diff --git a/core/modules/editor/src/Tests/QuickEditIntegrationTest.php b/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
similarity index 98%
rename from core/modules/editor/src/Tests/QuickEditIntegrationTest.php
rename to core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
index 1b4798b..5106729 100644
--- a/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
+++ b/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\editor\Tests\QuickEditIntegrationTest.
+ * Contains \Drupal\Tests\editor\Kernel\QuickEditIntegrationTest.
  */
 
-namespace Drupal\editor\Tests;
+namespace Drupal\Tests\editor\Kernel;
 
 use Drupal\Component\Serialization\Json;
 use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
@@ -13,7 +13,7 @@
 use Drupal\editor\Entity\Editor;
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\quickedit\MetadataGenerator;
-use Drupal\quickedit\Tests\QuickEditTestBase;
+use Drupal\Tests\quickedit\Kernel\QuickEditTestBase;
 use Drupal\quickedit_test\MockEditEntityFieldAccessCheck;
 use Drupal\editor\EditorController;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/core/modules/forum/src/Tests/ForumValidationTest.php b/core/modules/forum/tests/src/Kernel/ForumValidationTest.php
similarity index 88%
rename from core/modules/forum/src/Tests/ForumValidationTest.php
rename to core/modules/forum/tests/src/Kernel/ForumValidationTest.php
index c215c8e..3b66d3e 100644
--- a/core/modules/forum/src/Tests/ForumValidationTest.php
+++ b/core/modules/forum/tests/src/Kernel/ForumValidationTest.php
@@ -2,21 +2,21 @@
 
 /**
  * @file
- * Contains \Drupal\forum\Tests\ForumValidationTest.
+ * Contains \Drupal\Tests\forum\Kernel\ForumValidationTest.
  */
 
-namespace Drupal\forum\Tests;
+namespace Drupal\Tests\forum\Kernel;
 
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\taxonomy\Entity\Term;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests forum validation constraints.
  *
  * @group forum
  */
-class ForumValidationTest extends EntityUnitTestBase {
+class ForumValidationTest extends EntityKernelTestBase {
 
   /**
    * Modules to install.
diff --git a/core/modules/language/src/Tests/Condition/LanguageConditionTest.php b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
similarity index 95%
rename from core/modules/language/src/Tests/Condition/LanguageConditionTest.php
rename to core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
index e976ae0..713820b 100644
--- a/core/modules/language/src/Tests/Condition/LanguageConditionTest.php
+++ b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\Condition\LanguageConditionTest.
+ * Contains \Drupal\Tests\language\Kernel\Condition\LanguageConditionTest.
  */
 
-namespace Drupal\language\Tests\Condition;
+namespace Drupal\Tests\language\Kernel\Condition;
 
 use Drupal\language\Entity\ConfigurableLanguage;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests that the language condition, provided by the language module, is
diff --git a/core/modules/language/src/Tests/ConfigurableLanguageTest.php b/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
similarity index 85%
rename from core/modules/language/src/Tests/ConfigurableLanguageTest.php
rename to core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
index c1d8889..832e9da 100644
--- a/core/modules/language/src/Tests/ConfigurableLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
@@ -1,12 +1,12 @@
 <?php
 /**
  * @file
- * Contains \Drupal\language\Tests\ConfigurableLanguageTest.
+ * Contains \Drupal\Tests\language\Kernel\ConfigurableLanguageTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\language\Entity\ConfigurableLanguage;
 
 /**
diff --git a/core/modules/language/src/Tests/EntityDefaultLanguageTest.php b/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
similarity index 96%
rename from core/modules/language/src/Tests/EntityDefaultLanguageTest.php
rename to core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
index 5972374..1f82ea6 100644
--- a/core/modules/language/src/Tests/EntityDefaultLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\EntityDefaultLanguageTest.
+ * Contains \Drupal\Tests\language\Kernel\EntityDefaultLanguageTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\language\Entity\ContentLanguageSettings;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests default language code is properly generated for entities.
@@ -23,7 +23,7 @@ class EntityDefaultLanguageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = array('language', 'node', 'field', 'text', 'user');
+  public static $modules = array('language', 'node', 'field', 'text', 'user', 'system');
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/src/Tests/EntityUrlLanguageTest.php b/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
similarity index 97%
rename from core/modules/language/src/Tests/EntityUrlLanguageTest.php
rename to core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
index 5d0872e..2ea0054 100644
--- a/core/modules/language/src/Tests/EntityUrlLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\EntityUrlLanguageTest.
+ * Contains \Drupal\Tests\language\Kernel\EntityUrlLanguageTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\entity_test\Entity\EntityTest;
@@ -51,7 +51,8 @@ protected function setUp() {
     $config = $this->config('language.negotiation');
     $config->set('url.prefixes', ['en' => 'en', 'es' => 'es', 'fr' => 'fr'])
       ->save();
-    $this->kernel->rebuildContainer();
+
+    \Drupal::service('kernel')->rebuildContainer();
 
