class ConfigImporterTest

class ConfigImporterTest extends KernelTestBase {
  
  /**
   * The beginning of an import validation error.
   */
  const FAIL_MESSAGE = 'There were errors validating the config synchronization.';
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'config_test',
    'system',
    'config_import_test',
    'config_events_test',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    $this->installConfig([
      'system',
      'config_test',
    ]);
    // Installing config_test's default configuration pollutes the global
    // variable being used for recording hook invocations by this test already,
    // so it has to be cleared out manually.
    unset($GLOBALS['hook_config_test']);
    $this->copyConfig($this->container
      ->get('config.storage'), $this->container
      ->get('config.storage.sync'));
  }
  
  /**
   * Tests omission of module APIs for bare configuration operations.
   */
  public function testNoImport() : void {
    $dynamic_name = 'config_test.dynamic.dotted.default';
    // Verify the default configuration values exist.
    $config = $this->config($dynamic_name);
    $this->assertSame('dotted.default', $config->get('id'));
    // Verify that a bare $this->config() does not involve module APIs.
    $this->assertFalse(isset($GLOBALS['hook_config_test']));
  }
  
  /**
   * Tests that trying to import from empty sync configuration directory fails.
   */
  public function testEmptyImportFails() : void {
    $this->expectException(ConfigImporterException::class);
    $this->container
      ->get('config.storage.sync')
      ->deleteAll();
    $this->configImporter()
      ->import();
  }
  
  /**
   * Tests verification of site UUID before importing configuration.
   */
  public function testSiteUuidValidate() : void {
    $sync = \Drupal::service('config.storage.sync');
    // Create updated configuration object.
    $config_data = $this->config('system.site')
      ->get();
    // Generate a new site UUID.
    $config_data['uuid'] = \Drupal::service('uuid')->generate();
    $sync->write('system.site', $config_data);
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown, invalid import was not stopped due to mis-matching site UUID.');
    } catch (ConfigImporterException $e) {
      $actual_message = $e->getMessage();
      $actual_error_log = $config_importer->getErrors();
      $expected_error_log = [
        'Site UUID in source storage does not match the target storage.',
      ];
      $this->assertEquals($expected_error_log, $actual_error_log);
      $expected = static::FAIL_MESSAGE . PHP_EOL . 'Site UUID in source storage does not match the target storage.';
      $this->assertEquals($expected, $actual_message);
      foreach ($expected_error_log as $log_row) {
        $this->assertMatchesRegularExpression("/{$log_row}/", $actual_message);
      }
    }
  }
  
  /**
   * Tests deletion of configuration during import.
   */
  public function testDeleted() : void {
    $dynamic_name = 'config_test.dynamic.dotted.default';
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    // Verify the default configuration values exist.
    $config = $this->config($dynamic_name);
    $this->assertSame('dotted.default', $config->get('id'));
    // Delete the file from the sync directory.
    $sync->delete($dynamic_name);
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    // Verify the file has been removed.
    $this->assertFalse($storage->read($dynamic_name));
    $config = $this->config($dynamic_name);
    $this->assertNull($config->get('id'));
    // Verify that appropriate module API hooks have been invoked.
    $this->assertTrue(isset($GLOBALS['hook_config_test']['load']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['presave']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['insert']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['update']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['predelete']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['delete']));
    $this->assertFalse($config_importer->hasUnprocessedConfigurationChanges());
    $logs = $config_importer->getErrors();
    $this->assertCount(0, $logs);
  }
  
  /**
   * Tests creation of configuration during import.
   */
  public function testNew() : void {
    $dynamic_name = 'config_test.dynamic.new';
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    // Verify the configuration to create does not exist yet.
    $this->assertFalse($storage->exists($dynamic_name), $dynamic_name . ' not found.');
    // Create new config entity.
    $original_dynamic_data = [
      'uuid' => '30df59bd-7b03-4cf7-bb35-d42fc49f0651',
      'langcode' => \Drupal::languageManager()->getDefaultLanguage()
        ->getId(),
      'status' => TRUE,
      'dependencies' => [],
      'id' => 'new',
      'label' => 'New',
      'weight' => 0,
      'style' => '',
      'size' => '',
      'size_value' => '',
      'protected_property' => '',
    ];
    $sync->write($dynamic_name, $original_dynamic_data);
    $this->assertTrue($sync->exists($dynamic_name), $dynamic_name . ' found.');
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    // Verify the values appeared.
    $config = $this->config($dynamic_name);
    $this->assertSame($original_dynamic_data['label'], $config->get('label'));
    // Verify that appropriate module API hooks have been invoked.
    $this->assertFalse(isset($GLOBALS['hook_config_test']['load']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['presave']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['insert']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['update']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['predelete']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['delete']));
    // Verify that hook_config_import_steps_alter() can add steps to
    // configuration synchronization.
    $this->assertTrue(isset($GLOBALS['hook_config_test']['config_import_steps_alter']));
    // Verify that there is nothing more to import.
    $this->assertFalse($config_importer->hasUnprocessedConfigurationChanges());
    $logs = $config_importer->getErrors();
    $this->assertCount(0, $logs);
  }
  
