diff --git a/core/modules/action/tests/src/Menu/ActionLocalTasksTest.php b/core/modules/action/tests/src/Unit/Menu/ActionLocalTasksTest.php
similarity index 82%
rename from core/modules/action/tests/src/Menu/ActionLocalTasksTest.php
rename to core/modules/action/tests/src/Unit/Menu/ActionLocalTasksTest.php
index 29f60a1..2aa448b 100644
--- a/core/modules/action/tests/src/Menu/ActionLocalTasksTest.php
+++ b/core/modules/action/tests/src/Unit/Menu/ActionLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\action\Tests\Menu\ActionLocalTasksTest.
+ * Contains \Drupal\Tests\action\Unit\Menu\ActionLocalTasksTest.
  */
 
-namespace Drupal\action\Tests\Menu;
+namespace Drupal\Tests\action\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/aggregator/tests/src/Menu/AggregatorLocalTasksTest.php b/core/modules/aggregator/tests/src/Unit/Menu/AggregatorLocalTasksTest.php
similarity index 92%
rename from core/modules/aggregator/tests/src/Menu/AggregatorLocalTasksTest.php
rename to core/modules/aggregator/tests/src/Unit/Menu/AggregatorLocalTasksTest.php
index b319c7d..0eec6c6 100644
--- a/core/modules/aggregator/tests/src/Menu/AggregatorLocalTasksTest.php
+++ b/core/modules/aggregator/tests/src/Unit/Menu/AggregatorLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\aggregator\Tests\Menu\AggregatorLocalTasksTest.
+ * Contains \Drupal\Tests\aggregator\Unit\Menu\AggregatorLocalTasksTest.
  */
 
-namespace Drupal\aggregator\Tests\Menu;
+namespace Drupal\Tests\aggregator\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/aggregator/tests/src/Plugin/AggregatorPluginSettingsBaseTest.php b/core/modules/aggregator/tests/src/Unit/Plugin/AggregatorPluginSettingsBaseTest.php
similarity index 96%
rename from core/modules/aggregator/tests/src/Plugin/AggregatorPluginSettingsBaseTest.php
rename to core/modules/aggregator/tests/src/Unit/Plugin/AggregatorPluginSettingsBaseTest.php
index eb88867..c10d3ad 100644
--- a/core/modules/aggregator/tests/src/Plugin/AggregatorPluginSettingsBaseTest.php
+++ b/core/modules/aggregator/tests/src/Unit/Plugin/AggregatorPluginSettingsBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\aggregator\Tests\Plugin\AggregatorPluginSettingsBaseTest
+ * Contains \Drupal\Tests\aggregator\Unit\Plugin\AggregatorPluginSettingsBaseTest
  */
 
-namespace Drupal\aggregator\Tests\Plugin {
+namespace Drupal\Tests\aggregator\Unit\Plugin {
 
 use Drupal\aggregator\Form\SettingsForm;
 use Drupal\Core\Form\FormState;
diff --git a/core/modules/block/tests/src/BlockConfigEntityUnitTest.php b/core/modules/block/tests/src/Unit/BlockConfigEntityUnitTest.php
similarity index 96%
rename from core/modules/block/tests/src/BlockConfigEntityUnitTest.php
rename to core/modules/block/tests/src/Unit/BlockConfigEntityUnitTest.php
index c7937f4..bed4193 100644
--- a/core/modules/block/tests/src/BlockConfigEntityUnitTest.php
+++ b/core/modules/block/tests/src/Unit/BlockConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\BlockConfigEntityUnitTest.
+ * Contains \Drupal\Tests\block\Unit\BlockConfigEntityUnitTest.
  */
 
-namespace Drupal\block\Tests;
+namespace Drupal\Tests\block\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\Core\Plugin\Fixtures\TestConfigurablePlugin;
diff --git a/core/modules/block/tests/src/BlockFormTest.php b/core/modules/block/tests/src/Unit/BlockFormTest.php
similarity index 96%
rename from core/modules/block/tests/src/BlockFormTest.php
rename to core/modules/block/tests/src/Unit/BlockFormTest.php
index 3c40a83..0860f93 100644
--- a/core/modules/block/tests/src/BlockFormTest.php
+++ b/core/modules/block/tests/src/Unit/BlockFormTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\BlockFormTest.
+ * Contains \Drupal\Tests\block\Unit\BlockFormTest.
  */
 
-namespace Drupal\block\Tests;
+namespace Drupal\Tests\block\Unit;
 
 use Drupal\block\BlockForm;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/block/tests/src/CategoryAutocompleteTest.php b/core/modules/block/tests/src/Unit/CategoryAutocompleteTest.php
similarity index 95%
rename from core/modules/block/tests/src/CategoryAutocompleteTest.php
rename to core/modules/block/tests/src/Unit/CategoryAutocompleteTest.php
index 1818a6e..5089f76 100644
--- a/core/modules/block/tests/src/CategoryAutocompleteTest.php
+++ b/core/modules/block/tests/src/Unit/CategoryAutocompleteTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\CategoryAutocompleteTest.
+ * Contains \Drupal\Tests\block\Unit\CategoryAutocompleteTest.
  */
 
-namespace Drupal\block\Tests;
+namespace Drupal\Tests\block\Unit;
 
 use Drupal\block\Controller\CategoryAutocompleteController;
 use Drupal\Component\Utility\String;
diff --git a/core/modules/block/tests/src/Menu/BlockLocalTasksTest.php b/core/modules/block/tests/src/Unit/Menu/BlockLocalTasksTest.php
similarity index 95%
rename from core/modules/block/tests/src/Menu/BlockLocalTasksTest.php
rename to core/modules/block/tests/src/Unit/Menu/BlockLocalTasksTest.php
index 8470325..b1a84a4 100644
--- a/core/modules/block/tests/src/Menu/BlockLocalTasksTest.php
+++ b/core/modules/block/tests/src/Unit/Menu/BlockLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\Menu\BlockLocalTasksTest.
+ * Contains \Drupal\Tests\block\Unit\Menu\BlockLocalTasksTest.
  */
 
-namespace Drupal\block\Tests\Menu;
+namespace Drupal\Tests\block\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/block/tests/src/Plugin/DisplayVariant/FullPageVariantTest.php b/core/modules/block/tests/src/Unit/Plugin/DisplayVariant/FullPageVariantTest.php
similarity index 96%
rename from core/modules/block/tests/src/Plugin/DisplayVariant/FullPageVariantTest.php
rename to core/modules/block/tests/src/Unit/Plugin/DisplayVariant/FullPageVariantTest.php
index 94dbed3..1cbcfe5 100644
--- a/core/modules/block/tests/src/Plugin/DisplayVariant/FullPageVariantTest.php
+++ b/core/modules/block/tests/src/Unit/Plugin/DisplayVariant/FullPageVariantTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\Plugin\DisplayVariant\FullPageVariantTest.
+ * Contains \Drupal\Tests\block\Unit\Plugin\DisplayVariant\FullPageVariantTest.
  */
 