     $this->createTranslatableEntity();
   }
diff --git a/core/modules/language/src/Tests/LanguageConfigOverrideInstallTest.php b/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
similarity index 88%
rename from core/modules/language/src/Tests/LanguageConfigOverrideInstallTest.php
rename to core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
index b3cdd09..23b7440 100644
--- a/core/modules/language/src/Tests/LanguageConfigOverrideInstallTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\LanguageConfigOverrideInstallTest.
+ * Contains \Drupal\Tests\language\Kernel\LanguageConfigOverrideInstallTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
 use Drupal\language\Entity\ConfigurableLanguage;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Ensures the language config overrides can be installed.
diff --git a/core/modules/language/src/Tests/LanguageDependencyInjectionTest.php b/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
similarity index 95%
rename from core/modules/language/src/Tests/LanguageDependencyInjectionTest.php
rename to core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
index fc13a61..755eb51 100644
--- a/core/modules/language/src/Tests/LanguageDependencyInjectionTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageDependencyInjectionTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\LanguageDependencyInjectionTest.
+ * Contains \Drupal\Tests\language\Kernel\LanguageDependencyInjectionTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
 use Drupal\language\Entity\ConfigurableLanguage;
 use Drupal\language\Exception\DeleteDefaultLanguageException;
diff --git a/core/modules/language/src/Tests/LanguageFallbackTest.php b/core/modules/language/tests/src/Kernel/LanguageFallbackTest.php
similarity index 96%
rename from core/modules/language/src/Tests/LanguageFallbackTest.php
rename to core/modules/language/tests/src/Kernel/LanguageFallbackTest.php
index c57df3d..3854f59 100644
--- a/core/modules/language/src/Tests/LanguageFallbackTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageFallbackTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\LanguageFallbackTest.
+ * Contains \Drupal\Tests\language\Kernel\LanguageFallbackTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\language\Entity\ConfigurableLanguage;
diff --git a/core/modules/language/src/Tests/LanguageTestBase.php b/core/modules/language/tests/src/Kernel/LanguageTestBase.php
similarity index 85%
rename from core/modules/language/src/Tests/LanguageTestBase.php
rename to core/modules/language/tests/src/Kernel/LanguageTestBase.php
index f06f203..47d08a3 100644
--- a/core/modules/language/src/Tests/LanguageTestBase.php
+++ b/core/modules/language/tests/src/Kernel/LanguageTestBase.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\LanguageTestBase.
+ * Contains \Drupal\Tests\language\Kernel\LanguageTestBase.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Test for dependency injected language object.
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 74b76ec..aecad6c 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -1042,7 +1042,7 @@ function locale_string_is_safe($string) {
   // inject javascript. When \Drupal\Component\Utility\Xss::filter() removes
   // part of tokens, it causes the string to not be translatable when it should
   // be translatable.
-  // @see \Drupal\locale\Tests\LocaleStringIsSafeTest::testLocaleStringIsSafe()
+  // @see \Drupal\Tests\locale\Kernel\LocaleStringIsSafeTest::testLocaleStringIsSafe()
   //
   // We can recognize tokens since they are wrapped with brackets and are only
   // composed of alphanumeric characters, colon, underscore, and dashes. We can
diff --git a/core/modules/locale/tests/modules/locale_test/config/schema/locale_test.schema.yml b/core/modules/locale/tests/modules/locale_test/config/schema/locale_test.schema.yml
index f6cf7b9..958ce1b 100644
--- a/core/modules/locale/tests/modules/locale_test/config/schema/locale_test.schema.yml
+++ b/core/modules/locale/tests/modules/locale_test/config/schema/locale_test.schema.yml
@@ -7,7 +7,7 @@ locale_test.no_translation:
     test:
       type: string
       label: 'Test'
-      # See \Drupal\locale\Tests\LocaleConfigSubscriberTest
+      # See \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest
       translatable: true
 
 locale_test.translation:
@@ -17,5 +17,5 @@ locale_test.translation:
     test:
       type: string
       label: 'Test'
-      # See \Drupal\locale\Tests\LocaleConfigSubscriberTest
+      # See \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest
       translatable: true
diff --git a/core/modules/locale/src/Tests/LocaleConfigManagerTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
similarity index 97%
rename from core/modules/locale/src/Tests/LocaleConfigManagerTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
index 193f4fa..fd1c07d 100644
--- a/core/modules/locale/src/Tests/LocaleConfigManagerTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleConfigManagerTest.
+ * Contains \Drupal\Tests\locale\Kernel\LocaleConfigManagerTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Kernel;
 
 use Drupal\block\Entity\Block;
 use Drupal\language\Entity\ConfigurableLanguage;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests that the locale config manager operates correctly.
diff --git a/core/modules/locale/src/Tests/LocaleConfigSubscriberForeignTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberForeignTest.php
similarity index 99%
rename from core/modules/locale/src/Tests/LocaleConfigSubscriberForeignTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberForeignTest.php
index 00018f1..3179d8e 100644
--- a/core/modules/locale/src/Tests/LocaleConfigSubscriberForeignTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberForeignTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Language\Language;
 use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest;
 
 /**
  * Tests default configuration handling with a foreign default language.
diff --git a/core/modules/locale/src/Tests/LocaleConfigSubscriberTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
similarity index 98%
rename from core/modules/locale/src/Tests/LocaleConfigSubscriberTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
index 38e8ad0..01bba94 100644
--- a/core/modules/locale/src/Tests/LocaleConfigSubscriberTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
@@ -2,16 +2,16 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleConfigSubscriberTest.
+ * Contains \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Kernel;
 
 use Drupal\language\Entity\ConfigurableLanguage;
 use Drupal\locale\Locale;
 use Drupal\locale\StringInterface;
 use Drupal\locale\TranslationString;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests that shipped configuration translations are updated correctly.
@@ -23,7 +23,7 @@ class LocaleConfigSubscriberTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'locale', 'system'];
+  public static $modules = ['language', 'locale', 'system', 'locale_test'];
 
   /**
    * The configurable language manager used in this test.
@@ -65,7 +65,6 @@ protected function setUp() {
 
     $this->setupLanguages();
 
