diff core/tests/Drupal/KernelTests/KernelTestBase.php @ 0:c75dbcec494b

Initial commit from drush-created site

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/tests/Drupal/KernelTests/KernelTestBase.php	Thu Jul 05 14:24:15 2018 +0000
@@ -0,0 +1,1117 @@
+<?php
+
+namespace Drupal\KernelTests;
+
+use Drupal\Component\FileCache\ApcuFileCacheBackend;
+use Drupal\Component\FileCache\FileCache;
+use Drupal\Component\FileCache\FileCacheFactory;
+use Drupal\Component\Utility\Html;
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Config\Development\ConfigSchemaChecker;
+use Drupal\Core\Database\Database;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\DependencyInjection\ServiceProviderInterface;
+use Drupal\Core\DrupalKernel;
+use Drupal\Core\Entity\Sql\SqlEntityStorageInterface;
+use Drupal\Core\Extension\ExtensionDiscovery;
+use Drupal\Core\Language\Language;
+use Drupal\Core\Site\Settings;
+use Drupal\Core\Test\TestDatabase;
+use Drupal\simpletest\AssertContentTrait;
+use Drupal\Tests\AssertHelperTrait;
+use Drupal\Tests\ConfigTestTrait;
+use Drupal\Tests\PhpunitCompatibilityTrait;
+use Drupal\Tests\RandomGeneratorTrait;
+use Drupal\Tests\TestRequirementsTrait;
+use Drupal\simpletest\TestServiceProvider;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\HttpFoundation\Request;
+use org\bovigo\vfs\vfsStream;
+use org\bovigo\vfs\visitor\vfsStreamPrintVisitor;
+
+/**
+ * Base class for functional integration tests.
+ *
+ * This base class should be useful for testing some types of integrations which
+ * don't require the overhead of a fully-installed Drupal instance, but which
+ * have many dependencies on parts of Drupal which can't or shouldn't be mocked.
+ *
+ * This base class partially boots a fixture Drupal. The state of the fixture
+ * Drupal is comparable to the state of a system during the early part of the
+ * installation process.
+ *
+ * Tests extending this base class can access services and the database, but the
+ * system is initially empty. This Drupal runs in a minimal mocked filesystem
+ * which operates within vfsStream.
+ *
+ * Modules specified in the $modules property are added to the service container
+ * for each test. The module/hook system is functional. Additional modules
+ * needed in a test should override $modules. Modules specified in this way will
+ * be added to those specified in superclasses.
+ *
+ * Unlike \Drupal\Tests\BrowserTestBase, the modules are not installed. They are
+ * loaded such that their services and hooks are available, but the install
+ * process has not been performed.
+ *
+ * Other modules can be made available in this way using
+ * KernelTestBase::enableModules().
+ *
+ * Some modules can be brought into a fully-installed state using
+ * KernelTestBase::installConfig(), KernelTestBase::installSchema(), and
+ * KernelTestBase::installEntitySchema(). Alternately, tests which need modules
+ * to be fully installed could inherit from \Drupal\Tests\BrowserTestBase.
+ *
+ * @see \Drupal\Tests\KernelTestBase::$modules
+ * @see \Drupal\Tests\KernelTestBase::enableModules()
+ * @see \Drupal\Tests\KernelTestBase::installConfig()
+ * @see \Drupal\Tests\KernelTestBase::installEntitySchema()
+ * @see \Drupal\Tests\KernelTestBase::installSchema()
+ * @see \Drupal\Tests\BrowserTestBase
+ */
+abstract class KernelTestBase extends TestCase implements ServiceProviderInterface {
+
+  use AssertLegacyTrait;
+  use AssertContentTrait;
+  use AssertHelperTrait;
+  use RandomGeneratorTrait;
+  use ConfigTestTrait;
+  use TestRequirementsTrait;
+  use PhpunitCompatibilityTrait;
+
+  /**
+   * {@inheritdoc}
+   *
+   * Back up and restore any global variables that may be changed by tests.
+   *
+   * @see self::runTestInSeparateProcess
+   */
+  protected $backupGlobals = TRUE;
+
+  /**
+   * {@inheritdoc}
+   *
+   * Kernel tests are run in separate processes because they allow autoloading
+   * of code from extensions. Running the test in a separate process isolates
+   * this behavior from other tests. Subclasses should not override this
+   * property.
+   */
+  protected $runTestInSeparateProcess = TRUE;
+
+  /**
+   * {@inheritdoc}
+   *
+   * Back up and restore static class properties that may be changed by tests.
+   *
+   * @see self::runTestInSeparateProcess
+   */
+  protected $backupStaticAttributes = TRUE;
+
+  /**
+   * {@inheritdoc}
+   *
+   * Contains a few static class properties for performance.
+   */
+  protected $backupStaticAttributesBlacklist = [
+    // Ignore static discovery/parser caches to speed up tests.
+    'Drupal\Component\Discovery\YamlDiscovery' => ['parsedFiles'],
+    'Drupal\Core\DependencyInjection\YamlFileLoader' => ['yaml'],
+    'Drupal\Core\Extension\ExtensionDiscovery' => ['files'],
+    'Drupal\Core\Extension\InfoParser' => ['parsedInfos'],
+    // Drupal::$container cannot be serialized.