-namespace Drupal\block\Tests\Plugin\DisplayVariant;
+namespace Drupal\Tests\block\Unit\Plugin\DisplayVariant;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/block_content/tests/src/Menu/BlockContentLocalTasksTest.php b/core/modules/block_content/tests/src/Unit/Menu/BlockContentLocalTasksTest.php
similarity index 93%
rename from core/modules/block_content/tests/src/Menu/BlockContentLocalTasksTest.php
rename to core/modules/block_content/tests/src/Unit/Menu/BlockContentLocalTasksTest.php
index c52b32c..7f95e6b 100644
--- a/core/modules/block_content/tests/src/Menu/BlockContentLocalTasksTest.php
+++ b/core/modules/block_content/tests/src/Unit/Menu/BlockContentLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block_content\Tests\Menu\BlockContentLocalTasksTest.
+ * Contains \Drupal\Tests\block_content\Unit\Menu\BlockContentLocalTasksTest.
  */
 
-namespace Drupal\block_content\Tests\Menu;
+namespace Drupal\Tests\block_content\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/book/tests/src/BookManagerTest.php b/core/modules/book/tests/src/Unit/BookManagerTest.php
similarity index 97%
rename from core/modules/book/tests/src/BookManagerTest.php
rename to core/modules/book/tests/src/Unit/BookManagerTest.php
index 4abf063..d43a4a6 100644
--- a/core/modules/book/tests/src/BookManagerTest.php
+++ b/core/modules/book/tests/src/Unit/BookManagerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\book\Tests\BookManagerTest.
+ * Contains \Drupal\Tests\book\Unit\BookManagerTest.
  */
 
-namespace Drupal\book\Tests;
+namespace Drupal\Tests\book\Unit;
 
 use Drupal\book\BookManager;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/book/tests/src/Menu/BookLocalTasksTest.php b/core/modules/book/tests/src/Unit/Menu/BookLocalTasksTest.php
similarity index 93%
rename from core/modules/book/tests/src/Menu/BookLocalTasksTest.php
rename to core/modules/book/tests/src/Unit/Menu/BookLocalTasksTest.php
index c9102a5..2e58f85 100644
--- a/core/modules/book/tests/src/Menu/BookLocalTasksTest.php
+++ b/core/modules/book/tests/src/Unit/Menu/BookLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\book\Tests\Menu\BookLocalTasksTest.
+ * Contains \Drupal\Tests\book\Unit\Menu\BookLocalTasksTest.
  */
 
-namespace Drupal\book\Tests\Menu;
+namespace Drupal\Tests\book\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/breakpoint/tests/src/BreakpointConfigEntityUnitTest.php b/core/modules/breakpoint/tests/src/Unit/BreakpointConfigEntityUnitTest.php
similarity index 96%
rename from core/modules/breakpoint/tests/src/BreakpointConfigEntityUnitTest.php
rename to core/modules/breakpoint/tests/src/Unit/BreakpointConfigEntityUnitTest.php
index 3b10801..660e26b 100644
--- a/core/modules/breakpoint/tests/src/BreakpointConfigEntityUnitTest.php
+++ b/core/modules/breakpoint/tests/src/Unit/BreakpointConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\breakpoint\Tests\BreakpointConfigEntityUnitTest.
+ * Contains \Drupal\Tests\breakpoint\Unit\BreakpointConfigEntityUnitTest.
  */
 
-namespace Drupal\breakpoint\Tests;
+namespace Drupal\Tests\breakpoint\Unit;
 
 use Drupal\breakpoint\Entity\Breakpoint;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/breakpoint/tests/src/BreakpointGroupConfigEntityUnitTest.php b/core/modules/breakpoint/tests/src/Unit/BreakpointGroupConfigEntityUnitTest.php
similarity index 97%
rename from core/modules/breakpoint/tests/src/BreakpointGroupConfigEntityUnitTest.php
rename to core/modules/breakpoint/tests/src/Unit/BreakpointGroupConfigEntityUnitTest.php
index 61ad1ac..38aa37d 100644
--- a/core/modules/breakpoint/tests/src/BreakpointGroupConfigEntityUnitTest.php
+++ b/core/modules/breakpoint/tests/src/Unit/BreakpointGroupConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\breakpoint\Tests\BreakpointGroupConfigEntityUnitTest.
+ * Contains \Drupal\Tests\breakpoint\Unit\BreakpointGroupConfigEntityUnitTest.
  */
 
-namespace Drupal\breakpoint\Tests;
+namespace Drupal\Tests\breakpoint\Unit;
 
 use Drupal\breakpoint\Entity\Breakpoint;
 use Drupal\breakpoint\Entity\BreakpointGroup;
diff --git a/core/modules/breakpoint/tests/src/BreakpointMediaQueryTest.php b/core/modules/breakpoint/tests/src/Unit/BreakpointMediaQueryTest.php
similarity index 96%
rename from core/modules/breakpoint/tests/src/BreakpointMediaQueryTest.php
rename to core/modules/breakpoint/tests/src/Unit/BreakpointMediaQueryTest.php
index c8ab81d..086fc4d 100644
--- a/core/modules/breakpoint/tests/src/BreakpointMediaQueryTest.php
+++ b/core/modules/breakpoint/tests/src/Unit/BreakpointMediaQueryTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Definition of Drupal\breakpoint\Tests\BreakpointMediaQueryTest.
+ * Definition of Drupal\Tests\breakpoint\Unit\BreakpointMediaQueryTest.
  */
 
-namespace Drupal\breakpoint\Tests;
+namespace Drupal\Tests\breakpoint\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\breakpoint\Entity\Breakpoint;
diff --git a/core/modules/comment/tests/src/CommentLinkBuilderTest.php b/core/modules/comment/tests/src/Unit/CommentLinkBuilderTest.php
similarity index 99%
rename from core/modules/comment/tests/src/CommentLinkBuilderTest.php
rename to core/modules/comment/tests/src/Unit/CommentLinkBuilderTest.php
index 628a5e1..2993f28 100644
--- a/core/modules/comment/tests/src/CommentLinkBuilderTest.php
+++ b/core/modules/comment/tests/src/Unit/CommentLinkBuilderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\comment\Tests\CommentLinkBuilderTest.
+ * Contains \Drupal\Tests\comment\Unit\CommentLinkBuilderTest.
  */
 
-namespace Drupal\comment\Tests;
+namespace Drupal\Tests\comment\Unit;
 
 use Drupal\comment\CommentLinkBuilder;
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
diff --git a/core/modules/comment/tests/src/CommentManagerTest.php b/core/modules/comment/tests/src/Unit/CommentManagerTest.php
similarity index 95%
rename from core/modules/comment/tests/src/CommentManagerTest.php
rename to core/modules/comment/tests/src/Unit/CommentManagerTest.php
index b001165..0cb5d93 100644
--- a/core/modules/comment/tests/src/CommentManagerTest.php
+++ b/core/modules/comment/tests/src/Unit/CommentManagerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\comment\Tests\CommentManagerTest.
+ * Contains \Drupal\Tests\comment\Unit\CommentManagerTest.
  */
 