-    $this->enableModules(['locale_test']);
     $this->installConfig(['locale_test']);
     // Simulate this hook invoked which would happen if in a non-kernel test
     // or normal environment.
diff --git a/core/modules/locale/src/Tests/LocaleConfigurableLanguageManagerTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
similarity index 91%
rename from core/modules/locale/src/Tests/LocaleConfigurableLanguageManagerTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
index 6bdbc43..f047953 100644
--- a/core/modules/locale/src/Tests/LocaleConfigurableLanguageManagerTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleConfigurableLanguageManagerTest.
+ * Contains \Drupal\Tests\locale\Kernel\LocaleConfigurableLanguageManagerTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\language\Entity\ConfigurableLanguage;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 
 /**
diff --git a/core/modules/locale/src/Tests/LocaleStringIsSafeTest.php b/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
similarity index 96%
rename from core/modules/locale/src/Tests/LocaleStringIsSafeTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
index 603187f..c50ae6b 100644
--- a/core/modules/locale/src/Tests/LocaleStringIsSafeTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleStringIsSafeTest.
+ * Contains \Drupal\Tests\locale\Kernel\LocaleStringIsSafeTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests locale translation safe string handling.
diff --git a/core/modules/locale/src/Tests/LocaleTranslationProjectsTest.php b/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
similarity index 87%
rename from core/modules/locale/src/Tests/LocaleTranslationProjectsTest.php
rename to core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
index 79b7f1f..08de6d9 100644
--- a/core/modules/locale/src/Tests/LocaleTranslationProjectsTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleTranslationProjectsTest.
+ * Contains \Drupal\Tests\locale\Kernel\LocaleTranslationProjectsTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests locale translation project handling.
@@ -19,7 +19,7 @@ class LocaleTranslationProjectsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['locale', 'locale_test'];
+  public static $modules = ['locale', 'locale_test', 'system'];
 
   /**
    * The module handler used in this test.
diff --git a/core/modules/menu_link_content/src/Tests/MenuLinkContentCacheabilityBubblingTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
similarity index 96%
rename from core/modules/menu_link_content/src/Tests/MenuLinkContentCacheabilityBubblingTest.php
rename to core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
index 9e1dbf1..38b7ac5 100644
--- a/core/modules/menu_link_content/src/Tests/MenuLinkContentCacheabilityBubblingTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
@@ -2,17 +2,17 @@
 
 /**
  * @file
- * Contains \Drupal\menu_link_content\Tests\MenuLinkContentCacheabilityBubblingTest.
+ * Contains \Drupal\Tests\menu_link_content\Kernel\MenuLinkContentCacheabilityBubblingTest.
  */
 
-namespace Drupal\menu_link_content\Tests;
+namespace Drupal\Tests\menu_link_content\Kernel;
 
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Menu\MenuTreeParameters;
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\menu_link_content\Entity\MenuLinkContent;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\User;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/core/modules/menu_link_content/src/Tests/MenuLinkContentDeriverTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
similarity index 95%
rename from core/modules/menu_link_content/src/Tests/MenuLinkContentDeriverTest.php
rename to core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
index defbaad..7dd3bc3 100644
--- a/core/modules/menu_link_content/src/Tests/MenuLinkContentDeriverTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
@@ -2,15 +2,15 @@
 
 /**
  * @file
- * Contains \Drupal\menu_link_content\Tests\MenuLinkContentDeriverTest.
+ * Contains \Drupal\Tests\menu_link_content\Kernel\MenuLinkContentDeriverTest.
  */
 
-namespace Drupal\menu_link_content\Tests;
+namespace Drupal\Tests\menu_link_content\Kernel;
 
 use Drupal\Core\Menu\MenuTreeParameters;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 use Drupal\menu_link_content\Entity\MenuLinkContent;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Symfony\Component\Routing\Route;
 
 /**
diff --git a/core/modules/menu_link_content/src/Tests/PathAliasMenuLinkContentTest.php b/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
similarity index 91%
rename from core/modules/menu_link_content/src/Tests/PathAliasMenuLinkContentTest.php
rename to core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
index 7be92e1..c904225 100644
--- a/core/modules/menu_link_content/src/Tests/PathAliasMenuLinkContentTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
@@ -2,16 +2,16 @@
 
 /**
  * @file
- * Contains \Drupal\menu_link_content\Tests\PathAliasMenuLinkContentTest.
+ * Contains \Drupal\Tests\menu_link_content\Kernel\PathAliasMenuLinkContentTest.
  */
 
-namespace Drupal\menu_link_content\Tests;
+namespace Drupal\Tests\menu_link_content\Kernel;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Menu\MenuTreeParameters;
 use Drupal\menu_link_content\Entity\MenuLinkContent;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Ensures that the menu tree adapts to path alias changes.
@@ -41,8 +41,8 @@ protected function setUp() {
   /**
    * {@inheritdoc}
    */
-  public function containerBuild(ContainerBuilder $container) {
-    parent::containerBuild($container);
+  public function register(ContainerBuilder $container) {
+    parent::register($container);
 
     $definition = $container->getDefinition('path_processor_alias');
     $definition
diff --git a/core/modules/node/src/Tests/Config/NodeImportChangeTest.php b/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
similarity index 91%
rename from core/modules/node/src/Tests/Config/NodeImportChangeTest.php
rename to core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
index 327173c..e4dc638 100644
--- a/core/modules/node/src/Tests/Config/NodeImportChangeTest.php
+++ b/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\Config\NodeImportChangeTest.
+ * Contains \Drupal\Tests\node\Kernel\Config\NodeImportChangeTest.
  */
 
-namespace Drupal\node\Tests\Config;
+namespace Drupal\Tests\node\Kernel\Config;
 
 use Drupal\node\Entity\NodeType;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Change content types during config create method invocation.
diff --git a/core/modules/node/src/Tests/Config/NodeImportCreateTest.php b/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
similarity index 88%
rename from core/modules/node/src/Tests/Config/NodeImportCreateTest.php
rename to core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
index fc87cf3..44d40a0 100644
--- a/core/modules/node/src/Tests/Config/NodeImportCreateTest.php
+++ b/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\Config\NodeImportCreateTest.
+ * Contains \Drupal\Tests\node\Kernel\Config\NodeImportCreateTest.
  */
 