  /**
   * Tests that secondary writes are overwritten.
   */
  public function testSecondaryWritePrimaryFirst() : void {
    $name_primary = 'config_test.dynamic.primary';
    $name_secondary = 'config_test.dynamic.secondary';
    $sync = $this->container
      ->get('config.storage.sync');
    $uuid = $this->container
      ->get('uuid');
    $values_primary = [
      'id' => 'primary',
      'label' => 'Primary',
      'weight' => 0,
      'uuid' => $uuid->generate(),
    ];
    $sync->write($name_primary, $values_primary);
    $values_secondary = [
      'id' => 'secondary',
      'label' => 'Secondary Sync',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on primary, to ensure that is synced first.
'dependencies' => [
        'config' => [
          $name_primary,
        ],
      ],
    ];
    $sync->write($name_secondary, $values_secondary);
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    $entity_storage = \Drupal::entityTypeManager()->getStorage('config_test');
    $primary = $entity_storage->load('primary');
    $this->assertEquals('primary', $primary->id());
    $this->assertEquals($values_primary['uuid'], $primary->uuid());
    $this->assertEquals($values_primary['label'], $primary->label());
    $secondary = $entity_storage->load('secondary');
    $this->assertEquals('secondary', $secondary->id());
    $this->assertEquals($values_secondary['uuid'], $secondary->uuid());
    $this->assertEquals($values_secondary['label'], $secondary->label());
    $logs = $config_importer->getErrors();
    $this->assertCount(1, $logs);
    $this->assertEquals('Deleted and replaced configuration entity "' . $name_secondary . '"', $logs[0]);
  }
  
  /**
   * Tests that secondary writes are overwritten.
   */
  public function testSecondaryWriteSecondaryFirst() : void {
    $name_primary = 'config_test.dynamic.primary';
    $name_secondary = 'config_test.dynamic.secondary';
    $sync = $this->container
      ->get('config.storage.sync');
    $uuid = $this->container
      ->get('uuid');
    $values_primary = [
      'id' => 'primary',
      'label' => 'Primary',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on secondary, so that is synced first.
'dependencies' => [
        'config' => [
          $name_secondary,
        ],
      ],
    ];
    $sync->write($name_primary, $values_primary);
    $values_secondary = [
      'id' => 'secondary',
      'label' => 'Secondary Sync',
      'weight' => 0,
      'uuid' => $uuid->generate(),
    ];
    $sync->write($name_secondary, $values_secondary);
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    $entity_storage = \Drupal::entityTypeManager()->getStorage('config_test');
    $primary = $entity_storage->load('primary');
    $this->assertEquals('primary', $primary->id());
    $this->assertEquals($values_primary['uuid'], $primary->uuid());
    $this->assertEquals($values_primary['label'], $primary->label());
    $secondary = $entity_storage->load('secondary');
    $this->assertEquals('secondary', $secondary->id());
    $this->assertEquals($values_secondary['uuid'], $secondary->uuid());
    $this->assertEquals($values_secondary['label'], $secondary->label());
    $logs = $config_importer->getErrors();
    $this->assertCount(1, $logs);
    $this->assertEquals(Html::escape("Unexpected error during import with operation create for {$name_primary}: 'config_test' entity with ID 'secondary' already exists."), $logs[0]);
  }
  
  /**
   * Tests that secondary updates for deleted files work as expected.
   */
  public function testSecondaryUpdateDeletedParentFirst() : void {
    $name_dependency = 'config_test.dynamic.dependency';
    $name_dependent = 'config_test.dynamic.dependent';
    $name_other = 'config_test.dynamic.other';
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    $uuid = $this->container
      ->get('uuid');
    $values_dependency = [
      'id' => 'dependency',
      'label' => 'Dependency',
      'weight' => 0,
      'uuid' => $uuid->generate(),
    ];
    $storage->write($name_dependency, $values_dependency);
    $values_dependency['label'] = 'Updated Dependency';
    $sync->write($name_dependency, $values_dependency);
    $values_dependent = [
      'id' => 'dependent',
      'label' => 'Dependent',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on dependency, to make sure that is synced first.
'dependencies' => [
        'config' => [
          $name_dependency,
        ],
      ],
    ];
    $storage->write($name_dependent, $values_dependent);
    $values_dependent['label'] = 'Updated Child';
    $sync->write($name_dependent, $values_dependent);
    // Ensure that import will continue after the error.
    $values_other = [
      'id' => 'other',
      'label' => 'Other',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on dependency, to make sure that is synced first. This
      // will also be synced after the dependent due to alphabetical ordering.
'dependencies' => [
        'config' => [
          $name_dependency,
        ],
      ],
    ];
    $storage->write($name_other, $values_other);
    $values_other['label'] = 'Updated other';
    $sync->write($name_other, $values_other);
    // Check update changelist order.
    $config_importer = $this->configImporter();
    $updates = $config_importer->getStorageComparer()
      ->getChangelist('update');
    $expected = [
      $name_dependency,
      $name_dependent,
      $name_other,
    ];
    $this->assertSame($expected, $updates);
    // Import.
    $config_importer->import();
    $entity_storage = \Drupal::entityTypeManager()->getStorage('config_test');
    $dependency = $entity_storage->load('dependency');
    $this->assertEquals('dependency', $dependency->id());
    $this->assertEquals($values_dependency['uuid'], $dependency->uuid());
    $this->assertEquals($values_dependency['label'], $dependency->label());
    // The dependent was deleted in
    // \Drupal\config_test\Entity\ConfigTest::postSave().
    $this->assertNull($entity_storage->load('dependent'));
    $other = $entity_storage->load('other');
    $this->assertEquals('other', $other->id());
    $this->assertEquals($values_other['uuid'], $other->uuid());
    $this->assertEquals($values_other['label'], $other->label());
    $logs = $config_importer->getErrors();
    $this->assertCount(1, $logs);
    $this->assertEquals('Update target "' . $name_dependent . '" is missing.', $logs[0]);
  }
  