-namespace Drupal\comment\Tests;
+namespace Drupal\Tests\comment\Unit;
 
 use Drupal\comment\CommentManager;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/comment/tests/src/CommentStatisticsUnitTest.php b/core/modules/comment/tests/src/Unit/CommentStatisticsUnitTest.php
similarity index 96%
rename from core/modules/comment/tests/src/CommentStatisticsUnitTest.php
rename to core/modules/comment/tests/src/Unit/CommentStatisticsUnitTest.php
index f625b48..6439fec 100644
--- a/core/modules/comment/tests/src/CommentStatisticsUnitTest.php
+++ b/core/modules/comment/tests/src/Unit/CommentStatisticsUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\comment\Tests\CommentStatisticsTest.
+ * Contains \Drupal\Tests\comment\Unit\CommentStatisticsTest.
  */
 
-namespace Drupal\comment\Tests;
+namespace Drupal\Tests\comment\Unit;
 
 use Drupal\comment\CommentStatistics;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/comment/tests/src/Entity/CommentLockTest.php b/core/modules/comment/tests/src/Unit/Entity/CommentLockTest.php
similarity index 97%
rename from core/modules/comment/tests/src/Entity/CommentLockTest.php
rename to core/modules/comment/tests/src/Unit/Entity/CommentLockTest.php
index af6a7f7..a540a7e 100644
--- a/core/modules/comment/tests/src/Entity/CommentLockTest.php
+++ b/core/modules/comment/tests/src/Unit/Entity/CommentLockTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\comment\Tests\Entity\CommentTest
+ * Contains \Drupal\Tests\comment\Unit\Entity\CommentTest
  */
 
-namespace Drupal\comment\Tests\Entity;
+namespace Drupal\Tests\comment\Unit\Entity;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Entity\EntityType;
diff --git a/core/modules/config/tests/src/Menu/ConfigLocalTasksTest.php b/core/modules/config/tests/src/Unit/Menu/ConfigLocalTasksTest.php
similarity index 92%
rename from core/modules/config/tests/src/Menu/ConfigLocalTasksTest.php
rename to core/modules/config/tests/src/Unit/Menu/ConfigLocalTasksTest.php
index 54edad8..a757378 100644
--- a/core/modules/config/tests/src/Menu/ConfigLocalTasksTest.php
+++ b/core/modules/config/tests/src/Unit/Menu/ConfigLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\config\Tests\Menu\ConfigLocalTasksTest.
+ * Contains \Drupal\Tests\config\Unit\Menu\ConfigLocalTasksTest.
  */
 
-namespace Drupal\config\Tests\Menu;
+namespace Drupal\Tests\config\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/config_translation/tests/src/ConfigEntityMapperTest.php b/core/modules/config_translation/tests/src/Unit/ConfigEntityMapperTest.php
similarity index 97%
rename from core/modules/config_translation/tests/src/ConfigEntityMapperTest.php
rename to core/modules/config_translation/tests/src/Unit/ConfigEntityMapperTest.php
index 904895f..69828f6 100644
--- a/core/modules/config_translation/tests/src/ConfigEntityMapperTest.php
+++ b/core/modules/config_translation/tests/src/Unit/ConfigEntityMapperTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\config_translation\Tests\ConfigEntityMapperTest.
+ * Contains \Drupal\Tests\config_translation\Unit\ConfigEntityMapperTest.
  */
 
-namespace Drupal\config_translation\Tests;
+namespace Drupal\Tests\config_translation\Unit;
 
 use Drupal\config_translation\ConfigEntityMapper;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/config_translation/tests/src/ConfigMapperManagerTest.php b/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
similarity index 98%
rename from core/modules/config_translation/tests/src/ConfigMapperManagerTest.php
rename to core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
index 5904840..c28b663 100644
--- a/core/modules/config_translation/tests/src/ConfigMapperManagerTest.php
+++ b/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\config_translation\Tests\ConfigMapperManagerTest.
+ * Contains \Drupal\Tests\config_translation\Unit\ConfigMapperManagerTest.
  */
 
-namespace Drupal\config_translation\Tests;
+namespace Drupal\Tests\config_translation\Unit;
 
 use Drupal\config_translation\ConfigMapperManager;
 use Drupal\Core\Language\Language;
diff --git a/core/modules/config_translation/tests/src/ConfigNamesMapperTest.php b/core/modules/config_translation/tests/src/Unit/ConfigNamesMapperTest.php
similarity index 99%
rename from core/modules/config_translation/tests/src/ConfigNamesMapperTest.php
rename to core/modules/config_translation/tests/src/Unit/ConfigNamesMapperTest.php
index 3794f95..5b19122 100644
--- a/core/modules/config_translation/tests/src/ConfigNamesMapperTest.php
+++ b/core/modules/config_translation/tests/src/Unit/ConfigNamesMapperTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\config_translation\Tests\ConfigNamesMapperTest.
+ * Contains \Drupal\Tests\config_translation\Unit\ConfigNamesMapperTest.
  */
 
-namespace Drupal\config_translation\Tests;
+namespace Drupal\Tests\config_translation\Unit;
 
 use Drupal\config_translation\ConfigNamesMapper;
 use Drupal\Core\Config\ConfigFactoryInterface;
@@ -33,7 +33,7 @@ class ConfigNamesMapperTest extends UnitTestCase {
    *
    * @see \Drupal\config_translation\ConfigNamesMapper
    *
-   * @var \Drupal\config_translation\Tests\TestConfigNamesMapper
+   * @var \Drupal\Tests\config_translation\Unit\TestConfigNamesMapper
    */
   protected $configNamesMapper;
 
diff --git a/core/modules/content_translation/tests/src/Access/ContentTranslationManageAccessCheckTest.php b/core/modules/content_translation/tests/src/Unit/Access/ContentTranslationManageAccessCheckTest.php
similarity index 95%
rename from core/modules/content_translation/tests/src/Access/ContentTranslationManageAccessCheckTest.php
rename to core/modules/content_translation/tests/src/Unit/Access/ContentTranslationManageAccessCheckTest.php
index ffbb60b..7bdfc98 100644
--- a/core/modules/content_translation/tests/src/Access/ContentTranslationManageAccessCheckTest.php
+++ b/core/modules/content_translation/tests/src/Unit/Access/ContentTranslationManageAccessCheckTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\content_translation\Tests\Access\ContentTranslationManageAccessCheckTest.
+ * Contains \Drupal\Tests\content_translation\Unit\Access\ContentTranslationManageAccessCheckTest.
  */
 