-namespace Drupal\node\Tests\Config;
+namespace Drupal\Tests\node\Kernel\Config;
 
 use Drupal\field\Entity\FieldConfig;
 use Drupal\node\Entity\NodeType;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Create content types during config create method invocation.
@@ -64,8 +64,8 @@ public function testImportCreate() {
     $sync = $this->container->get('config.storage.sync');
     $this->copyConfig($active, $sync);
     // Manually add new node type.
-    $src_dir = drupal_get_path('module', 'node_test_config') . '/sync';
-    $target_dir = $this->configDirectories[CONFIG_SYNC_DIRECTORY];
+    $src_dir = __DIR__ . '/../../../modules/node_test_config/sync';
+    $target_dir = config_get_config_directory(CONFIG_SYNC_DIRECTORY);
     $this->assertTrue(file_unmanaged_copy("$src_dir/$node_type_config_name.yml", "$target_dir/$node_type_config_name.yml"));
 
     // Import the content of the sync directory.
diff --git a/core/modules/node/src/Tests/NodeBodyFieldStorageTest.php b/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
similarity index 93%
rename from core/modules/node/src/Tests/NodeBodyFieldStorageTest.php
rename to core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
index 2441a57..562a5a1 100644
--- a/core/modules/node/src/Tests/NodeBodyFieldStorageTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
@@ -2,15 +2,15 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeBodyFieldStorageTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeBodyFieldStorageTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\node\Entity\NodeType;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests node body field storage.
diff --git a/core/modules/node/src/Tests/Condition/NodeConditionTest.php b/core/modules/node/tests/src/Kernel/NodeConditionTest.php
similarity index 94%
rename from core/modules/node/src/Tests/Condition/NodeConditionTest.php
rename to core/modules/node/tests/src/Kernel/NodeConditionTest.php
index 6af1d77..a365927 100644
--- a/core/modules/node/src/Tests/Condition/NodeConditionTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeConditionTest.php
@@ -2,21 +2,21 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\Condition\NodeConditionTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeConditionTest.
  */
 
-namespace Drupal\node\Tests\Condition;
+namespace Drupal\Tests\node\Kernel;
 
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests that conditions, provided by the node module, are working properly.
  *
  * @group node
  */
-class NodeConditionTest extends EntityUnitTestBase {
+class NodeConditionTest extends EntityKernelTestBase {
 
   public static $modules = array('node');
 
diff --git a/core/modules/node/src/Tests/NodeFieldAccessTest.php b/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
similarity index 96%
rename from core/modules/node/src/Tests/NodeFieldAccessTest.php
rename to core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
index 2b18e15..62b7e93 100644
--- a/core/modules/node/src/Tests/NodeFieldAccessTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
@@ -1,22 +1,22 @@
 <?php
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeFieldAccessTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeFieldAccessTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
 use Drupal\Component\Utility\SafeMarkup;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests node field level access.
  *
  * @group node
  */
-class NodeFieldAccessTest extends EntityUnitTestBase {
+class NodeFieldAccessTest extends EntityKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/node/src/Tests/NodeFieldOverridesTest.php b/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
similarity index 87%
rename from core/modules/node/src/Tests/NodeFieldOverridesTest.php
rename to core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
index 2472abe..3bff25c 100644
--- a/core/modules/node/src/Tests/NodeFieldOverridesTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
@@ -2,22 +2,22 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeFieldOverridesTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeFieldOverridesTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
 use Drupal\Core\Field\Entity\BaseFieldOverride;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests node field overrides.
  *
  * @group node
  */
-class NodeFieldOverridesTest extends EntityUnitTestBase {
+class NodeFieldOverridesTest extends EntityKernelTestBase {
 
   /**
    * Current logged in user.
diff --git a/core/modules/node/src/Tests/NodeListBuilderTest.php b/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
similarity index 87%
rename from core/modules/node/src/Tests/NodeListBuilderTest.php
rename to core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
index 2d23604..53bc93e 100644
--- a/core/modules/node/src/Tests/NodeListBuilderTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeListBuilderTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeListBuilderTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests the admin listing fallback when views is not enabled.
diff --git a/core/modules/node/src/Tests/NodeOwnerTest.php b/core/modules/node/tests/src/Kernel/NodeOwnerTest.php
similarity index 90%
rename from core/modules/node/src/Tests/NodeOwnerTest.php
rename to core/modules/node/tests/src/Kernel/NodeOwnerTest.php
index 48ec33d..6f3316c 100644
--- a/core/modules/node/src/Tests/NodeOwnerTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeOwnerTest.php
@@ -2,22 +2,22 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeOwnerTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeOwnerTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\language\Entity\ConfigurableLanguage;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests node owner functionality.
  *
  * @group Entity
  */
-class NodeOwnerTest extends EntityUnitTestBase {
+class NodeOwnerTest extends EntityKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/node/src/Tests/NodeTokenReplaceTest.php b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
similarity index 95%
rename from core/modules/node/src/Tests/NodeTokenReplaceTest.php
rename to core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
index 9050de9..e4a94b4 100644
--- a/core/modules/node/src/Tests/NodeTokenReplaceTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
@@ -2,17 +2,17 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeTokenReplaceTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeTokenReplaceTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
 use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Html;
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\System\TokenReplaceUnitTestBase;
+use Drupal\Tests\system\Kernel\Token\TokenReplaceKernelTestBase;
 
 /**
  * Generates text using placeholders for dummy content to check node token
@@ -20,7 +20,7 @@
  *
  * @group node
  */
-class NodeTokenReplaceTest extends TokenReplaceUnitTestBase {
+class NodeTokenReplaceTest extends TokenReplaceKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/node/src/Tests/NodeValidationTest.php b/core/modules/node/tests/src/Kernel/NodeValidationTest.php
similarity index 92%
rename from core/modules/node/src/Tests/NodeValidationTest.php
rename to core/modules/node/tests/src/Kernel/NodeValidationTest.php
index c6e26cc..0f487c3 100644
--- a/core/modules/node/src/Tests/NodeValidationTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeValidationTest.php
@@ -2,21 +2,21 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\NodeValidationTest.
+ * Contains \Drupal\Tests\node\Kernel\NodeValidationTest.
  */
 