+    'Drupal' => ['container'],
+    // Settings cannot be serialized.
+    'Drupal\Core\Site\Settings' => ['instance'],
+  ];
+
+  /**
+   * {@inheritdoc}
+   *
+   * Do not forward any global state from the parent process to the processes
+   * that run the actual tests.
+   *
+   * @see self::runTestInSeparateProcess
+   */
+  protected $preserveGlobalState = FALSE;
+
+  /**
+   * @var \Composer\Autoload\Classloader
+   */
+  protected $classLoader;
+
+  /**
+   * @var string
+   */
+  protected $siteDirectory;
+
+  /**
+   * @var string
+   */
+  protected $databasePrefix;
+
+  /**
+   * @var \Drupal\Core\DependencyInjection\ContainerBuilder
+   */
+  protected $container;
+
+  /**
+   * Modules to enable.
+   *
+   * The test runner will merge the $modules lists from this class, the class
+   * it extends, and so on up the class hierarchy. It is not necessary to
+   * include modules in your list that a parent class has already declared.
+   *
+   * @see \Drupal\Tests\KernelTestBase::enableModules()
+   * @see \Drupal\Tests\KernelTestBase::bootKernel()
+   *
+   * @var array
+   */
+  protected static $modules = [];
+
+  /**
+   * The virtual filesystem root directory.
+   *
+   * @var \org\bovigo\vfs\vfsStreamDirectory
+   */
+  protected $vfsRoot;
+
+  /**
+   * @var int
+   */
+  protected $expectedLogSeverity;
+
+  /**
+   * @var string
+   */
+  protected $expectedLogMessage;
+
+  /**
+   * @todo Move into Config test base class.
+   * @var \Drupal\Core\Config\ConfigImporter
+   */
+  protected $configImporter;
+
+  /**
+   * The app root.
+   *
+   * @var string
+   */
+  protected $root;
+
+  /**
+   * Set to TRUE to strict check all configuration saved.
+   *
+   * @see \Drupal\Core\Config\Development\ConfigSchemaChecker
+   *
+   * @var bool
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
+   * An array of config object names that are excluded from schema checking.
+   *
+   * @var string[]
+   */
+  protected static $configSchemaCheckerExclusions = [
+    // Following are used to test lack of or partial schema. Where partial
+    // schema is provided, that is explicitly tested in specific tests.
+    'config_schema_test.noschema',
+    'config_schema_test.someschema',
+    'config_schema_test.schema_data_types',
+    'config_schema_test.no_schema_data_types',
+    // Used to test application of schema to filtering of configuration.
+    'config_test.dynamic.system',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function setUpBeforeClass() {
+    parent::setUpBeforeClass();
+
+    // Change the current dir to DRUPAL_ROOT.
+    chdir(static::getDrupalRoot());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->root = static::getDrupalRoot();
+    $this->initFileCache();
+    $this->bootEnvironment();
+    $this->bootKernel();
+  }
+
+  /**
+   * Bootstraps a basic test environment.
+   *
+   * Should not be called by tests. Only visible for DrupalKernel integration
+   * tests.
+   *
+   * @see \Drupal\KernelTests\Core\DrupalKernel\DrupalKernelTest
+   * @internal
+   */
+  protected function bootEnvironment() {
+    $this->streamWrappers = [];
+    \Drupal::unsetContainer();
+
+    $this->classLoader = require $this->root . '/autoload.php';
+
+    require_once $this->root . '/core/includes/bootstrap.inc';
+
+    // Set up virtual filesystem.
+    Database::addConnectionInfo('default', 'test-runner', $this->getDatabaseConnectionInfo()['default']);
+    $test_db = new TestDatabase();
+    $this->siteDirectory = $test_db->getTestSitePath();
+
+    // Ensure that all code that relies on drupal_valid_test_ua() can still be
+    // safely executed. This primarily affects the (test) site directory
+    // resolution (used by e.g. LocalStream and PhpStorage).
+    $this->databasePrefix = $test_db->getDatabasePrefix();
+    drupal_valid_test_ua($this->databasePrefix);
+
+    $settings = [
+      'hash_salt' => get_class($this),
+      'file_public_path' => $this->siteDirectory . '/files',
+      // Disable Twig template caching/dumping.
+      'twig_cache' => FALSE,
+      // @see \Drupal\KernelTests\KernelTestBase::register()
+    ];
+    new Settings($settings);
+
+    $this->setUpFilesystem();
+
+    foreach (Database::getAllConnectionInfo() as $key => $targets) {
+      Database::removeConnection($key);
+    }
+    Database::addConnectionInfo('default', 'default', $this->getDatabaseConnectionInfo()['default']);
+  }
+
+  /**
+   * Sets up the filesystem, so things like the file directory.