-namespace Drupal\content_translation\Tests\Access;
+namespace Drupal\Tests\content_translation\Unit\Access;
 
 use Drupal\content_translation\Access\ContentTranslationManageAccessCheck;
 use Drupal\Core\Access\AccessInterface;
diff --git a/core/modules/content_translation/tests/src/Menu/ContentTranslationLocalTasksTest.php b/core/modules/content_translation/tests/src/Unit/Menu/ContentTranslationLocalTasksTest.php
similarity index 94%
rename from core/modules/content_translation/tests/src/Menu/ContentTranslationLocalTasksTest.php
rename to core/modules/content_translation/tests/src/Unit/Menu/ContentTranslationLocalTasksTest.php
index 46813a3..b8d799a 100644
--- a/core/modules/content_translation/tests/src/Menu/ContentTranslationLocalTasksTest.php
+++ b/core/modules/content_translation/tests/src/Unit/Menu/ContentTranslationLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Tests\Menu\BlockLocalTasksTest.
+ * Contains \Drupal\Tests\block\Unit\Menu\BlockLocalTasksTest.
  */
 
-namespace Drupal\content_translation\Tests\Menu;
+namespace Drupal\Tests\content_translation\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/editor/tests/src/EditorConfigEntityUnitTest.php b/core/modules/editor/tests/src/Unit/EditorConfigEntityUnitTest.php
similarity index 97%
rename from core/modules/editor/tests/src/EditorConfigEntityUnitTest.php
rename to core/modules/editor/tests/src/Unit/EditorConfigEntityUnitTest.php
index d4228da..5036532 100644
--- a/core/modules/editor/tests/src/EditorConfigEntityUnitTest.php
+++ b/core/modules/editor/tests/src/Unit/EditorConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\editor\Tests\EditorConfigEntityUnitTest.
+ * Contains \Drupal\Tests\editor\Unit\EditorConfigEntityUnitTest.
  */
 
-namespace Drupal\editor\Tests;
+namespace Drupal\Tests\editor\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\editor\Entity\Editor;
diff --git a/core/modules/editor/tests/src/EditorXssFilter/StandardTest.php b/core/modules/editor/tests/src/Unit/EditorXssFilter/StandardTest.php
similarity index 99%
rename from core/modules/editor/tests/src/EditorXssFilter/StandardTest.php
rename to core/modules/editor/tests/src/Unit/EditorXssFilter/StandardTest.php
index befefd5..bd7bf0c 100644
--- a/core/modules/editor/tests/src/EditorXssFilter/StandardTest.php
+++ b/core/modules/editor/tests/src/Unit/EditorXssFilter/StandardTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\editor\Tests\EditorXssFilter\StandardTest.
+ * Contains \Drupal\Tests\editor\Unit\EditorXssFilter\StandardTest.
  */
 
-namespace Drupal\editor\Tests\EditorXssFilter;
+namespace Drupal\Tests\editor\Unit\EditorXssFilter;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\filter\Plugin\FilterInterface;
@@ -62,7 +62,7 @@ protected function setUp() {
    * Drupal\Component\Utility\Xss. See \Drupal\Tests\Component\Utility\XssTest::testBlacklistMode()
    * for more detailed test coverage.
    *
-   * @see \Drupal\editor\Tests\editor\EditorXssFilter\StandardTest::testFilterXss()
+   * @see \Drupal\Tests\editor\Unit\editor\EditorXssFilter\StandardTest::testFilterXss()
    * @see \Drupal\Tests\Component\Utility\XssTest::testBlacklistMode()
    */
   public function providerTestFilterXss() {
diff --git a/core/modules/field/tests/src/FieldInstanceConfigEntityUnitTest.php b/core/modules/field/tests/src/Unit/FieldInstanceConfigEntityUnitTest.php
similarity index 98%
rename from core/modules/field/tests/src/FieldInstanceConfigEntityUnitTest.php
rename to core/modules/field/tests/src/Unit/FieldInstanceConfigEntityUnitTest.php
index 1df4023..8dec951 100644
--- a/core/modules/field/tests/src/FieldInstanceConfigEntityUnitTest.php
+++ b/core/modules/field/tests/src/Unit/FieldInstanceConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\field\Tests\FieldInstanceConfigEntityUnitTest.
+ * Contains \Drupal\Tests\field\Unit\FieldInstanceConfigEntityUnitTest.
  */
 
-namespace Drupal\field\Tests;
+namespace Drupal\Tests\field\Unit;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/field/tests/src/FieldStorageConfigEntityUnitTest.php b/core/modules/field/tests/src/Unit/FieldStorageConfigEntityUnitTest.php
similarity index 96%
rename from core/modules/field/tests/src/FieldStorageConfigEntityUnitTest.php
rename to core/modules/field/tests/src/Unit/FieldStorageConfigEntityUnitTest.php
index c6927c3..3c536a3 100644
--- a/core/modules/field/tests/src/FieldStorageConfigEntityUnitTest.php
+++ b/core/modules/field/tests/src/Unit/FieldStorageConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\field\Tests\FieldStorageConfigEntityUnitTest.
+ * Contains \Drupal\Tests\field\Unit\FieldStorageConfigEntityUnitTest.
  */
 
-namespace Drupal\field\Tests;
+namespace Drupal\Tests\field\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\field\Entity\FieldStorageConfig;
diff --git a/core/modules/forum/tests/src/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php
similarity index 97%
rename from core/modules/forum/tests/src/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php
rename to core/modules/forum/tests/src/Unit/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php
index ad5840b..3d7e3ed 100644
--- a/core/modules/forum/tests/src/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php
+++ b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumBreadcrumbBuilderBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\forum\Tests\Breadcrumb\ForumBreadcrumbBuilderBaseTest.
+ * Contains \Drupal\Tests\forum\Unit\Breadcrumb\ForumBreadcrumbBuilderBaseTest.
  */
 
-namespace Drupal\forum\Tests\Breadcrumb;
+namespace Drupal\Tests\forum\Unit\Breadcrumb;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/forum/tests/src/Breadcrumb/ForumListingBreadcrumbBuilderTest.php b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumListingBreadcrumbBuilderTest.php
similarity index 98%
rename from core/modules/forum/tests/src/Breadcrumb/ForumListingBreadcrumbBuilderTest.php
rename to core/modules/forum/tests/src/Unit/Breadcrumb/ForumListingBreadcrumbBuilderTest.php
index e32e287..6789b7a 100644
--- a/core/modules/forum/tests/src/Breadcrumb/ForumListingBreadcrumbBuilderTest.php
+++ b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumListingBreadcrumbBuilderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\forum\Tests\Breadcrumb\ForumListingBreadcrumbBuilderTest.
+ * Contains \Drupal\Tests\forum\Unit\Breadcrumb\ForumListingBreadcrumbBuilderTest.
  */
 