-namespace Drupal\node\Tests;
+namespace Drupal\Tests\node\Kernel;
 
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 
 /**
  * Tests node validation constraints.
  *
  * @group node
  */
-class NodeValidationTest extends EntityUnitTestBase {
+class NodeValidationTest extends EntityKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/quickedit/src/Tests/EditorSelectionTest.php b/core/modules/quickedit/tests/src/Kernel/EditorSelectionTest.php
similarity index 98%
rename from core/modules/quickedit/src/Tests/EditorSelectionTest.php
rename to core/modules/quickedit/tests/src/Kernel/EditorSelectionTest.php
index dfc73f0..86405af 100644
--- a/core/modules/quickedit/src/Tests/EditorSelectionTest.php
+++ b/core/modules/quickedit/tests/src/Kernel/EditorSelectionTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\quickedit\Tests\EditorSelectionTest.
+ * Contains \Drupal\Tests\quickedit\Kernel\EditorSelectionTest.
  */
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\quickedit\EditorSelector;
diff --git a/core/modules/quickedit/src/Tests/MetadataGeneratorTest.php b/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
similarity index 97%
rename from core/modules/quickedit/src/Tests/MetadataGeneratorTest.php
rename to core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
index f4633e1..d7348cd 100644
--- a/core/modules/quickedit/src/Tests/MetadataGeneratorTest.php
+++ b/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
@@ -2,16 +2,17 @@
 
 /**
  * @file
- * Contains \Drupal\quickedit\Tests\MetadataGeneratorTest.
+ * Contains \Drupal\Tests\quickedit\Kernel\MetadataGeneratorTest.
  */
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\entity_test\Entity\EntityTest;
 use Drupal\quickedit\EditorSelector;
 use Drupal\quickedit\MetadataGenerator;
 use Drupal\quickedit_test\MockEditEntityFieldAccessCheck;
 use Drupal\filter\Entity\FilterFormat;
+use Drupal\Tests\quickedit\Kernel\QuickEditTestBase;
 
 /**
  * Tests in-place field editing metadata.
diff --git a/core/modules/quickedit/src/Tests/QuickEditTestBase.php b/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
similarity index 95%
rename from core/modules/quickedit/src/Tests/QuickEditTestBase.php
rename to core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
index 85884ff..dc839d7 100644
--- a/core/modules/quickedit/src/Tests/QuickEditTestBase.php
+++ b/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\quickedit\Tests\QuickEditTestBase.
+ * Contains \Drupal\Tests\quickedit\Kernel\QuickEditTestBase.
  */
 
-namespace Drupal\quickedit\Tests;
+namespace Drupal\Tests\quickedit\Kernel;
 
 use Drupal\field\Entity\FieldConfig;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
diff --git a/core/modules/rdf/src/Tests/CrudTest.php b/core/modules/rdf/tests/src/Kernel/CrudTest.php
similarity index 96%
rename from core/modules/rdf/src/Tests/CrudTest.php
rename to core/modules/rdf/tests/src/Kernel/CrudTest.php
index e40f3e6..796d83e 100644
--- a/core/modules/rdf/src/Tests/CrudTest.php
+++ b/core/modules/rdf/tests/src/Kernel/CrudTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\rdf\Tests\CrudTest.
+ * Contains \Drupal\Tests\rdf\Kernel\CrudTest.
  */
 
-namespace Drupal\rdf\Tests;
+namespace Drupal\Tests\rdf\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests the RDF mapping CRUD functions.
diff --git a/core/modules/rdf/src/Tests/RdfaAttributesTest.php b/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
similarity index 96%
rename from core/modules/rdf/src/Tests/RdfaAttributesTest.php
rename to core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
index fb167c3..42f24b6 100644
--- a/core/modules/rdf/src/Tests/RdfaAttributesTest.php
+++ b/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\rdf\Tests\RdfaAttributesTest.
+ * Contains \Drupal\Tests\rdf\Kernel\RdfaAttributesTest.
  */
 
-namespace Drupal\rdf\Tests;
+namespace Drupal\Tests\rdf\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests RDFa attribute generation from RDF mapping.
diff --git a/core/modules/rest/src/Tests/RestLinkManagerTest.php b/core/modules/rest/tests/src/Kernel/RestLinkManagerTest.php
similarity index 96%
rename from core/modules/rest/src/Tests/RestLinkManagerTest.php
rename to core/modules/rest/tests/src/Kernel/RestLinkManagerTest.php
index a8acb33..4a88293 100644
--- a/core/modules/rest/src/Tests/RestLinkManagerTest.php
+++ b/core/modules/rest/tests/src/Kernel/RestLinkManagerTest.php
@@ -2,12 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\rest\Tests\RestLinkManagerTest.
+ * Contains \Drupal\Tests\rest\Kernel\RestLinkManagerTest.
  */
 
-namespace Drupal\rest\Tests;
+namespace Drupal\Tests\rest\Kernel;
+
 use Drupal\Core\Url;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests that REST type and relation link managers work as expected
diff --git a/core/modules/search/src/Tests/SearchExcerptTest.php b/core/modules/search/tests/src/Kernel/SearchExcerptTest.php
similarity index 98%
rename from core/modules/search/src/Tests/SearchExcerptTest.php
rename to core/modules/search/tests/src/Kernel/SearchExcerptTest.php
index 7998c1a..aaace98 100644
--- a/core/modules/search/src/Tests/SearchExcerptTest.php
+++ b/core/modules/search/tests/src/Kernel/SearchExcerptTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\search\Tests\SearchExcerptTest.
+ * Contains \Drupal\Tests\search\Kernel\SearchExcerptTest.
  */
 