  /**
   * Tests that secondary updates for deleted files work as expected.
   *
   * This test is completely hypothetical since we only support full
   * configuration tree imports. Therefore, any configuration updates that cause
   * secondary deletes should be reflected already in the staged configuration.
   */
  public function testSecondaryUpdateDeletedChildFirst() : void {
    $name_dependency = 'config_test.dynamic.dependency';
    $name_dependent = 'config_test.dynamic.dependent';
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    $uuid = $this->container
      ->get('uuid');
    $values_dependency = [
      'id' => 'dependency',
      'label' => 'Dependency',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on dependent, to make sure that is synced first.
'dependencies' => [
        'config' => [
          $name_dependent,
        ],
      ],
    ];
    $storage->write($name_dependency, $values_dependency);
    $values_dependency['label'] = 'Updated Dependency';
    $sync->write($name_dependency, $values_dependency);
    $values_dependent = [
      'id' => 'dependent',
      'label' => 'Dependent',
      'weight' => 0,
      'uuid' => $uuid->generate(),
    ];
    $storage->write($name_dependent, $values_dependent);
    $values_dependent['label'] = 'Updated Dependent';
    $sync->write($name_dependent, $values_dependent);
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    $entity_storage = \Drupal::entityTypeManager()->getStorage('config_test');
    // Both entities are deleted. ConfigTest::postSave() causes updates of the
    // dependency entity to delete the dependent entity. Since the dependency
    // depends on the dependent, removing the dependent causes the dependency to
    // be removed.
    $this->assertNull($entity_storage->load('dependency'));
    $this->assertNull($entity_storage->load('dependent'));
    $logs = $config_importer->getErrors();
    $this->assertCount(0, $logs);
  }
  
  /**
   * Tests that secondary deletes for deleted files work as expected.
   */
  public function testSecondaryDeletedChildSecond() : void {
    $name_dependency = 'config_test.dynamic.dependency';
    $name_dependent = 'config_test.dynamic.dependent';
    $storage = $this->container
      ->get('config.storage');
    $uuid = $this->container
      ->get('uuid');
    $values_dependency = [
      'id' => 'dependency',
      'label' => 'Dependency',
      'weight' => 0,
      'uuid' => $uuid->generate(),
      // Add a dependency on dependent, to make sure this delete is synced
      // first.
'dependencies' => [
        'config' => [
          $name_dependent,
        ],
      ],
    ];
    $storage->write($name_dependency, $values_dependency);
    $values_dependent = [
      'id' => 'dependent',
      'label' => 'Dependent',
      'weight' => 0,
      'uuid' => $uuid->generate(),
    ];
    $storage->write($name_dependent, $values_dependent);
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    $entity_storage = \Drupal::entityTypeManager()->getStorage('config_test');
    $this->assertNull($entity_storage->load('dependency'));
    $this->assertNull($entity_storage->load('dependent'));
    // The dependent entity does not exist as the delete worked and although the
    // delete occurred in \Drupal\config_test\Entity\ConfigTest::postDelete()
    // this does not matter.
    $logs = $config_importer->getErrors();
    $this->assertCount(0, $logs);
  }
  
  /**
   * Tests updating of configuration during import.
   */
  public function testUpdated() : void {
    $name = 'config_test.system';
    $dynamic_name = 'config_test.dynamic.dotted.default';
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    // Verify that the configuration objects to import exist.
    $this->assertTrue($storage->exists($name), $name . ' found.');
    $this->assertTrue($storage->exists($dynamic_name), $dynamic_name . ' found.');
    // Replace the file content of the existing configuration objects in the
    // sync directory.
    $original_name_data = [
      'foo' => 'beer',
    ];
    $sync->write($name, $original_name_data);
    $original_dynamic_data = $storage->read($dynamic_name);
    $original_dynamic_data['label'] = 'Updated';
    $sync->write($dynamic_name, $original_dynamic_data);
    // Verify the active configuration still returns the default values.
    $config = $this->config($name);
    $this->assertSame('bar', $config->get('foo'));
    $config = $this->config($dynamic_name);
    $this->assertSame('Default', $config->get('label'));
    // Import.
    $config_importer = $this->configImporter();
    $config_importer->import();
    // Verify the values were updated.
    \Drupal::configFactory()->reset($name);
    $config = $this->config($name);
    $this->assertSame('beer', $config->get('foo'));
    $config = $this->config($dynamic_name);
    $this->assertSame('Updated', $config->get('label'));
    // Verify that the original file content is still the same.
    $this->assertSame($original_name_data, $sync->read($name));
    $this->assertSame($original_dynamic_data, $sync->read($dynamic_name));
    // Verify that appropriate module API hooks have been invoked.
    $this->assertTrue(isset($GLOBALS['hook_config_test']['load']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['presave']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['insert']));
    $this->assertTrue(isset($GLOBALS['hook_config_test']['update']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['predelete']));
    $this->assertFalse(isset($GLOBALS['hook_config_test']['delete']));
    // Verify that there is nothing more to import.
    $this->assertFalse($config_importer->hasUnprocessedConfigurationChanges());
    $logs = $config_importer->getErrors();
    $this->assertCount(0, $logs);
  }
  
  /**
   * Tests the isInstallable method()
   */
  public function testIsInstallable() : void {
    $config_name = 'config_test.dynamic.is_installable';
    $this->assertFalse($this->container
      ->get('config.storage')
      ->exists($config_name));
    \Drupal::state()->set('config_test.is_installable', TRUE);
    $this->installConfig([
      'config_test',
    ]);
    $this->assertTrue($this->container
      ->get('config.storage')
      ->exists($config_name));
  }
  