-namespace Drupal\forum\Tests\Breadcrumb;
+namespace Drupal\Tests\forum\Unit\Breadcrumb;
 
 use Drupal\Tests\UnitTestCase;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
diff --git a/core/modules/forum/tests/src/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php
similarity index 98%
rename from core/modules/forum/tests/src/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php
rename to core/modules/forum/tests/src/Unit/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php
index 86cad8e..2182746 100644
--- a/core/modules/forum/tests/src/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php
+++ b/core/modules/forum/tests/src/Unit/Breadcrumb/ForumNodeBreadcrumbBuilderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\forum\Tests\Breadcrumb\ForumNodeBreadcrumbBuilderTest.
+ * Contains \Drupal\Tests\forum\Unit\Breadcrumb\ForumNodeBreadcrumbBuilderTest.
  */
 
-namespace Drupal\forum\Tests\Breadcrumb;
+namespace Drupal\Tests\forum\Unit\Breadcrumb;
 
 use Drupal\Tests\UnitTestCase;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
diff --git a/core/modules/forum/tests/src/ForumManagerTest.php b/core/modules/forum/tests/src/Unit/ForumManagerTest.php
similarity index 96%
rename from core/modules/forum/tests/src/ForumManagerTest.php
rename to core/modules/forum/tests/src/Unit/ForumManagerTest.php
index 8a785e6..ef8a28d 100644
--- a/core/modules/forum/tests/src/ForumManagerTest.php
+++ b/core/modules/forum/tests/src/Unit/ForumManagerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\forum\Tests\ForumManagerTest.
+ * Contains \Drupal\Tests\forum\Unit\ForumManagerTest.
  */
 
-namespace Drupal\forum\Tests;
+namespace Drupal\Tests\forum\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/hal/tests/src/FieldItemNormalizerDenormalizeExceptionsUnitTest.php b/core/modules/hal/tests/src/Unit/FieldItemNormalizerDenormalizeExceptionsUnitTest.php
similarity index 87%
rename from core/modules/hal/tests/src/FieldItemNormalizerDenormalizeExceptionsUnitTest.php
rename to core/modules/hal/tests/src/Unit/FieldItemNormalizerDenormalizeExceptionsUnitTest.php
index 5026e61..1457a26 100644
--- a/core/modules/hal/tests/src/FieldItemNormalizerDenormalizeExceptionsUnitTest.php
+++ b/core/modules/hal/tests/src/Unit/FieldItemNormalizerDenormalizeExceptionsUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\hal\Tests\FieldItemNormalizerDenormalizeExceptionsUnitTest.
+ * Contains \Drupal\Tests\hal\Unit\FieldItemNormalizerDenormalizeExceptionsUnitTest.
  */
 
-namespace Drupal\hal\Tests;
+namespace Drupal\Tests\hal\Unit;
 
 use Drupal\hal\Normalizer\FieldItemNormalizer;
 
diff --git a/core/modules/hal/tests/src/FieldNormalizerDenormalizeExceptionsUnitTest.php b/core/modules/hal/tests/src/Unit/FieldNormalizerDenormalizeExceptionsUnitTest.php
similarity index 87%
rename from core/modules/hal/tests/src/FieldNormalizerDenormalizeExceptionsUnitTest.php
rename to core/modules/hal/tests/src/Unit/FieldNormalizerDenormalizeExceptionsUnitTest.php
index 941c658..935ac74 100644
--- a/core/modules/hal/tests/src/FieldNormalizerDenormalizeExceptionsUnitTest.php
+++ b/core/modules/hal/tests/src/Unit/FieldNormalizerDenormalizeExceptionsUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\hal\Tests\FieldNormalizerDenormalizeExceptionsUnitTest.
+ * Contains \Drupal\Tests\hal\Unit\FieldNormalizerDenormalizeExceptionsUnitTest.
  */
 
-namespace Drupal\hal\Tests;
+namespace Drupal\Tests\hal\Unit;
 
 use Drupal\hal\Normalizer\FieldNormalizer;
 
diff --git a/core/modules/hal/tests/src/NormalizerDenormalizeExceptionsUnitTestBase.php b/core/modules/hal/tests/src/Unit/NormalizerDenormalizeExceptionsUnitTestBase.php
similarity index 89%
rename from core/modules/hal/tests/src/NormalizerDenormalizeExceptionsUnitTestBase.php
rename to core/modules/hal/tests/src/Unit/NormalizerDenormalizeExceptionsUnitTestBase.php
index f16b223..4c6576d 100644
--- a/core/modules/hal/tests/src/NormalizerDenormalizeExceptionsUnitTestBase.php
+++ b/core/modules/hal/tests/src/Unit/NormalizerDenormalizeExceptionsUnitTestBase.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\hal\Tests\NormalizerDenormalizeExceptionsUnitTestBase.
+ * Contains \Drupal\Tests\hal\Unit\NormalizerDenormalizeExceptionsUnitTestBase.
  */
 
-namespace Drupal\hal\Tests;
+namespace Drupal\Tests\hal\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/language/tests/src/LanguageNegotiationUrlTest.php b/core/modules/language/tests/src/Unit/LanguageNegotiationUrlTest.php
similarity index 97%
rename from core/modules/language/tests/src/LanguageNegotiationUrlTest.php
rename to core/modules/language/tests/src/Unit/LanguageNegotiationUrlTest.php
index 13229ea..7f2684b 100644
--- a/core/modules/language/tests/src/LanguageNegotiationUrlTest.php
+++ b/core/modules/language/tests/src/Unit/LanguageNegotiationUrlTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\LanguageNegotiationUrlTest.
+ * Contains \Drupal\Tests\language\Unit\LanguageNegotiationUrlTest.
  */
 
-namespace Drupal\language\Tests;
+namespace Drupal\Tests\language\Unit;
 
 use Drupal\Core\Session\UserSession;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/language/tests/src/Menu/LanguageLocalTasksTest.php b/core/modules/language/tests/src/Unit/Menu/LanguageLocalTasksTest.php
similarity index 91%
rename from core/modules/language/tests/src/Menu/LanguageLocalTasksTest.php
rename to core/modules/language/tests/src/Unit/Menu/LanguageLocalTasksTest.php
index 1d583b8..dd1eff6 100644
--- a/core/modules/language/tests/src/Menu/LanguageLocalTasksTest.php
+++ b/core/modules/language/tests/src/Unit/Menu/LanguageLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\language\Tests\Menu\LanguageLocalTasksTest.
+ * Contains \Drupal\Tests\language\Unit\Menu\LanguageLocalTasksTest.
  */
 
