerSupportedBranchInstalled(): array {
+    return [
+      'supported minor installed' => [
+        '9.8.0',
+        [FALSE, TRUE],
+        [],
+      ],
+      // These two cases test a supported major version, but unsupported minor
+      // version.
+      'supported major installed, minor updates forbidden' => [
+        '9.6.1',
+        [FALSE],
+        [
+          'The currently installed version of Drupal core, 9.6.1, 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.',
+          'See the <a href="/admin/reports/updates">available updates page</a> for available updates.',
+        ],
+      ],
+      'supported major installed, minor updates allowed' => [
+        '9.6.1',
+        [TRUE],
+        [
+          'The currently installed version of Drupal core, 9.6.1, 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.',
+          'Use the <a href="/admin/modules/automatic-update">update form</a> to update to a supported version.',
+        ],
+      ],
+      'unsupported version installed' => [
+        '8.9.0',
+        [FALSE, TRUE],
+        [
+          'The currently installed version of Drupal core, 8.9.0, 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.',
+          'See the <a href="/admin/reports/updates">available updates page</a> for available updates.',
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * Tests that the installed version of Drupal must be in a supported branch.
+   *
+   * @param string $installed_version
+   *   The installed version of Drupal core.
+   * @param bool[] $allow_minor_updates
+   *   The values of the `allow_core_minor_updates` config setting that should
+   *   be tested.
+   * @param string[] $expected_errors
+   *   The expected error messages, if any.
+   *
+   * @dataProvider providerSupportedBranchInstalled
+   */
+  public function testSupportedBranchInstalled(string $installed_version, array $allow_minor_updates, array $expected_errors): void {
+    $this->setCoreVersion($installed_version);
+    $this->setReleaseMetadata([
+      'drupal' => __DIR__ . '/../../../../fixtures/release-history/drupal.9.8.2.xml',
+    ]);
+
+    $rule = SupportedBranchInstalled::create($this->container);
+
+    foreach ($allow_minor_updates as $setting) {
+      $this->config('automatic_updates.settings')
+        ->set('allow_core_minor_updates', $setting)
+        ->save();
+
+      $actual_errors = array_map('strval', $rule->validate($installed_version));
+      $this->assertSame($expected_errors, $actual_errors);
+    }
+  }
+
+}