  /**
   * Tests dependency validation during configuration import.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   * @see \Drupal\Core\Config\ConfigImporter::createExtensionChangelist()
   */
  public function testUnmetDependency() : void {
    $storage = $this->container
      ->get('config.storage');
    $sync = $this->container
      ->get('config.storage.sync');
    // Test an unknown configuration owner.
    $sync->write('unknown.config', [
      'test' => 'test',
    ]);
    // Make a config entity have unmet dependencies.
    $config_entity_data = $sync->read('config_test.dynamic.dotted.default');
    $config_entity_data['dependencies'] = [
      'module' => [
        'unknown',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.module', $config_entity_data);
    $config_entity_data['dependencies'] = [
      'theme' => [
        'unknown',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.theme', $config_entity_data);
    $config_entity_data['dependencies'] = [
      'config' => [
        'unknown',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.config', $config_entity_data);
    // Make an active config depend on something that is missing in sync.
    // The whole configuration needs to be consistent, not only the updated one.
    $config_entity_data['dependencies'] = [];
    $storage->write('config_test.dynamic.dotted.deleted', $config_entity_data);
    $config_entity_data['dependencies'] = [
      'config' => [
        'config_test.dynamic.dotted.deleted',
      ],
    ];
    $storage->write('config_test.dynamic.dotted.existing', $config_entity_data);
    $sync->write('config_test.dynamic.dotted.existing', $config_entity_data);
    $extensions = $sync->read('core.extension');
    // Add a module and a theme that do not exist.
    $extensions['module']['unknown_module'] = 0;
    $extensions['theme']['unknown_theme'] = 0;
    // Add a module and a theme that depend on uninstalled extensions.
    $extensions['module']['new_dependency_test'] = 0;
    $extensions['theme']['test_subtheme'] = 0;
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown; an invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $expected = [
        static::FAIL_MESSAGE,
        'Unable to install the <em class="placeholder">unknown_module</em> module since it does not exist.',
        'Unable to install the <em class="placeholder">New Dependency test</em> module since it requires the <em class="placeholder">New Dependency test with service</em> module.',
        'Unable to install the <em class="placeholder">unknown_theme</em> theme since it does not exist.',
        'Unable to install the <em class="placeholder">Theme test subtheme</em> theme since it requires the <em class="placeholder">Theme test base theme</em> theme.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.config</em> depends on the <em class="placeholder">unknown</em> configuration that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.existing</em> depends on the <em class="placeholder">config_test.dynamic.dotted.deleted</em> configuration that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.module</em> depends on the <em class="placeholder">unknown</em> module that will not be installed after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.theme</em> depends on the <em class="placeholder">unknown</em> theme that will not be installed after import.',
        'Configuration <em class="placeholder">unknown.config</em> depends on the <em class="placeholder">unknown</em> extension that will not be installed after import.',
      ];
      $this->assertEquals(implode(PHP_EOL, $expected), $e->getMessage());
      $error_log = $config_importer->getErrors();
      $expected = [
        'Unable to install the <em class="placeholder">unknown_module</em> module since it does not exist.',
        'Unable to install the <em class="placeholder">New Dependency test</em> module since it requires the <em class="placeholder">New Dependency test with service</em> module.',
        'Unable to install the <em class="placeholder">unknown_theme</em> theme since it does not exist.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.config</em> depends on the <em class="placeholder">unknown</em> configuration that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.existing</em> depends on the <em class="placeholder">config_test.dynamic.dotted.deleted</em> configuration that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.module</em> depends on the <em class="placeholder">unknown</em> module that will not be installed after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.theme</em> depends on the <em class="placeholder">unknown</em> theme that will not be installed after import.',
        'Configuration <em class="placeholder">unknown.config</em> depends on the <em class="placeholder">unknown</em> extension that will not be installed after import.',
      ];
      foreach ($expected as $expected_message) {
        $this->assertContainsEquals($expected_message, $error_log, $expected_message);
      }
    }
    // Make a config entity have multiple unmet dependencies.
    $config_entity_data = $sync->read('config_test.dynamic.dotted.default');
    $config_entity_data['dependencies'] = [
      'module' => [
        'unknown',
        'dblog',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.module', $config_entity_data);
    $config_entity_data['dependencies'] = [
      'theme' => [
        'unknown',
        'stark',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.theme', $config_entity_data);
    $config_entity_data['dependencies'] = [
      'config' => [
        'unknown',
        'unknown2',
      ],
    ];
    $sync->write('config_test.dynamic.dotted.config', $config_entity_data);
    $config_importer = $this->configImporter();
    try {
      $this->configImporter
        ->import();
      $this->fail('ConfigImporterException not thrown, invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $expected = [
        static::FAIL_MESSAGE,
        'Unable to install the <em class="placeholder">unknown_module</em> module since it does not exist.',
        'Unable to install the <em class="placeholder">New Dependency test</em> module since it requires the <em class="placeholder">New Dependency test with service</em> module.',
        'Unable to install the <em class="placeholder">unknown_theme</em> theme since it does not exist.',
        'Unable to install the <em class="placeholder">Theme test subtheme</em> theme since it requires the <em class="placeholder">Theme test base theme</em> theme.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.config</em> depends on configuration (<em class="placeholder">unknown, unknown2</em>) that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.existing</em> depends on the <em class="placeholder">config_test.dynamic.dotted.deleted</em> configuration that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.module</em> depends on modules (<em class="placeholder">unknown, Database Logging</em>) that will not be installed after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.theme</em> depends on themes (<em class="placeholder">unknown, Stark</em>) that will not be installed after import.',
        'Configuration <em class="placeholder">unknown.config</em> depends on the <em class="placeholder">unknown</em> extension that will not be installed after import.',
      ];
      $this->assertEquals(implode(PHP_EOL, $expected), $e->getMessage());
      $error_log = $config_importer->getErrors();
      $expected = [
        'Configuration <em class="placeholder">config_test.dynamic.dotted.config</em> depends on configuration (<em class="placeholder">unknown, unknown2</em>) that will not exist after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.module</em> depends on modules (<em class="placeholder">unknown, Database Logging</em>) that will not be installed after import.',
        'Configuration <em class="placeholder">config_test.dynamic.dotted.theme</em> depends on themes (<em class="placeholder">unknown, Stark</em>) that will not be installed after import.',
      ];
      foreach ($expected as $expected_message) {
        $this->assertContainsEquals($expected_message, $error_log, $expected_message);
      }
    }
  }
  