+   */
+  protected function setUpFilesystem() {
+    $test_db = new TestDatabase($this->databasePrefix);
+    $test_site_path = $test_db->getTestSitePath();
+
+    $this->vfsRoot = vfsStream::setup('root');
+    $this->vfsRoot->addChild(vfsStream::newDirectory($test_site_path));
+    $this->siteDirectory = vfsStream::url('root/' . $test_site_path);
+
+    mkdir($this->siteDirectory . '/files', 0775);
+    mkdir($this->siteDirectory . '/files/config/' . CONFIG_SYNC_DIRECTORY, 0775, TRUE);
+
+    $settings = Settings::getInstance() ? Settings::getAll() : [];
+    $settings['file_public_path'] = $this->siteDirectory . '/files';
+    new Settings($settings);
+
+    $GLOBALS['config_directories'] = [
+      CONFIG_SYNC_DIRECTORY => $this->siteDirectory . '/files/config/sync',
+    ];
+  }
+
+  /**
+   * @return string
+   */
+  public function getDatabasePrefix() {
+    return $this->databasePrefix;
+  }
+
+  /**
+   * Bootstraps a kernel for a test.
+   */
+  private function bootKernel() {
+    $this->setSetting('container_yamls', []);
+    // Allow for test-specific overrides.
+    $settings_services_file = $this->root . '/sites/default/testing.services.yml';
+    if (file_exists($settings_services_file)) {
+      // Copy the testing-specific service overrides in place.
+      $testing_services_file = $this->siteDirectory . '/services.yml';
+      copy($settings_services_file, $testing_services_file);
+      $this->setSetting('container_yamls', [$testing_services_file]);
+    }
+
+    // Allow for global test environment overrides.
+    if (file_exists($test_env = $this->root . '/sites/default/testing.services.yml')) {
+      $GLOBALS['conf']['container_yamls']['testing'] = $test_env;
+    }
+    // Add this test class as a service provider.
+    $GLOBALS['conf']['container_service_providers']['test'] = $this;
+
+    $modules = self::getModulesToEnable(get_class($this));
+
+    // Prepare a precompiled container for all tests of this class.
+    // Substantially improves performance, since ContainerBuilder::compile()
+    // is very expensive. Encourages testing best practices (small tests).
+    // Normally a setUpBeforeClass() operation, but object scope is required to
+    // inject $this test class instance as a service provider (see above).
+    $rc = new \ReflectionClass(get_class($this));
+    $test_method_count = count(array_filter($rc->getMethods(), function ($method) {
+      // PHPUnit's @test annotations are intentionally ignored/not supported.
+      return strpos($method->getName(), 'test') === 0;
+    }));
+
+    // Bootstrap the kernel. Do not use createFromRequest() to retain Settings.
+    $kernel = new DrupalKernel('testing', $this->classLoader, FALSE);
+    $kernel->setSitePath($this->siteDirectory);
+    // Boot a new one-time container from scratch. Ensure to set the module list
+    // upfront to avoid a subsequent rebuild.
+    if ($modules && $extensions = $this->getExtensionsForModules($modules)) {
+      $kernel->updateModules($extensions, $extensions);
+    }
+    // DrupalKernel::boot() is not sufficient as it does not invoke preHandle(),
+    // which is required to initialize legacy global variables.
+    $request = Request::create('/');
+    $kernel->prepareLegacyRequest($request);
+
+    // register() is only called if a new container was built/compiled.
+    $this->container = $kernel->getContainer();
+
+    // Ensure database tasks have been run.
+    require_once __DIR__ . '/../../../includes/install.inc';
+    $connection = Database::getConnection();
+    $errors = db_installer_object($connection->driver())->runTasks();
+    if (!empty($errors)) {
+      $this->fail('Failed to run installer database tasks: ' . implode(', ', $errors));
+    }
+
+    if ($modules) {
+      $this->container->get('module_handler')->loadAll();
+    }
+
+    $this->container->get('request_stack')->push($request);
+
+    // Setup the destion to the be frontpage by default.
+    \Drupal::destination()->set('/');
+
+    // Write the core.extension configuration.
+    // Required for ConfigInstaller::installDefaultConfig() to work.
+    $this->container->get('config.storage')->write('core.extension', [
+      'module' => array_fill_keys($modules, 0),
+      'theme' => [],
+      'profile' => '',
+    ]);
+
+    $settings = Settings::getAll();
+    $settings['php_storage']['default'] = [
+      'class' => '\Drupal\Component\PhpStorage\FileStorage',
+    ];
+    new Settings($settings);
+
+    // Manually configure the test mail collector implementation to prevent
+    // tests from sending out emails and collect them in state instead.
+    // While this should be enforced via settings.php prior to installation,
+    // some tests expect to be able to test mail system implementations.
+    $GLOBALS['config']['system.mail']['interface']['default'] = 'test_mail_collector';
+
+    // Manually configure the default file scheme so that modules that use file
+    // functions don't have to install system and its configuration.
+    // @see file_default_scheme()
+    $GLOBALS['config']['system.file']['default_scheme'] = 'public';
+  }
+
+  /**
+   * Configuration accessor for tests. Returns non-overridden configuration.
+   *
+   * @param string $name
+   *   The configuration name.
+   *
+   * @return \Drupal\Core\Config\Config
+   *   The configuration object with original configuration data.