-namespace Drupal\search\Tests;
+namespace Drupal\Tests\search\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests the search_excerpt() function.
diff --git a/core/modules/search/src/Tests/SearchMatchTest.php b/core/modules/search/tests/src/Kernel/SearchMatchTest.php
similarity index 98%
rename from core/modules/search/src/Tests/SearchMatchTest.php
rename to core/modules/search/tests/src/Kernel/SearchMatchTest.php
index 5e3d97a..27fd652 100644
--- a/core/modules/search/src/Tests/SearchMatchTest.php
+++ b/core/modules/search/tests/src/Kernel/SearchMatchTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\search\Tests\SearchMatchTest.
+ * Contains \Drupal\Tests\search\Kernel\SearchMatchTest.
  */
 
-namespace Drupal\search\Tests;
+namespace Drupal\Tests\search\Kernel;
 
 use Drupal\Core\Language\LanguageInterface;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 // The search index can contain different types of content. Typically the type
 // is 'node'. Here we test with _test_ and _test2_ as the type.
diff --git a/core/modules/serialization/src/Tests/SerializationTest.php b/core/modules/serialization/tests/src/Kernel/SerializationTest.php
similarity index 90%
rename from core/modules/serialization/src/Tests/SerializationTest.php
rename to core/modules/serialization/tests/src/Kernel/SerializationTest.php
index e8a97ec..39b642e 100644
--- a/core/modules/serialization/src/Tests/SerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/SerializationTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\SerializationTest.
+ * Contains \Drupal\Tests\serialization\Kernel\SerializationTest.
  */
 
-namespace Drupal\serialization\Tests;
+namespace Drupal\Tests\serialization\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Symfony\Component\Serializer\Exception\UnexpectedValueException;
 
 /**
diff --git a/core/modules/system/src/Tests/System/TokenReplaceUnitTestBase.php b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
similarity index 74%
rename from core/modules/system/src/Tests/System/TokenReplaceUnitTestBase.php
rename to core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
index 8a22de7..03eaa26 100644
--- a/core/modules/system/src/Tests/System/TokenReplaceUnitTestBase.php
+++ b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
@@ -2,17 +2,17 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\System\TokenReplaceUnitTestBase.
+ * Contains \Drupal\Tests\system\Kernel\Token\TokenReplaceKernelTestBase.
  */
 
-namespace Drupal\system\Tests\System;
+namespace Drupal\Tests\system\Kernel\Token;
 
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 
 /**
  * Base class for token replacement tests.
  */
-abstract class TokenReplaceUnitTestBase extends EntityUnitTestBase {
+abstract class TokenReplaceKernelTestBase extends EntityKernelTestBase {
 
   /**
    * The interface language.
diff --git a/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php b/core/modules/system/tests/src/Kernel/Token/TokenReplaceUnitTest.php
similarity index 96%
rename from core/modules/system/src/Tests/System/TokenReplaceUnitTest.php
rename to core/modules/system/tests/src/Kernel/Token/TokenReplaceUnitTest.php
index 64517b7..52d01b2 100644
--- a/core/modules/system/src/Tests/System/TokenReplaceUnitTest.php
+++ b/core/modules/system/tests/src/Kernel/Token/TokenReplaceUnitTest.php
@@ -2,15 +2,16 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\System\TokenReplaceUnitTest.
+ * Contains \Drupal\Tests\system\Tests\Token\TokenReplaceKernelTest.
  */
 
-namespace Drupal\system\Tests\System;
+namespace Drupal\Tests\system\Tests\Token;
 
 use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Render\BubbleableMetadata;
+use Drupal\Tests\system\Kernel\Token\TokenReplaceKernelTestBase;
 
 /**
  * Generates text using placeholders for dummy content to check token
@@ -18,7 +19,7 @@
  *
  * @group system
  */
-class TokenReplaceUnitTest extends TokenReplaceUnitTestBase {
+class TokenReplaceKernelTest extends TokenReplaceKernelTestBase {
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/src/Tests/TermKernelTest.php b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
similarity index 96%
rename from core/modules/taxonomy/src/Tests/TermKernelTest.php
rename to core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
index 549dcea..6e04cb8 100644
--- a/core/modules/taxonomy/src/Tests/TermKernelTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
@@ -2,13 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\taxonomy\Tests\TermKernelTest.
+ * Contains \Drupal\Tests\taxonomy\Kernel\TermKernelTest.
  */
 
-namespace Drupal\taxonomy\Tests;
+namespace Drupal\Tests\taxonomy\Kernel;
 
 use Drupal\taxonomy\Entity\Term;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\taxonomy\Tests\TaxonomyTestTrait;
 
 /**
  * Kernel tests for taxonomy term functions.
diff --git a/core/modules/taxonomy/src/Tests/TermValidationTest.php b/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
similarity index 90%
rename from core/modules/taxonomy/src/Tests/TermValidationTest.php
rename to core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
index b369737..422fdee 100644
--- a/core/modules/taxonomy/src/Tests/TermValidationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
@@ -2,19 +2,19 @@
 
 /**
  * @file
- * Contains \Drupal\taxonomy\Tests\TermValidationTest.
+ * Contains \Drupal\Tests\taxonomy\Kernel\TermValidationTest.
  */
 
-namespace Drupal\taxonomy\Tests;
+namespace Drupal\Tests\taxonomy\Kernel;
 
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 
 /**
  * Tests term validation constraints.
  *
  * @group taxonomy
  */
-class TermValidationTest extends EntityUnitTestBase {
+class TermValidationTest extends EntityKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/text/src/Tests/Formatter/TextFormatterTest.php b/core/modules/text/tests/src/Kernel/TextFormatterTest.php
similarity index 92%
rename from core/modules/text/src/Tests/Formatter/TextFormatterTest.php
rename to core/modules/text/tests/src/Kernel/TextFormatterTest.php
index 437b8b6..ad526c2 100644
--- a/core/modules/text/src/Tests/Formatter/TextFormatterTest.php
+++ b/core/modules/text/tests/src/Kernel/TextFormatterTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\text\Tests\Formatter\TextFormatterTest.
+ * Contains \Drupal\Tests\text\Kernel\TextFormatterTest.
  */
 