  /**
   * Tests missing core.extension during configuration import.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   */
  public function testMissingCoreExtension() : void {
    $sync = $this->container
      ->get('config.storage.sync');
    $sync->delete('core.extension');
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown, invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $expected = static::FAIL_MESSAGE . PHP_EOL . 'The core.extension configuration does not exist.';
      $this->assertEquals($expected, $e->getMessage());
      $error_log = $config_importer->getErrors();
      $this->assertEquals([
        'The core.extension configuration does not exist.',
      ], $error_log);
    }
  }
  
  /**
   * Tests uninstall validators being called during synchronization.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   */
  public function testRequiredModuleValidation() : void {
    $sync = $this->container
      ->get('config.storage.sync');
    $extensions = $sync->read('core.extension');
    unset($extensions['module']['system']);
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown, invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $this->assertStringContainsString('There were errors validating the config synchronization.', $e->getMessage());
      $error_log = $config_importer->getErrors();
      $this->assertEquals('Unable to uninstall the System module because: The System module is required.', $error_log[0]);
    }
  }
  
  /**
   * Tests installing a base themes and sub themes during configuration import.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   */
  public function testInstallBaseAndSubThemes() : void {
    $sync = $this->container
      ->get('config.storage.sync');
    $extensions = $sync->read('core.extension');
    $extensions['theme']['test_base_theme'] = 0;
    $extensions['theme']['test_subtheme'] = 0;
    $extensions['theme']['test_subsubtheme'] = 0;
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    $config_importer->import();
    $this->assertTrue($this->container
      ->get('theme_handler')
      ->themeExists('test_base_theme'));
    $this->assertTrue($this->container
      ->get('theme_handler')
      ->themeExists('test_subsubtheme'));
    $this->assertTrue($this->container
      ->get('theme_handler')
      ->themeExists('test_subtheme'));
    // Test uninstalling them.
    $extensions = $sync->read('core.extension');
    unset($extensions['theme']['test_base_theme']);
    unset($extensions['theme']['test_subsubtheme']);
    unset($extensions['theme']['test_subtheme']);
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    $config_importer->import();
    $this->assertFalse($this->container
      ->get('theme_handler')
      ->themeExists('test_base_theme'));
    $this->assertFalse($this->container
      ->get('theme_handler')
      ->themeExists('test_subsubtheme'));
    $this->assertFalse($this->container
      ->get('theme_handler')
      ->themeExists('test_subtheme'));
  }
  
  /**
   * Tests install profile validation during configuration import.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   */
  public function testInstallProfile() : void {
    $sync = $this->container
      ->get('config.storage.sync');
    $extensions = $sync->read('core.extension');
    // Add an install profile.
    $extensions['module']['standard'] = 0;
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown; an invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $expected = static::FAIL_MESSAGE . PHP_EOL . 'Unable to install the <em class="placeholder">standard</em> module since it does not exist.';
      $this->assertEquals($expected, $e->getMessage(), 'There were errors validating the config synchronization.');
      $error_log = $config_importer->getErrors();
      // Install profiles should not even be scanned at this point.
      $this->assertEquals([
        'Unable to install the standard module since it does not exist.',
      ], $error_log);
    }
  }
  
  /**
   * Tests install profile validation during configuration import.
   *
   * @see \Drupal\Core\EventSubscriber\ConfigImportSubscriber
   */
  public function testInstallProfileMisMatch() : void {
    // Install profiles can not be changed. They can only be uninstalled. We
    // need to set an install profile prior to testing because KernelTestBase
    // tests do not use one.
    $this->setInstallProfile('minimal');
    $sync = $this->container
      ->get('config.storage.sync');
    $extensions = $sync->read('core.extension');
    // Change the install profile.
    $extensions['profile'] = 'this_will_not_work';
    $sync->write('core.extension', $extensions);
    $config_importer = $this->configImporter();
    try {
      $config_importer->import();
      $this->fail('ConfigImporterException not thrown; an invalid import was not stopped due to missing dependencies.');
    } catch (ConfigImporterException $e) {
      $expected = static::FAIL_MESSAGE . PHP_EOL . 'Cannot change the install profile from <em class="placeholder">minimal</em> to <em class="placeholder">this_will_not_work</em> once Drupal is installed.';
      $this->assertEquals($expected, $e->getMessage(), 'There were errors validating the config synchronization.');
      $error_log = $config_importer->getErrors();
      $this->assertEquals([
        'Cannot change the install profile from minimal to this_will_not_work once Drupal is installed.',
      ], $error_log);
    }
  }
  