+   */
+  protected function config($name) {
+    return $this->container->get('config.factory')->getEditable($name);
+  }
+
+  /**
+   * Returns the Database connection info to be used for this test.
+   *
+   * This method only exists for tests of the Database component itself, because
+   * they require multiple database connections. Each SQLite :memory: connection
+   * creates a new/separate database in memory. A shared-memory SQLite file URI
+   * triggers PHP open_basedir/allow_url_fopen/allow_url_include restrictions.
+   * Due to that, Database tests are running against a SQLite database that is
+   * located in an actual file in the system's temporary directory.
+   *
+   * Other tests should not override this method.
+   *
+   * @return array
+   *   A Database connection info array.
+   *
+   * @internal
+   */
+  protected function getDatabaseConnectionInfo() {
+    // If the test is run with argument dburl then use it.
+    $db_url = getenv('SIMPLETEST_DB');
+    if (empty($db_url)) {
+      throw new \Exception('There is no database connection so no tests can be run. You must provide a SIMPLETEST_DB environment variable to run PHPUnit based functional tests outside of run-tests.sh. See https://www.drupal.org/node/2116263#skipped-tests for more information.');
+    }
+    else {
+      $database = Database::convertDbUrlToConnectionInfo($db_url, $this->root);
+      Database::addConnectionInfo('default', 'default', $database);
+    }
+
+    // Clone the current connection and replace the current prefix.
+    $connection_info = Database::getConnectionInfo('default');
+    if (!empty($connection_info)) {
+      Database::renameConnection('default', 'simpletest_original_default');
+      foreach ($connection_info as $target => $value) {
+        // Replace the full table prefix definition to ensure that no table
+        // prefixes of the test runner leak into the test.
+        $connection_info[$target]['prefix'] = [
+          'default' => $value['prefix']['default'] . $this->databasePrefix,
+        ];
+      }
+    }
+    return $connection_info;
+  }
+
+  /**
+   * Initializes the FileCache component.
+   *
+   * We can not use the Settings object in a component, that's why we have to do
+   * it here instead of \Drupal\Component\FileCache\FileCacheFactory.
+   */
+  protected function initFileCache() {
+    $configuration = Settings::get('file_cache');
+
+    // Provide a default configuration, if not set.
+    if (!isset($configuration['default'])) {
+      // @todo Use extension_loaded('apcu') for non-testbot
+      //  https://www.drupal.org/node/2447753.
+      if (function_exists('apcu_fetch')) {
+        $configuration['default']['cache_backend_class'] = ApcuFileCacheBackend::class;
+      }
+    }
+    FileCacheFactory::setConfiguration($configuration);
+    FileCacheFactory::setPrefix(Settings::getApcuPrefix('file_cache', $this->root));
+  }
+
+  /**
+   * Returns Extension objects for $modules to enable.
+   *
+   * @param string[] $modules
+   *   The list of modules to enable.
+   *
+   * @return \Drupal\Core\Extension\Extension[]
+   *   Extension objects for $modules, keyed by module name.
+   *
+   * @throws \PHPUnit_Framework_Exception
+   *   If a module is not available.
+   *
+   * @see \Drupal\Tests\KernelTestBase::enableModules()
+   * @see \Drupal\Core\Extension\ModuleHandler::add()
+   */
+  private function getExtensionsForModules(array $modules) {
+    $extensions = [];
+    $discovery = new ExtensionDiscovery($this->root);
+    $discovery->setProfileDirectories([]);
+    $list = $discovery->scan('module');
+    foreach ($modules as $name) {
+      if (!isset($list[$name])) {
+        throw new \PHPUnit_Framework_Exception("Unavailable module: '$name'. If this module needs to be downloaded separately, annotate the test class with '@requires module $name'.");
+      }
+      $extensions[$name] = $list[$name];
+    }
+    return $extensions;
+  }
+
+  /**
+   * Registers test-specific services.
+   *
+   * Extend this method in your test to register additional services. This
+   * method is called whenever the kernel is rebuilt.
+   *
+   * @param \Drupal\Core\DependencyInjection\ContainerBuilder $container
+   *   The service container to enhance.
+   *
+   * @see \Drupal\Tests\KernelTestBase::bootKernel()
+   */
+  public function register(ContainerBuilder $container) {
+    // Keep the container object around for tests.
+    $this->container = $container;
+
+    $container
+      ->register('flood', 'Drupal\Core\Flood\MemoryBackend')
+      ->addArgument(new Reference('request_stack'));
+    $container
+      ->register('lock', 'Drupal\Core\Lock\NullLockBackend');
+    $container
+      ->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory');
+    $container
+      ->register('keyvalue.memory', 'Drupal\Core\KeyValueStore\KeyValueMemoryFactory')
+      // Must persist container rebuilds, or all data would vanish otherwise.
+      ->addTag('persist');
+    $container
+      ->setAlias('keyvalue', 'keyvalue.memory');
+
+    // Set the default language on the minimal container.