-namespace Drupal\language\Tests\Menu;
+namespace Drupal\Tests\language\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/locale/tests/src/LocaleLookupTest.php b/core/modules/locale/tests/src/Unit/LocaleLookupTest.php
similarity index 98%
rename from core/modules/locale/tests/src/LocaleLookupTest.php
rename to core/modules/locale/tests/src/Unit/LocaleLookupTest.php
index 1295d7b..296054d 100644
--- a/core/modules/locale/tests/src/LocaleLookupTest.php
+++ b/core/modules/locale/tests/src/Unit/LocaleLookupTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleLookupTest.
+ * Contains \Drupal\Tests\locale\Unit\LocaleLookupTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\locale\LocaleLookup;
diff --git a/core/modules/locale/tests/src/LocaleTranslationTest.php b/core/modules/locale/tests/src/Unit/LocaleTranslationTest.php
similarity index 93%
rename from core/modules/locale/tests/src/LocaleTranslationTest.php
rename to core/modules/locale/tests/src/Unit/LocaleTranslationTest.php
index e3f3f25..03c1536 100644
--- a/core/modules/locale/tests/src/LocaleTranslationTest.php
+++ b/core/modules/locale/tests/src/Unit/LocaleTranslationTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\LocaleTranslationTest.
+ * Contains \Drupal\Tests\locale\Unit\LocaleTranslationTest.
  */
 
-namespace Drupal\locale\Tests;
+namespace Drupal\Tests\locale\Unit;
 
 use Drupal\locale\LocaleTranslation;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/locale/tests/src/Menu/LocaleLocalTasksTest.php b/core/modules/locale/tests/src/Unit/Menu/LocaleLocalTasksTest.php
similarity index 90%
rename from core/modules/locale/tests/src/Menu/LocaleLocalTasksTest.php
rename to core/modules/locale/tests/src/Unit/Menu/LocaleLocalTasksTest.php
index dcedac1..e30f676 100644
--- a/core/modules/locale/tests/src/Menu/LocaleLocalTasksTest.php
+++ b/core/modules/locale/tests/src/Unit/Menu/LocaleLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\locale\Tests\Menu\LocaleLocalTasksTest.
+ * Contains \Drupal\Tests\locale\Unit\Menu\LocaleLocalTasksTest.
  */
 
-namespace Drupal\locale\Tests\Menu;
+namespace Drupal\Tests\locale\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/migrate/tests/src/MigrateExecutableTest.php b/core/modules/migrate/tests/src/Unit/MigrateExecutableTest.php
similarity index 98%
rename from core/modules/migrate/tests/src/MigrateExecutableTest.php
rename to core/modules/migrate/tests/src/Unit/MigrateExecutableTest.php
index 4499771..517b6c0 100644
--- a/core/modules/migrate/tests/src/MigrateExecutableTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateExecutableTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateExecutableTest.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateExecutableTest.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\migrate\Entity\MigrationInterface;
 use Drupal\migrate\Plugin\MigrateIdMapInterface;
@@ -13,7 +13,7 @@
 use Drupal\migrate\Row;
 
 /**
- * @coversDefaultClass \Drupal\migrate\Tests\MigrateExecutableTest
+ * @coversDefaultClass \Drupal\Tests\migrate\Unit\MigrateExecutableTest
  * @group migrate
  */
 class MigrateExecutableTest extends MigrateTestCase {
@@ -35,7 +35,7 @@ class MigrateExecutableTest extends MigrateTestCase {
   /**
    * The tested migrate executable.
    *
-   * @var \Drupal\migrate\Tests\TestMigrateExecutable
+   * @var \Drupal\Tests\migrate\Unit\TestMigrateExecutable
    */
   protected $executable;
 
diff --git a/core/modules/migrate/tests/src/MigrateExecuteableMemoryExceededTest.php b/core/modules/migrate/tests/src/Unit/MigrateExecuteableMemoryExceededTest.php
similarity index 95%
rename from core/modules/migrate/tests/src/MigrateExecuteableMemoryExceededTest.php
rename to core/modules/migrate/tests/src/Unit/MigrateExecuteableMemoryExceededTest.php
index c296f30..c1d2966 100644
--- a/core/modules/migrate/tests/src/MigrateExecuteableMemoryExceededTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateExecuteableMemoryExceededTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateExecuteableMemoryExceeded.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateExecuteableMemoryExceeded.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 /**
  * Tests the \Drupal\migrate\MigrateExecutable::memoryExceeded() method.
@@ -31,7 +31,7 @@ class MigrateExecuteableMemoryExceededTest extends MigrateTestCase {
   /**
    * The tested migrate executable.
    *
-   * @var \Drupal\migrate\Tests\TestMigrateExecutable
+   * @var \Drupal\Tests\migrate\Unit\TestMigrateExecutable
    */
   protected $executable;
 
diff --git a/core/modules/migrate/tests/src/MigrateSqlIdMapEnsureTablesTest.php b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapEnsureTablesTest.php
similarity index 98%
rename from core/modules/migrate/tests/src/MigrateSqlIdMapEnsureTablesTest.php
rename to core/modules/migrate/tests/src/Unit/MigrateSqlIdMapEnsureTablesTest.php
index d353d2d..ceaddbb 100644
--- a/core/modules/migrate/tests/src/MigrateSqlIdMapEnsureTablesTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapEnsureTablesTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateSqlIdMapEnsureTablesTest.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateSqlIdMapEnsureTablesTest.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\migrate\Plugin\MigrateIdMapInterface;
 