  /**
   * Tests the isSyncing flags.
   */
  public function testIsSyncingInHooks() : void {
    $dynamic_name = 'config_test.dynamic.dotted.default';
    $storage = $this->container
      ->get('config.storage');
    // Verify the default configuration values exist.
    $config = $this->config($dynamic_name);
    $this->assertSame('dotted.default', $config->get('id'));
    // Delete the config so that create hooks will fire.
    $storage->delete($dynamic_name);
    \Drupal::state()->set('config_test.store_isSyncing', []);
    $this->configImporter()
      ->import();
    // The values of the syncing values should be stored in state by
    // config_test_config_test_create().
    $state = \Drupal::state()->get('config_test.store_isSyncing');
    $this->assertTrue($state['global_state::create'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::create'], 'ConfigEntity::isSyncing() returns TRUE');
    $this->assertTrue($state['global_state::presave'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::presave'], 'ConfigEntity::isSyncing() returns TRUE');
    $this->assertTrue($state['global_state::insert'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::insert'], 'ConfigEntity::isSyncing() returns TRUE');
    // Cause a config update so update hooks will fire.
    $config = $this->config($dynamic_name);
    $config->set('label', 'A new name')
      ->save();
    \Drupal::state()->set('config_test.store_isSyncing', []);
    $this->configImporter()
      ->import();
    // The values of the syncing values should be stored in state by
    // config_test_config_test_create().
    $state = \Drupal::state()->get('config_test.store_isSyncing');
    $this->assertTrue($state['global_state::presave'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::presave'], 'ConfigEntity::isSyncing() returns TRUE');
    $this->assertTrue($state['global_state::update'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::update'], 'ConfigEntity::isSyncing() returns TRUE');
    // Cause a config delete so delete hooks will fire.
    $sync = $this->container
      ->get('config.storage.sync');
    $sync->delete($dynamic_name);
    \Drupal::state()->set('config_test.store_isSyncing', []);
    $this->configImporter()
      ->import();
    // The values of the syncing values should be stored in state by
    // config_test_config_test_create().
    $state = \Drupal::state()->get('config_test.store_isSyncing');
    $this->assertTrue($state['global_state::predelete'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::predelete'], 'ConfigEntity::isSyncing() returns TRUE');
    $this->assertTrue($state['global_state::delete'], '\\Drupal::isConfigSyncing() returns TRUE');
    $this->assertTrue($state['entity_state::delete'], 'ConfigEntity::isSyncing() returns TRUE');
    // Test that isSyncing is TRUE in hook_module_preinstall() and
    // hook_modules_installed() when installing a single module via config
    // import.
    $extensions = $sync->read('core.extension');
    // First, install system_test so that its hook_module_preinstall() will run
    // when module_test is installed.
    $this->container
      ->get('module_installer')
      ->install([
      'system_test',
    ]);
    // Add module_test and system_test to the enabled modules to be imported,
    // so that module_test gets installed on import and system_test does not get
    // uninstalled.
    $extensions['module']['module_test'] = 0;
    $extensions['module']['system_test'] = 0;
    $extensions['module'] = module_config_sort($extensions['module']);
    $sync->write('core.extension', $extensions);
    $this->configImporter()
      ->import();
    // Syncing values stored in state by hook_module_preinstall should be TRUE
    // when module is installed via config import.
    $this->assertTrue(\Drupal::state()->get('system_test_preinstall_module_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_module_preinstall() returns TRUE');
    $this->assertTrue(\Drupal::state()->get('system_test_preinstall_module_syncing_param'), 'system_test_module_preinstall() $is_syncing value is TRUE');
    // Syncing values stored in state by hook_modules_installed should be TRUE
    // when module is installed via config import.
    $this->assertTrue(\Drupal::state()->get('system_test_modules_installed_module_config_installer_syncing'));
    $this->assertTrue(\Drupal::state()->get('system_test_modules_installed_module_syncing_param'));
    // Reset the state values before testing multiple module install.
    \Drupal::state()->set('system_test_preinstall_module_config_installer_syncing', FALSE);
    \Drupal::state()->set('system_test_preinstall_module_syncing_param', FALSE);
    \Drupal::state()->set('system_test_modules_installed_module_config_installer_syncing', FALSE);
    \Drupal::state()->set('system_test_modules_installed_module_syncing_param', FALSE);
    // Test isSyncing is TRUE in hook_module_preinstall() and
    // hook_modules_installed() when installing multiple module via config
    // import.
    $extensions['module']['generic_module1_test'] = 0;
    $extensions['module']['generic_module2_test'] = 0;
    $sync->write('core.extension', $extensions);
    $this->configImporter()
      ->import();
    // Syncing values stored in state by hook_module_preinstall should be TRUE
    // when multiple modules are installed via config import.
    $this->assertTrue(\Drupal::state()->get('system_test_preinstall_module_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_module_preinstall() returns TRUE');
    $this->assertTrue(\Drupal::state()->get('system_test_preinstall_module_syncing_param'), 'system_test_module_preinstall() $is_syncing value is TRUE');
    // Syncing values stored in state by hook_modules_installed should be TRUE
    // when multiple modules are installed via config import.
    $this->assertTrue(\Drupal::state()->get('system_test_modules_installed_module_config_installer_syncing'));
    $this->assertTrue(\Drupal::state()->get('system_test_modules_installed_module_syncing_param'));
    // Syncing value stored in state by uninstall hooks should be FALSE
    // when uninstalling outside of config import.
    $this->container
      ->get('module_installer')
      ->uninstall([
      'module_test',
    ]);
    $this->assertFalse(\Drupal::state()->get('system_test_preuninstall_module_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_module_preuninstall() returns FALSE');
    $this->assertFalse(\Drupal::state()->get('system_test_preuninstall_module_syncing_param'), 'system_test_module_preuninstall() $is_syncing value is FALSE');
    $this->assertFalse(\Drupal::state()->get('system_test_modules_uninstalled_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_modules_uninstalled returns FALSE');
    $this->assertFalse(\Drupal::state()->get('system_test_modules_uninstalled_syncing_param'), 'system_test_modules_uninstalled $is_syncing value is FALSE');
    // Syncing value stored in state by hook_module_preinstall should be FALSE
    // when installing outside of config import.
    $this->container
      ->get('module_installer')
      ->install([
      'module_test',
    ]);
    $this->assertFalse(\Drupal::state()->get('system_test_preinstall_module_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_module_preinstall() returns TRUE');
    $this->assertFalse(\Drupal::state()->get('system_test_preinstall_module_syncing_param'), 'system_test_module_preinstall() $is_syncing value is TRUE');
    // Uninstall module_test via config import. Syncing value stored in state
    // by uninstall hooks should be TRUE.
    unset($extensions['module']['module_test']);
    $sync->write('core.extension', $extensions);
    $this->configImporter()
      ->import();
    $this->assertTrue(\Drupal::state()->get('system_test_preuninstall_module_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_module_preuninstall() returns TRUE');
    $this->assertTrue(\Drupal::state()->get('system_test_preuninstall_module_syncing_param'), 'system_test_module_preuninstall() $is_syncing value is TRUE');
    $this->assertTrue(\Drupal::state()->get('system_test_modules_uninstalled_config_installer_syncing'), '\\Drupal::isConfigSyncing() in system_test_modules_uninstalled returns TRUE');
    $this->assertTrue(\Drupal::state()->get('system_test_modules_uninstalled_syncing_param'), 'system_test_modules_uninstalled $is_syncing value is TRUE');
  }
  