+    $container->setParameter('language.default_values', Language::$defaultValues);
+
+    if ($this->strictConfigSchema) {
+      $container
+        ->register('simpletest.config_schema_checker', ConfigSchemaChecker::class)
+        ->addArgument(new Reference('config.typed'))
+        ->addArgument($this->getConfigSchemaExclusions())
+        ->addTag('event_subscriber');
+    }
+
+    if ($container->hasDefinition('path_processor_alias')) {
+      // Prevent the alias-based path processor, which requires a url_alias db
+      // table, from being registered to the path processor manager. We do this
+      // by removing the tags that the compiler pass looks for. This means the
+      // url generator can safely be used within tests.
+      $container->getDefinition('path_processor_alias')
+        ->clearTag('path_processor_inbound')
+        ->clearTag('path_processor_outbound');
+    }
+
+    if ($container->hasDefinition('password')) {
+      $container->getDefinition('password')
+        ->setArguments([1]);
+    }
+    TestServiceProvider::addRouteProvider($container);
+  }
+
+  /**
+   * Gets the config schema exclusions for this test.
+   *
+   * @return string[]
+   *   An array of config object names that are excluded from schema checking.
+   */
+  protected function getConfigSchemaExclusions() {
+    $class = get_class($this);
+    $exceptions = [];
+    while ($class) {
+      if (property_exists($class, 'configSchemaCheckerExclusions')) {
+        $exceptions = array_merge($exceptions, $class::$configSchemaCheckerExclusions);
+      }
+      $class = get_parent_class($class);
+    }
+    // Filter out any duplicates.
+    return array_unique($exceptions);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function assertPostConditions() {
+    // Execute registered Drupal shutdown functions prior to tearing down.
+    // @see _drupal_shutdown_function()
+    $callbacks = &drupal_register_shutdown_function();
+    while ($callback = array_shift($callbacks)) {
+      call_user_func_array($callback['callback'], $callback['arguments']);
+    }
+
+    // Shut down the kernel (if bootKernel() was called).
+    // @see \Drupal\KernelTests\Core\DrupalKernel\DrupalKernelTest
+    if ($this->container) {
+      $this->container->get('kernel')->shutdown();
+    }
+
+    // Fail in case any (new) shutdown functions exist.
+    $this->assertCount(0, drupal_register_shutdown_function(), 'Unexpected Drupal shutdown callbacks exist after running shutdown functions.');
+
+    parent::assertPostConditions();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function tearDown() {
+    // Destroy the testing kernel.
+    if (isset($this->kernel)) {
+      $this->kernel->shutdown();
+    }
+
+    // Remove all prefixed tables.
+    $original_connection_info = Database::getConnectionInfo('simpletest_original_default');
+    $original_prefix = $original_connection_info['default']['prefix']['default'];
+    $test_connection_info = Database::getConnectionInfo('default');
+    $test_prefix = $test_connection_info['default']['prefix']['default'];
+    if ($original_prefix != $test_prefix) {
+      $tables = Database::getConnection()->schema()->findTables('%');
+      foreach ($tables as $table) {
+        if (Database::getConnection()->schema()->dropTable($table)) {
+          unset($tables[$table]);
+        }
+      }
+    }
+
+    // Free up memory: Own properties.
+    $this->classLoader = NULL;
+    $this->vfsRoot = NULL;
+    $this->configImporter = NULL;
+
+    // Free up memory: Custom test class properties.
+    // Note: Private properties cannot be cleaned up.
+    $rc = new \ReflectionClass(__CLASS__);
+    $blacklist = [];
+    foreach ($rc->getProperties() as $property) {
+      $blacklist[$property->name] = $property->getDeclaringClass()->name;
+    }
+    $rc = new \ReflectionClass($this);
+    foreach ($rc->getProperties(\ReflectionProperty::IS_PUBLIC | \ReflectionProperty::IS_PROTECTED) as $property) {
+      if (!$property->isStatic() && !isset($blacklist[$property->name])) {
+        $this->{$property->name} = NULL;
+      }
+    }
+
+    // Clean FileCache cache.
+    FileCache::reset();
+
+    // Clean up statics, container, and settings.
+    if (function_exists('drupal_static_reset')) {
+      drupal_static_reset();
+    }
+    \Drupal::unsetContainer();
+    $this->container = NULL;
+    new Settings([]);
+
+    parent::tearDown();
+  }
+
+  /**
+   * @after
+   *
+   * Additional tear down method to close the connection at the end.
+   */
+  public function tearDownCloseDatabaseConnection() {
+    // Destroy the database connection, which for example removes the memory
+    // from sqlite in memory.
+    foreach (Database::getAllConnectionInfo() as $key => $targets) {
+      Database::removeConnection($key);
+    }
+  }
+
+  /**
+   * Installs default configuration for a given list of modules.
+   *
+   * @param string|string[] $modules
+   *   A module or list of modules for which to install default configuration.
+   *
+   * @throws \LogicException
+   *   If any module in $modules is not enabled.
+   */
+  protected function installConfig($modules) {
+    foreach ((array) $modules as $module) {
+      if (!$this->container->get('module_handler')->moduleExists($module)) {
+        throw new \LogicException("$module module is not enabled.");
+      }
+      $this->container->get('config.installer')->installDefaultConfig('module', $module);
+    }
+  }
+
+  /**
+   * Installs database tables from a module schema definition.