diff --git a/core/modules/migrate/tests/src/MigrateSqlIdMapTest.php b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
similarity index 99%
rename from core/modules/migrate/tests/src/MigrateSqlIdMapTest.php
rename to core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
index f7828a2..b741780 100644
--- a/core/modules/migrate/tests/src/MigrateSqlIdMapTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateSqlIdMapTestCase.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateSqlIdMapTestCase.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\migrate\Entity\MigrationInterface;
 use Drupal\migrate\MigrateException;
@@ -54,7 +54,7 @@ class MigrateSqlIdMapTest extends MigrateTestCase {
    * @param string $prefix
    *   (optional) The database prefix.
    *
-   * @return \Drupal\migrate\Tests\TestSqlIdMap
+   * @return \Drupal\Tests\migrate\Unit\TestSqlIdMap
    *   A SQL ID map plugin test instance.
    */
   protected function getIdMap($database_contents = array(), $connection_options = array(), $prefix = '') {
diff --git a/core/modules/migrate/tests/src/MigrateSqlSourceTestCase.php b/core/modules/migrate/tests/src/Unit/MigrateSqlSourceTestCase.php
similarity index 92%
rename from core/modules/migrate/tests/src/MigrateSqlSourceTestCase.php
rename to core/modules/migrate/tests/src/Unit/MigrateSqlSourceTestCase.php
index 471ed76..9319ba8 100644
--- a/core/modules/migrate/tests/src/MigrateSqlSourceTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSqlSourceTestCase.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateSqlSourceTestCase.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\migrate\Source;
@@ -79,7 +79,7 @@ protected function setUp() {
       ->method('getHighWater')
       ->will($this->returnValue(static::ORIGINAL_HIGH_WATER));
     // Need the test class, not the original because we need a setDatabase method. This is not pretty :/
-    $plugin_class  = preg_replace('/^(Drupal\\\\\w+\\\\)Plugin\\\\migrate(\\\\source(\\\\.+)?\\\\)([^\\\\]+)$/', '\1Tests\2Test\4', static::PLUGIN_CLASS);
+    $plugin_class  = preg_replace('/^Drupal\\\\(\w+)\\\\Plugin\\\\migrate(\\\\source(\\\\.+)?\\\\)([^\\\\]+)$/', 'Drupal\\Tests\\\$1\\Unit$2Test$4', static::PLUGIN_CLASS);
     $plugin = new $plugin_class($this->migrationConfiguration['source'], $this->migrationConfiguration['source']['plugin'], array(), $migration);
     $plugin->setDatabase($this->getDatabase($this->databaseContents + array('test_map' => array())));
     $plugin->setModuleHandler($module_handler);
diff --git a/core/modules/migrate/tests/src/MigrateTestCase.php b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php
similarity index 97%
rename from core/modules/migrate/tests/src/MigrateTestCase.php
rename to core/modules/migrate/tests/src/Unit/MigrateTestCase.php
index 279ffa9..75348fa 100644
--- a/core/modules/migrate/tests/src/MigrateTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateTestCase.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\MigrateTestCase.
+ * Contains \Drupal\Tests\migrate\Unit\MigrateTestCase.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\Core\Database\Driver\fake\FakeConnection;
diff --git a/core/modules/migrate/tests/src/RowTest.php b/core/modules/migrate/tests/src/Unit/RowTest.php
similarity index 98%
rename from core/modules/migrate/tests/src/RowTest.php
rename to core/modules/migrate/tests/src/Unit/RowTest.php
index 2ba35c0..ba941df 100644
--- a/core/modules/migrate/tests/src/RowTest.php
+++ b/core/modules/migrate/tests/src/Unit/RowTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\RowTest.
+ * Contains \Drupal\Tests\migrate\Unit\RowTest.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\migrate\Plugin\MigrateIdMapInterface;
 use Drupal\migrate\Row;
diff --git a/core/modules/migrate/tests/src/TestMigrateExecutable.php b/core/modules/migrate/tests/src/Unit/TestMigrateExecutable.php
similarity index 98%
rename from core/modules/migrate/tests/src/TestMigrateExecutable.php
rename to core/modules/migrate/tests/src/Unit/TestMigrateExecutable.php
index 8746236..467e022 100644
--- a/core/modules/migrate/tests/src/TestMigrateExecutable.php
+++ b/core/modules/migrate/tests/src/Unit/TestMigrateExecutable.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\TestMigrateExecutable.
+ * Contains \Drupal\Tests\migrate\Unit\TestMigrateExecutable.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\Core\StringTranslation\TranslationInterface;
 use Drupal\migrate\MigrateExecutable;
diff --git a/core/modules/migrate/tests/src/TestSqlIdMap.php b/core/modules/migrate/tests/src/Unit/TestSqlIdMap.php
similarity index 95%
rename from core/modules/migrate/tests/src/TestSqlIdMap.php
rename to core/modules/migrate/tests/src/Unit/TestSqlIdMap.php
index cad8b3b..36c731f 100644
--- a/core/modules/migrate/tests/src/TestSqlIdMap.php
+++ b/core/modules/migrate/tests/src/Unit/TestSqlIdMap.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\TestSqlIdMap.
+ * Contains \Drupal\Tests\migrate\Unit\TestSqlIdMap.
  */
 
-namespace Drupal\migrate\Tests;
+namespace Drupal\Tests\migrate\Unit;
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\Database\Connection;
diff --git a/core/modules/migrate_drupal/src/Tests/destination/ConfigDestinationTest.php b/core/modules/migrate/tests/src/Unit/destination/ConfigTest.php
similarity index 80%
rename from core/modules/migrate_drupal/src/Tests/destination/ConfigDestinationTest.php
rename to core/modules/migrate/tests/src/Unit/destination/ConfigTest.php
index 2bbbc11..8ed3f6d 100644
--- a/core/modules/migrate_drupal/src/Tests/destination/ConfigDestinationTest.php
+++ b/core/modules/migrate/tests/src/Unit/destination/ConfigTest.php
@@ -2,19 +2,19 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\destination\ConfigDestinationTest.
+ * Contains \Drupal\Tests\migrate\Unit\destination\ConfigTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\destination;
+namespace Drupal\Tests\migrate\Unit\destination;
 
 use Drupal\migrate\Plugin\migrate\destination\Config;
 use Drupal\Tests\UnitTestCase;
 
 /**
- * @coversDefaultClass \Drupal\migrate_drupal\Plugin\migrate\destination\Config
- * @group migrate_drupal
+ * @coversDefaultClass \Drupal\migrate\Plugin\migrate\destination\Config
+ * @group migrate
  */
-class ConfigDestinationTest extends UnitTestCase {
+class ConfigTest extends UnitTestCase {
 
   /**
    * Test the import method.
diff --git a/core/modules/migrate/tests/src/destination/PerComponentEntityDisplayTest.php b/core/modules/migrate/tests/src/Unit/destination/PerComponentEntityDisplayTest.php
similarity index 91%
rename from core/modules/migrate/tests/src/destination/PerComponentEntityDisplayTest.php
rename to core/modules/migrate/tests/src/Unit/destination/PerComponentEntityDisplayTest.php
index ac26f3a..d00008b 100644
--- a/core/modules/migrate/tests/src/destination/PerComponentEntityDisplayTest.php
+++ b/core/modules/migrate/tests/src/Unit/destination/PerComponentEntityDisplayTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\destination\EntityDisplayTest.
+ * Contains \Drupal\Tests\migrate\Unit\destination\EntityDisplayTest.
  */
 
-namespace Drupal\migrate\Tests\destination;
+namespace Drupal\Tests\migrate\Unit\destination;
 
 use Drupal\migrate\Plugin\migrate\destination\ComponentEntityDisplayBase;
 use Drupal\migrate\Row;
-use Drupal\migrate\Tests\MigrateTestCase;
+use Drupal\Tests\migrate\Unit\MigrateTestCase;
 
 /**
  * Tests the entity display destination plugin.
diff --git a/core/modules/migrate/tests/src/destination/PerComponentEntityFormDisplayTest.php b/core/modules/migrate/tests/src/Unit/destination/PerComponentEntityFormDisplayTest.php
similarity index 91%
rename from core/modules/migrate/tests/src/destination/PerComponentEntityFormDisplayTest.php
rename to core/modules/migrate/tests/src/Unit/destination/PerComponentEntityFormDisplayTest.php
index d1aa648..bca24a4 100644
--- a/core/modules/migrate/tests/src/destination/PerComponentEntityFormDisplayTest.php
+++ b/core/modules/migrate/tests/src/Unit/destination/PerComponentEntityFormDisplayTest.php
@@ -2,14 +2,14 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\destination\EntityFormDisplayTest.
+ * Contains \Drupal\Tests\migrate\Unit\destination\EntityFormDisplayTest.
  */
 