  /**
   * Tests that the isConfigSyncing flag is cleanup after an invalid step.
   */
  public function testInvalidStep() : void {
    $this->assertFalse(\Drupal::isConfigSyncing(), 'Before an import \\Drupal::isConfigSyncing() returns FALSE');
    $context = [];
    $config_importer = $this->configImporter();
    try {
      $config_importer->doSyncStep('a_non_existent_step', $context);
      $this->fail('Expected \\InvalidArgumentException thrown');
    } catch (\InvalidArgumentException) {
      // Expected exception; just continue testing.
    }
    $this->assertFalse(\Drupal::isConfigSyncing(), 'After an invalid step \\Drupal::isConfigSyncing() returns FALSE');
  }
  
  /**
   * Tests that the isConfigSyncing flag is set correctly during a custom step.
   */
  public function testCustomStep() : void {
    $this->assertFalse(\Drupal::isConfigSyncing(), 'Before an import \\Drupal::isConfigSyncing() returns FALSE');
    $context = [];
    $this->configImporter()
      ->doSyncStep(self::customStep(...), $context);
    $this->assertTrue($context['is_syncing'], 'Inside a custom step \\Drupal::isConfigSyncing() returns TRUE');
    $this->assertFalse(\Drupal::isConfigSyncing(), 'After an valid custom step \\Drupal::isConfigSyncing() returns FALSE');
  }
  
  /**
   * Tests that uninstall a theme in config import correctly imports all config.
   */
  public function testUninstallThemeIncrementsCount() : void {
    $theme_installer = $this->container
      ->get('theme_installer');
    // Install our theme.
    $theme = 'test_base_theme';
    $theme_installer->install([
      $theme,
    ]);
    $this->assertTrue($this->container
      ->get('theme_handler')
      ->themeExists($theme));
    $sync = $this->container
      ->get('config.storage.sync');
    // Update 2 pieces of config in sync.
    $systemSiteName = 'system.site';
    $system = $sync->read($systemSiteName);
    $system['name'] = 'Foo';
    $sync->write($systemSiteName, $system);
    $cronName = 'system.cron';
    $cron = $sync->read($cronName);
    $this->assertTrue($cron['logging']);
    $cron['logging'] = FALSE;
    $sync->write($cronName, $cron);
    // Uninstall the theme in sync.
    $extensions = $sync->read('core.extension');
    unset($extensions['theme'][$theme]);
    $sync->write('core.extension', $extensions);
    $this->configImporter()
      ->import();
    // The theme should be uninstalled.
    $this->assertFalse($this->container
      ->get('theme_handler')
      ->themeExists($theme));
    // Both pieces of config should be updated.
    \Drupal::configFactory()->reset($systemSiteName);
    \Drupal::configFactory()->reset($cronName);
    $this->assertEquals('Foo', $this->config($systemSiteName)
      ->get('name'));
    $this->assertEquals(0, $this->config($cronName)
      ->get('logging'));
  }
  
  /**
   * Tests that installing a theme will reload all service dependencies.
   */
  public function testThemeInstallReloadsServices() : void {
    $this->assertFalse(\Drupal::service(ThemeHandlerInterface::class)->themeExists('test_base_theme'));
    $sync = $this->container
      ->get('config.storage.sync');
    // Ensure that the config import will install the theme.
    $extensions = $sync->read('core.extension');
    $extensions['theme']['test_base_theme'] = 0;
    $sync->write('core.extension', $extensions);
    $importer = $this->configImporter();
    $property = new \ReflectionProperty($importer, 'themeHandler');
    $old_theme_handler = $property->getValue($importer);
    $this->assertIsObject($old_theme_handler);
    $importer->import();
    $this->assertTrue(\Drupal::service(ThemeHandlerInterface::class)->themeExists('test_base_theme'));
    $new_theme_handler = $property->getValue($importer);
    $this->assertIsObject($new_theme_handler);
    $this->assertNotSame($old_theme_handler, $new_theme_handler);
  }
  