+   *
+   * @param string $module
+   *   The name of the module that defines the table's schema.
+   * @param string|array $tables
+   *   The name or an array of the names of the tables to install.
+   *
+   * @throws \LogicException
+   *   If $module is not enabled or the table schema cannot be found.
+   */
+  protected function installSchema($module, $tables) {
+    // drupal_get_module_schema() is technically able to install a schema
+    // of a non-enabled module, but its ability to load the module's .install
+    // file depends on many other factors. To prevent differences in test
+    // behavior and non-reproducible test failures, we only allow the schema of
+    // explicitly loaded/enabled modules to be installed.
+    if (!$this->container->get('module_handler')->moduleExists($module)) {
+      throw new \LogicException("$module module is not enabled.");
+    }
+    $tables = (array) $tables;
+    foreach ($tables as $table) {
+      $schema = drupal_get_module_schema($module, $table);
+      if (empty($schema)) {
+        // BC layer to avoid some contrib tests to fail.
+        // @todo Remove the BC layer before 8.1.x release.
+        // @see https://www.drupal.org/node/2670360
+        // @see https://www.drupal.org/node/2670454
+        if ($module == 'system') {
+          continue;
+        }
+        throw new \LogicException("$module module does not define a schema for table '$table'.");
+      }
+      $this->container->get('database')->schema()->createTable($table, $schema);
+    }
+  }
+
+  /**
+   * Installs the storage schema for a specific entity type.
+   *
+   * @param string $entity_type_id
+   *   The ID of the entity type.
+   */
+  protected function installEntitySchema($entity_type_id) {
+    /** @var \Drupal\Core\Entity\EntityManagerInterface $entity_manager */
+    $entity_manager = $this->container->get('entity.manager');
+    $entity_type = $entity_manager->getDefinition($entity_type_id);
+    $entity_manager->onEntityTypeCreate($entity_type);
+
+    // For test runs, the most common storage backend is a SQL database. For
+    // this case, ensure the tables got created.
+    $storage = $entity_manager->getStorage($entity_type_id);
+    if ($storage instanceof SqlEntityStorageInterface) {
+      $tables = $storage->getTableMapping()->getTableNames();
+      $db_schema = $this->container->get('database')->schema();
+      $all_tables_exist = TRUE;
+      foreach ($tables as $table) {
+        if (!$db_schema->tableExists($table)) {
+          $this->fail(SafeMarkup::format('Installed entity type table for the %entity_type entity type: %table', [
+            '%entity_type' => $entity_type_id,
+            '%table' => $table,
+          ]));
+          $all_tables_exist = FALSE;
+        }
+      }
+      if ($all_tables_exist) {
+        $this->pass(SafeMarkup::format('Installed entity type tables for the %entity_type entity type: %tables', [
+          '%entity_type' => $entity_type_id,
+          '%tables' => '{' . implode('}, {', $tables) . '}',
+        ]));
+      }
+    }
+  }
+
+  /**
+   * Enables modules for this test.
+   *
+   * This method does not install modules fully. Services and hooks for the
+   * module are available, but the install process is not performed.
+   *
+   * To install test modules outside of the testing environment, add
+   * @code
+   * $settings['extension_discovery_scan_tests'] = TRUE;
+   * @endcode
+   * to your settings.php.
+   *
+   * @param string[] $modules
+   *   A list of modules to enable. Dependencies are not resolved; i.e.,
+   *   multiple modules have to be specified individually. The modules are only
+   *   added to the active module list and loaded; i.e., their database schema
+   *   is not installed. hook_install() is not invoked. A custom module weight
+   *   is not applied.
+   *
+   * @throws \LogicException
+   *   If any module in $modules is already enabled.
+   * @throws \RuntimeException
+   *   If a module is not enabled after enabling it.
+   */
+  protected function enableModules(array $modules) {
+    $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
+    if ($trace[1]['function'] === 'setUp') {
+      trigger_error('KernelTestBase::enableModules() should not be called from setUp(). Use the $modules property instead.', E_USER_DEPRECATED);
+    }
+    unset($trace);
+
+    // Perform an ExtensionDiscovery scan as this function may receive a
+    // profile that is not the current profile, and we don't yet have a cached
+    // way to receive inactive profile information.
+    // @todo Remove as part of https://www.drupal.org/node/2186491
+    $listing = new ExtensionDiscovery(\Drupal::root());
+    $module_list = $listing->scan('module');
+    // In ModuleHandlerTest we pass in a profile as if it were a module.
+    $module_list += $listing->scan('profile');
+
+    // Set the list of modules in the extension handler.
+    $module_handler = $this->container->get('module_handler');
+
+    // Write directly to active storage to avoid early instantiation of
+    // the event dispatcher which can prevent modules from registering events.
+    $active_storage = $this->container->get('config.storage');
+    $extension_config = $active_storage->read('core.extension');
+
+    foreach ($modules as $module) {
+      if ($module_handler->moduleExists($module)) {
+        continue;
+      }
+      $module_handler->addModule($module, $module_list[$module]->getPath());
+      // Maintain the list of enabled modules in configuration.