-namespace Drupal\text\Tests\Formatter;
+namespace Drupal\Tests\text\Kernel;
 
 use Drupal\field\Entity\FieldConfig;
 use Drupal\filter\Entity\FilterFormat;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
@@ -17,7 +17,7 @@
  *
  * @group text
  */
-class TextFormatterTest extends EntityUnitTestBase {
+class TextFormatterTest extends EntityKernelTestBase {
 
   /**
    * The entity type used in this test.
diff --git a/core/modules/text/src/Tests/TextSummaryTest.php b/core/modules/text/tests/src/Kernel/TextSummaryTest.php
similarity index 98%
rename from core/modules/text/src/Tests/TextSummaryTest.php
rename to core/modules/text/tests/src/Kernel/TextSummaryTest.php
index c5431a8..83251df 100644
--- a/core/modules/text/src/Tests/TextSummaryTest.php
+++ b/core/modules/text/tests/src/Kernel/TextSummaryTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\text\Tests\TextSummaryTest.
+ * Contains \Drupal\Tests\text\Kernel\TextSummaryTest.
  */
 
-namespace Drupal\text\Tests;
+namespace Drupal\Tests\text\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\filter\Entity\FilterFormat;
 
 /**
diff --git a/core/modules/tour/src/Tests/TourPluginTest.php b/core/modules/tour/tests/src/Kernel/TourPluginTest.php
similarity index 85%
rename from core/modules/tour/src/Tests/TourPluginTest.php
rename to core/modules/tour/tests/src/Kernel/TourPluginTest.php
index 8248a9d..298fb51 100644
--- a/core/modules/tour/src/Tests/TourPluginTest.php
+++ b/core/modules/tour/tests/src/Kernel/TourPluginTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\tour\Tests\TourPluginTest.
+ * Contains \Drupal\Tests\tour\Kernel\TourPluginTest.
  */
 
-namespace Drupal\tour\Tests;
+namespace Drupal\Tests\tour\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests the functionality of tour plugins.
diff --git a/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php b/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
similarity index 97%
rename from core/modules/user/src/Tests/Condition/UserRoleConditionTest.php
rename to core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
index ef92e11..ec7cb3f 100644
--- a/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php
+++ b/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Condition\UserRoleConditionTest.
+ * Contains \Drupal\Tests\user\Kernel\Condition\UserRoleConditionTest.
  */
 
-namespace Drupal\user\Tests\Condition;
+namespace Drupal\Tests\user\Kernel\Condition;
 
 use Drupal\Component\Utility\SafeMarkup;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\Role;
 use Drupal\user\Entity\User;
 use Drupal\user\RoleInterface;
diff --git a/core/modules/user/src/Tests/Field/UserNameFormatterTest.php b/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
similarity index 94%
rename from core/modules/user/src/Tests/Field/UserNameFormatterTest.php
rename to core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
index fab8cd9..13b786f 100644
--- a/core/modules/user/src/Tests/Field/UserNameFormatterTest.php
+++ b/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Field\UserNameFormatterTest.
+ * Contains \Drupal\Tests\user\Kernel\Field\UserNameFormatterTest.
  */
 
-namespace Drupal\user\Tests\Field;
+namespace Drupal\Tests\user\Kernel\Field;
 
 use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\User;
 
 /**
diff --git a/core/modules/user/src/Tests/TempStoreDatabaseTest.php b/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
similarity index 97%
rename from core/modules/user/src/Tests/TempStoreDatabaseTest.php
rename to core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
index 7d104df..8766b56 100644
--- a/core/modules/user/src/Tests/TempStoreDatabaseTest.php
+++ b/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\TempStoreDatabaseTest.
+ * Contains \Drupal\Tests\user\Kernel\TempStoreDatabaseTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\Core\KeyValueStore\KeyValueExpirableFactory;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\SharedTempStoreFactory;
 use Drupal\Core\Lock\DatabaseLockBackend;
 use Drupal\Core\Database\Database;
diff --git a/core/modules/user/src/Tests/UserAccountFormFieldsTest.php b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
similarity index 97%
rename from core/modules/user/src/Tests/UserAccountFormFieldsTest.php
rename to core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
index 843f036..d7b6e2b 100644
--- a/core/modules/user/src/Tests/UserAccountFormFieldsTest.php
+++ b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserAccountFormFieldsTest.
+ * Contains \Drupal\Tests\user\Kernel\UserAccountFormFieldsTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\Core\Form\FormState;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Verifies that the field order in user account forms is compatible with
diff --git a/core/modules/user/src/Tests/UserActionConfigSchemaTest.php b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
similarity index 89%
rename from core/modules/user/src/Tests/UserActionConfigSchemaTest.php
rename to core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
index 99c2df7..6813893 100644
--- a/core/modules/user/src/Tests/UserActionConfigSchemaTest.php
+++ b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserActionConfigSchemaTest.
+ * Contains \Drupal\Tests\user\Kernel\UserActionConfigSchemaTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\config\Tests\SchemaCheckTestTrait;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\Role;
 
 /**
diff --git a/core/modules/user/src/Tests/UserEntityReferenceTest.php b/core/modules/user/tests/src/Kernel/UserEntityReferenceTest.php
similarity index 90%
rename from core/modules/user/src/Tests/UserEntityReferenceTest.php
rename to core/modules/user/tests/src/Kernel/UserEntityReferenceTest.php
index 8e21255..8462e90 100644
--- a/core/modules/user/src/Tests/UserEntityReferenceTest.php
+++ b/core/modules/user/tests/src/Kernel/UserEntityReferenceTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserEntityReferenceTest.
+ * Contains \Drupal\Tests\user\Kernel\UserEntityReferenceTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\field\Tests\EntityReference\EntityReferenceTestTrait;
 use Drupal\field\Entity\FieldConfig;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\user\Entity\Role;
 