  /**
   * Tests config events during config import.
   */
  public function testConfigEvents() : void {
    $this->installConfig([
      'config_events_test',
    ]);
    $this->config('config_events_test.test')
      ->set('key', 'bar')
      ->save();
    $this->copyConfig($this->container
      ->get('config.storage'), $this->container
      ->get('config.storage.sync'));
    $this->config('config_events_test.test')
      ->set('key', 'foo')
      ->save();
    \Drupal::state()->set('config_events_test.event', []);
    // Import the configuration. This results in a save event with the value
    // changing from foo to bar.
    $this->configImporter()
      ->import();
    $event = \Drupal::state()->get('config_events_test.event', []);
    $this->assertSame(ConfigEvents::SAVE, $event['event_name']);
    $this->assertSame([
      'key' => 'bar',
    ], $event['current_config_data']);
    $this->assertSame([
      'key' => 'bar',
    ], $event['raw_config_data']);
    $this->assertSame([
      'key' => 'foo',
    ], $event['original_config_data']);
    // Import the configuration that deletes 'config_events_test.test'.
    $this->container
      ->get('config.storage.sync')
      ->delete('config_events_test.test');
    $this->configImporter()
      ->import();
    $this->assertFalse($this->container
      ->get('config.storage')
      ->exists('config_events_test.test'));
    $event = \Drupal::state()->get('config_events_test.event', []);
    $this->assertSame(ConfigEvents::DELETE, $event['event_name']);
    $this->assertSame([], $event['current_config_data']);
    $this->assertSame([], $event['raw_config_data']);
    $this->assertSame([
      'key' => 'bar',
    ], $event['original_config_data']);
  }
  
  /**
   * Tests events and collections during a config import.
   */
  public function testEventsAndCollectionsImport() : void {
    $collections = [
      'another_collection',
      'collection.test1',
      'collection.test2',
    ];
    // Set the event listener to return three possible collections.
    // @see \Drupal\config_collection_install_test\EventSubscriber
    \Drupal::state()->set('config_collection_install_test.collection_names', $collections);
    $this->enableModules([
      'config_collection_install_test',
    ]);
    $this->installConfig([
      'config_collection_install_test',
    ]);
    // Export the configuration and uninstall the module to test installing it
    // via configuration import.
    $this->copyConfig($this->container
      ->get('config.storage'), $this->container
      ->get('config.storage.sync'));
    $this->container
      ->get('module_installer')
      ->uninstall([
      'config_collection_install_test',
    ]);
    $this->assertEmpty($this->container
      ->get('config.storage')
      ->getAllCollectionNames());
    \Drupal::state()->set('config_events_test.all_events', []);
    $this->configImporter()
      ->import();
    $this->assertSame($collections, $this->container
      ->get('config.storage')
      ->getAllCollectionNames());
    $all_events = \Drupal::state()->get('config_events_test.all_events');
    $this->assertArrayHasKey('core.extension', $all_events[ConfigEvents::SAVE]);
    // Ensure that config in collections does not have the regular configuration
    // event triggered.
    $this->assertArrayNotHasKey('config_collection_install_test.test', $all_events[ConfigEvents::SAVE]);
    $this->assertCount(3, $all_events[ConfigCollectionEvents::SAVE_IN_COLLECTION]['config_collection_install_test.test']);
    $event_collections = [];
    foreach ($all_events[ConfigCollectionEvents::SAVE_IN_COLLECTION]['config_collection_install_test.test'] as $event) {
      $event_collections[] = $event['current_config_data']['collection'];
    }
    $this->assertSame($collections, $event_collections);
  }
  
  /**
   * Tests the target storage caching during configuration import.
   */
  public function testStorageComparerTargetStorage() : void {
    $this->installConfig([
      'config_events_test',
    ]);
    $this->copyConfig($this->container
      ->get('config.storage'), $this->container
      ->get('config.storage.sync'));
    $this->assertTrue($this->container
      ->get('module_installer')
      ->uninstall([
      'config_test',
    ]));
    \Drupal::state()->set('config_events_test.all_events', []);
    \Drupal::state()->set('config_test_install.foo_value', 'transient');
    // Prime the active config cache. If the ConfigImporter and StorageComparer
    // do not manage the target storage correctly this cache can pollute the
    // data.
    \Drupal::configFactory()->get('config_test.system');
    // Import the configuration. This results in a save event with the value
    // changing from foo to bar.
    $this->configImporter()
      ->import();
    $all_events = \Drupal::state()->get('config_events_test.all_events');
    // Test that the values change as expected during the configuration import.
    $this->assertCount(3, $all_events[ConfigEvents::SAVE]['config_test.system']);
    // First, the values are set by the module installer using the configuration
    // import's source storage.
    $this->assertSame([], $all_events[ConfigEvents::SAVE]['config_test.system'][0]['original_config_data']);
    $this->assertSame('bar', $all_events[ConfigEvents::SAVE]['config_test.system'][0]['current_config_data']['foo']);
    // Next, the config_test_install() function changes the value.
    $this->assertSame('bar', $all_events[ConfigEvents::SAVE]['config_test.system'][1]['original_config_data']['foo']);
    $this->assertSame('transient', $all_events[ConfigEvents::SAVE]['config_test.system'][1]['current_config_data']['foo']);
    // Last, the config importer processes all the configuration in the source
    // storage and ensures the values are as expected.
    $this->assertSame('transient', $all_events[ConfigEvents::SAVE]['config_test.system'][2]['original_config_data']['foo']);
    $this->assertSame('bar', $all_events[ConfigEvents::SAVE]['config_test.system'][2]['current_config_data']['foo']);
  }
  
  /**
   * Helper method to test custom config installer steps.
   *
   * @param array $context
   *   Batch context.
   * @param \Drupal\Core\Config\ConfigImporter $importer
   *   The config importer.
   */
  public static function customStep(array &$context, ConfigImporter $importer) : void {
    $context['is_syncing'] = \Drupal::isConfigSyncing();
  }

}