+      $extension_config['module'][$module] = 0;
+    }
+    $active_storage->write('core.extension', $extension_config);
+
+    // Update the kernel to make their services available.
+    $extensions = $module_handler->getModuleList();
+    $this->container->get('kernel')->updateModules($extensions, $extensions);
+
+    // Ensure isLoaded() is TRUE in order to make
+    // \Drupal\Core\Theme\ThemeManagerInterface::render() work.
+    // Note that the kernel has rebuilt the container; this $module_handler is
+    // no longer the $module_handler instance from above.
+    $module_handler = $this->container->get('module_handler');
+    $module_handler->reload();
+    foreach ($modules as $module) {
+      if (!$module_handler->moduleExists($module)) {
+        throw new \RuntimeException("$module module is not enabled after enabling it.");
+      }
+    }
+  }
+
+  /**
+   * Disables modules for this test.
+   *
+   * @param string[] $modules
+   *   A list of modules to disable. Dependencies are not resolved; i.e.,
+   *   multiple modules have to be specified with dependent modules first.
+   *   Code of previously enabled modules is still loaded. The modules are only
+   *   removed from the active module list.
+   *
+   * @throws \LogicException
+   *   If any module in $modules is already disabled.
+   * @throws \RuntimeException
+   *   If a module is not disabled after disabling it.
+   */
+  protected function disableModules(array $modules) {
+    // Unset the list of modules in the extension handler.
+    $module_handler = $this->container->get('module_handler');
+    $module_filenames = $module_handler->getModuleList();
+    $extension_config = $this->config('core.extension');
+    foreach ($modules as $module) {
+      if (!$module_handler->moduleExists($module)) {
+        throw new \LogicException("$module module cannot be disabled because it is not enabled.");
+      }
+      unset($module_filenames[$module]);
+      $extension_config->clear('module.' . $module);
+    }
+    $extension_config->save();
+    $module_handler->setModuleList($module_filenames);
+    $module_handler->resetImplementations();
+    // Update the kernel to remove their services.
+    $this->container->get('kernel')->updateModules($module_filenames, $module_filenames);
+
+    // Ensure isLoaded() is TRUE in order to make
+    // \Drupal\Core\Theme\ThemeManagerInterface::render() work.
+    // Note that the kernel has rebuilt the container; this $module_handler is
+    // no longer the $module_handler instance from above.
+    $module_handler = $this->container->get('module_handler');
+    $module_handler->reload();
+    foreach ($modules as $module) {
+      if ($module_handler->moduleExists($module)) {
+        throw new \RuntimeException("$module module is not disabled after disabling it.");
+      }
+    }
+  }
+
+  /**
+   * Renders a render array.
+   *
+   * @param array $elements
+   *   The elements to render.
+   *
+   * @return string
+   *   The rendered string output (typically HTML).
+   */
+  protected function render(array &$elements) {
+    // \Drupal\Core\Render\BareHtmlPageRenderer::renderBarePage calls out to
+    // system_page_attachments() directly.
+    if (!\Drupal::moduleHandler()->moduleExists('system')) {
+      throw new \Exception(__METHOD__ . ' requires system module to be installed.');
+    }
+
+    // Use the bare HTML page renderer to render our links.
+    $renderer = $this->container->get('bare_html_page_renderer');
+    $response = $renderer->renderBarePage($elements, '', 'maintenance_page');
+
+    // Glean the content from the response object.
+    $content = $response->getContent();
+    $this->setRawContent($content);
+    $this->verbose('<pre style="white-space: pre-wrap">' . Html::escape($content));
+    return $content;
+  }
+
+  /**
+   * Sets an in-memory Settings variable.
+   *
+   * @param string $name
+   *   The name of the setting to set.
+   * @param bool|string|int|array|null $value
+   *   The value to set. Note that array values are replaced entirely; use
+   *   \Drupal\Core\Site\Settings::get() to perform custom merges.
+   */
+  protected function setSetting($name, $value) {
+    $settings = Settings::getInstance() ? Settings::getAll() : [];
+    $settings[$name] = $value;
+    new Settings($settings);
+  }
+
+  /**
+   * Stops test execution.
+   */
+  protected function stop() {
+    $this->getTestResultObject()->stop();
+  }
+
+  /**
+   * Dumps the current state of the virtual filesystem to STDOUT.
+   */
+  protected function vfsDump() {
+    vfsStream::inspect(new vfsStreamPrintVisitor());
+  }
+
+  /**
+   * Returns the modules to enable for this test.
+   *
+   * @param string $class
+   *   The fully-qualified class name of this test.
+   *
+   * @return array
+   */
+  private static function getModulesToEnable($class) {
+    $modules = [];
+    while ($class) {
+      if (property_exists($class, 'modules')) {
+        // Only add the modules, if the $modules property was not inherited.
+        $rp = new \ReflectionProperty($class, 'modules');
+        if ($rp->class == $class) {
+          $modules[$class] = $class::$modules;
+        }
+      }
+      $class = get_parent_class($class);
+    }
+    // Modules have been collected in reverse class hierarchy order; modules
+    // defined by base classes should be sorted first. Then, merge the results
+    // together.