 /**
@@ -17,21 +17,21 @@
  *
  * @group user
  */
-class UserEntityReferenceTest extends EntityUnitTestBase {
+class UserEntityReferenceTest extends EntityKernelTestBase {
 
   use EntityReferenceTestTrait;
 
   /**
    * A randomly-generated role for testing purposes.
    *
-   * @var \Drupal\user\Entity\RoleInterface
+   * @var \Drupal\user\RoleInterface
    */
   protected $role1;
 
   /**
    * A randomly-generated role for testing purposes.
    *
-   * @var \Drupal\user\Entity\RoleInterface
+   * @var \Drupal\user\RoleInterface
    */
   protected $role2;
 
diff --git a/core/modules/user/src/Tests/UserEntityTest.php b/core/modules/user/tests/src/Kernel/UserEntityTest.php
similarity index 94%
rename from core/modules/user/src/Tests/UserEntityTest.php
rename to core/modules/user/tests/src/Kernel/UserEntityTest.php
index a9954f6..677bac2 100644
--- a/core/modules/user/src/Tests/UserEntityTest.php
+++ b/core/modules/user/tests/src/Kernel/UserEntityTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserEntityTest.
+ * Contains \Drupal\Tests\user\Kernel\UserEntityTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\User;
 use Drupal\user\RoleInterface;
 
diff --git a/core/modules/user/src/Tests/UserFieldsTest.php b/core/modules/user/tests/src/Kernel/UserFieldsTest.php
similarity index 90%
rename from core/modules/user/src/Tests/UserFieldsTest.php
rename to core/modules/user/tests/src/Kernel/UserFieldsTest.php
index dc3bef2c..905c585 100644
--- a/core/modules/user/src/Tests/UserFieldsTest.php
+++ b/core/modules/user/tests/src/Kernel/UserFieldsTest.php
@@ -2,13 +2,13 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserFieldsTest.
+ * Contains \Drupal\Tests\user\Kernel\UserFieldsTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\user\Entity\User;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests available user fields in twig.
diff --git a/core/modules/user/src/Tests/UserInstallTest.php b/core/modules/user/tests/src/Kernel/UserInstallTest.php
similarity index 91%
rename from core/modules/user/src/Tests/UserInstallTest.php
rename to core/modules/user/tests/src/Kernel/UserInstallTest.php
index 89c0680..a6c3d0d 100644
--- a/core/modules/user/src/Tests/UserInstallTest.php
+++ b/core/modules/user/tests/src/Kernel/UserInstallTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserInstallTest.
+ * Contains \Drupal\Tests\user\Kernel\UserInstallTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 
 /**
  * Tests user_install().
diff --git a/core/modules/user/src/Tests/UserRoleDeleteTest.php b/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
similarity index 93%
rename from core/modules/user/src/Tests/UserRoleDeleteTest.php
rename to core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
index 81396ac..a9557c1 100644
--- a/core/modules/user/src/Tests/UserRoleDeleteTest.php
+++ b/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserRoleDeleteTest.
+ * Contains \Drupal\Tests\user\Kernel\UserRoleDeleteTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\User;
 
 /**
diff --git a/core/modules/user/src/Tests/UserSaveStatusTest.php b/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
similarity index 88%
rename from core/modules/user/src/Tests/UserSaveStatusTest.php
rename to core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
index 7ce77c7..9de7394 100644
--- a/core/modules/user/src/Tests/UserSaveStatusTest.php
+++ b/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserSaveStatusTest.
+ * Contains \Drupal\Tests\user\Kernel\UserSaveStatusTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\User;
 
 /**
diff --git a/core/modules/user/src/Tests/UserValidationTest.php b/core/modules/user/tests/src/Kernel/UserValidationTest.php
similarity index 98%
rename from core/modules/user/src/Tests/UserValidationTest.php
rename to core/modules/user/tests/src/Kernel/UserValidationTest.php
index 54e0983..a8081f2 100644
--- a/core/modules/user/src/Tests/UserValidationTest.php
+++ b/core/modules/user/tests/src/Kernel/UserValidationTest.php
@@ -2,15 +2,15 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserValidationTest.
+ * Contains \Drupal\Tests\user\Kernel\UserValidationTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Kernel;
 
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Render\Element\Email;
-use Drupal\simpletest\KernelTestBase;
+use Drupal\KernelTests\KernelTestBase;
 use Drupal\user\Entity\Role;
 use Drupal\user\Entity\User;
 
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
index f8e0ea9..b9263c9 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
@@ -9,9 +9,9 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\field\Entity\FieldConfig;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
 use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
-use Drupal\system\Tests\Entity\EntityUnitTestBase;
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
@@ -19,7 +19,7 @@
  *
  * @group entity_reference
  */
-class EntityReferenceSelectionSortTest extends EntityUnitTestBase {
+class EntityReferenceSelectionSortTest extends EntityKernelTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/simpletest/src/Tests/MissingDependentModuleUnitTest.php b/core/tests/Drupal/KernelTests/MissingDependentModuleUnitTest.php
similarity index 74%
rename from core/modules/simpletest/src/Tests/MissingDependentModuleUnitTest.php
rename to core/tests/Drupal/KernelTests/MissingDependentModuleUnitTest.php
index d182728..4a63f5e 100644
--- a/core/modules/simpletest/src/Tests/MissingDependentModuleUnitTest.php
+++ b/core/tests/Drupal/KernelTests/MissingDependentModuleUnitTest.php
@@ -2,12 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\simpletest\Tests\MissingDependentModuleUnitTest.
+ * Contains \Drupal\KernelTests\MissingDependentModuleUnitTest.
  */
 
-namespace Drupal\simpletest\Tests;
-
-use Drupal\simpletest\KernelTestBase;
+namespace Drupal\KernelTests;
 
 /**
  * This test should not load since it requires a module that is not found.