+    $modules = array_reverse($modules);
+    return call_user_func_array('array_merge_recursive', $modules);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function prepareTemplate(\Text_Template $template) {
+    $bootstrap_globals = '';
+
+    // Fix missing bootstrap.php when $preserveGlobalState is FALSE.
+    // @see https://github.com/sebastianbergmann/phpunit/pull/797
+    $bootstrap_globals .= '$__PHPUNIT_BOOTSTRAP = ' . var_export($GLOBALS['__PHPUNIT_BOOTSTRAP'], TRUE) . ";\n";
+
+    // Avoid repetitive test namespace discoveries to improve performance.
+    // @see /core/tests/bootstrap.php
+    $bootstrap_globals .= '$namespaces = ' . var_export($GLOBALS['namespaces'], TRUE) . ";\n";
+
+    $template->setVar([
+      'constants' => '',
+      'included_files' => '',
+      'globals' => $bootstrap_globals,
+    ]);
+  }
+
+  /**
+   * Returns whether the current test method is running in a separate process.
+   *
+   * Note that KernelTestBase will run in a separate process by default.
+   *
+   * @return bool
+   *
+   * @see \Drupal\KernelTests\KernelTestBase::$runTestInSeparateProcess
+   * @see https://github.com/sebastianbergmann/phpunit/pull/1350
+   *
+   * @deprecated in Drupal 8.4.x, for removal before the Drupal 9.0.0 release.
+   *   KernelTestBase tests are always run in isolated processes.
+   */
+  protected function isTestInIsolation() {
+    @trigger_error(__CLASS__ . '::' . __FUNCTION__ . '() is deprecated in Drupal 8.4.x, for removal before the Drupal 9.0.0 release. KernelTestBase tests are always run in isolated processes.', E_USER_DEPRECATED);
+    return function_exists('__phpunit_run_isolated_test');
+  }
+
+  /**
+   * BC: Automatically resolve former KernelTestBase class properties.
+   *
+   * Test authors should follow the provided instructions and adjust their tests
+   * accordingly.
+   *
+   * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
+   */
+  public function __get($name) {
+    if (in_array($name, [
+      'public_files_directory',
+      'private_files_directory',
+      'temp_files_directory',
+      'translation_files_directory',
+    ])) {
+      // @comment it in again.
+      trigger_error(sprintf("KernelTestBase::\$%s no longer exists. Use the regular API method to retrieve it instead (e.g., Settings).", $name), E_USER_DEPRECATED);
+      switch ($name) {
+        case 'public_files_directory':
+          return Settings::get('file_public_path', \Drupal::service('site.path') . '/files');
+
+        case 'private_files_directory':
+          return Settings::get('file_private_path');
+
+        case 'temp_files_directory':
+          return file_directory_temp();
+
+        case 'translation_files_directory':
+          return Settings::get('file_public_path', \Drupal::service('site.path') . '/translations');
+      }
+    }
+
+    if ($name === 'configDirectories') {
+      trigger_error(sprintf("KernelTestBase::\$%s no longer exists. Use config_get_config_directory() directly instead.", $name), E_USER_DEPRECATED);
+      return [
+        CONFIG_SYNC_DIRECTORY => config_get_config_directory(CONFIG_SYNC_DIRECTORY),
+      ];
+    }
+
+    $denied = [
+      // @see \Drupal\simpletest\TestBase
+      'testId',
+      'timeLimit',
+      'results',
+      'assertions',
+      'skipClasses',
+      'verbose',
+      'verboseId',
+      'verboseClassName',
+      'verboseDirectory',
+      'verboseDirectoryUrl',
+      'dieOnFail',
+      'kernel',
+      // @see \Drupal\simpletest\TestBase::prepareEnvironment()
+      'generatedTestFiles',
+      // Properties from the old KernelTestBase class that has been removed.
+      'keyValueFactory',
+    ];
+    if (in_array($name, $denied) || strpos($name, 'original') === 0) {
+      throw new \RuntimeException(sprintf('TestBase::$%s property no longer exists', $name));
+    }
+  }
+
+  /**
+   * Prevents serializing any properties.
+   *
+   * Kernel tests are run in a separate process. To do this PHPUnit creates a
+   * script to run the test. If it fails, the test result object will contain a
+   * stack trace which includes the test object. It will attempt to serialize
+   * it. Returning an empty array prevents it from serializing anything it
+   * should not.
+   *
+   * @return array
+   *   An empty array.
+   *
+   * @see vendor/phpunit/phpunit/src/Util/PHP/Template/TestCaseMethod.tpl.dist
+   */
+  public function __sleep() {
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function assertEquals($expected, $actual, $message = '', $delta = 0.0, $maxDepth = 10, $canonicalize = FALSE, $ignoreCase = FALSE) {
+    // Cast objects implementing MarkupInterface to string instead of
+    // relying on PHP casting them to string depending on what they are being
+    // comparing with.
+    $expected = static::castSafeStrings($expected);
+    $actual = static::castSafeStrings($actual);
+    parent::assertEquals($expected, $actual, $message, $delta, $maxDepth, $canonicalize, $ignoreCase);
+  }
+
+}