-namespace Drupal\migrate\Tests\destination;
+namespace Drupal\Tests\migrate\Unit\destination;
 
 use Drupal\migrate\Plugin\migrate\destination\PerComponentEntityFormDisplay;
 use Drupal\migrate\Row;
-use Drupal\migrate\Tests\MigrateTestCase;
+use Drupal\Tests\migrate\Unit\MigrateTestCase;
 
 /**
  * Tests the entity display destination plugin.
diff --git a/core/modules/migrate/tests/src/process/CallbackTest.php b/core/modules/migrate/tests/src/Unit/process/CallbackTest.php
similarity index 91%
rename from core/modules/migrate/tests/src/process/CallbackTest.php
rename to core/modules/migrate/tests/src/Unit/process/CallbackTest.php
index 1176791..92d1f7c 100644
--- a/core/modules/migrate/tests/src/process/CallbackTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/CallbackTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\CallbackTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\CallbackTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\Callback;
 
diff --git a/core/modules/migrate/tests/src/process/ConcatTest.php b/core/modules/migrate/tests/src/Unit/process/ConcatTest.php
similarity index 93%
rename from core/modules/migrate/tests/src/process/ConcatTest.php
rename to core/modules/migrate/tests/src/Unit/process/ConcatTest.php
index f55a997..d13c33b 100644
--- a/core/modules/migrate/tests/src/process/ConcatTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/ConcatTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\ConcatTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\ConcatTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\Concat;
 
diff --git a/core/modules/migrate/tests/src/process/DedupeEntityTest.php b/core/modules/migrate/tests/src/Unit/process/DedupeEntityTest.php
similarity index 98%
rename from core/modules/migrate/tests/src/process/DedupeEntityTest.php
rename to core/modules/migrate/tests/src/Unit/process/DedupeEntityTest.php
index 9dbca53..5e024d6 100644
--- a/core/modules/migrate/tests/src/process/DedupeEntityTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/DedupeEntityTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\DedupeEntityTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\DedupeEntityTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\DedupeEntity;
 use Drupal\Component\Utility\Unicode;
diff --git a/core/modules/migrate/tests/src/process/ExtractTest.php b/core/modules/migrate/tests/src/Unit/process/ExtractTest.php
similarity index 92%
rename from core/modules/migrate/tests/src/process/ExtractTest.php
rename to core/modules/migrate/tests/src/Unit/process/ExtractTest.php
index f4f3d1c..6fbe4b8 100644
--- a/core/modules/migrate/tests/src/process/ExtractTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/ExtractTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\ExtractTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\ExtractTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\Extract;
 
diff --git a/core/modules/migrate/tests/src/process/FlattenTest.php b/core/modules/migrate/tests/src/Unit/process/FlattenTest.php
similarity index 84%
rename from core/modules/migrate/tests/src/process/FlattenTest.php
rename to core/modules/migrate/tests/src/Unit/process/FlattenTest.php
index 179b830..9f2c4e9 100644
--- a/core/modules/migrate/tests/src/process/FlattenTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/FlattenTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\FlattenTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\FlattenTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 use Drupal\migrate\Plugin\migrate\process\Flatten;
 
 
diff --git a/core/modules/migrate/tests/src/process/GetTest.php b/core/modules/migrate/tests/src/Unit/process/GetTest.php
similarity index 98%
rename from core/modules/migrate/tests/src/process/GetTest.php
rename to core/modules/migrate/tests/src/Unit/process/GetTest.php
index ac84b42..2afff81 100644
--- a/core/modules/migrate/tests/src/process/GetTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/GetTest.php
@@ -4,7 +4,7 @@
  * Contains
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\TestGet;
 use Drupal\migrate\Row;
diff --git a/core/modules/migrate/tests/src/process/IteratorTest.php b/core/modules/migrate/tests/src/Unit/process/IteratorTest.php
similarity index 94%
rename from core/modules/migrate/tests/src/process/IteratorTest.php
rename to core/modules/migrate/tests/src/Unit/process/IteratorTest.php
index a879c22..f2b30dd 100644
--- a/core/modules/migrate/tests/src/process/IteratorTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/IteratorTest.php
@@ -1,17 +1,17 @@
 <?php
 /**
  * @file
- * Contains Drupal\migrate\Tests\process\IteratorTest.
+ * Contains Drupal\Tests\migrate\Unit\process\IteratorTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Plugin\migrate\process\Get;
 use Drupal\migrate\Plugin\migrate\process\Iterator;
 use Drupal\migrate\Plugin\migrate\process\StaticMap;
 use Drupal\migrate\Row;
-use Drupal\migrate\Tests\MigrateTestCase;
+use Drupal\Tests\migrate\Unit\MigrateTestCase;
 
 /**
  * Tests the iterator process plugin.
diff --git a/core/modules/migrate/tests/src/process/MachineNameTest.php b/core/modules/migrate/tests/src/Unit/process/MachineNameTest.php
similarity index 95%
rename from core/modules/migrate/tests/src/process/MachineNameTest.php
rename to core/modules/migrate/tests/src/Unit/process/MachineNameTest.php
index 4a48672..fa628a5 100644
--- a/core/modules/migrate/tests/src/process/MachineNameTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/MachineNameTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\MachineNameTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\MachineNameTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\TestMachineName;
 
diff --git a/core/modules/migrate/tests/src/process/MigrateProcessTestCase.php b/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
similarity index 80%
rename from core/modules/migrate/tests/src/process/MigrateProcessTestCase.php
rename to core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
index 4b45f35..6537cc3 100644
--- a/core/modules/migrate/tests/src/process/MigrateProcessTestCase.php
+++ b/core/modules/migrate/tests/src/Unit/process/MigrateProcessTestCase.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\MigrateProcessTestCase.
+ * Contains \Drupal\Tests\migrate\Unit\process\MigrateProcessTestCase.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
-use Drupal\migrate\Tests\MigrateTestCase;
+use Drupal\Tests\migrate\Unit\MigrateTestCase;
 
 abstract class MigrateProcessTestCase extends MigrateTestCase {
 
diff --git a/core/modules/migrate/tests/src/process/StaticMapTest.php b/core/modules/migrate/tests/src/Unit/process/StaticMapTest.php
similarity index 96%
rename from core/modules/migrate/tests/src/process/StaticMapTest.php
rename to core/modules/migrate/tests/src/Unit/process/StaticMapTest.php
index a3f90c0..de883ba 100644
--- a/core/modules/migrate/tests/src/process/StaticMapTest.php
+++ b/core/modules/migrate/tests/src/Unit/process/StaticMapTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\migrate\Tests\process\StaticMapTest.
+ * Contains \Drupal\Tests\migrate\Unit\process\StaticMapTest.
  */
 
-namespace Drupal\migrate\Tests\process;
+namespace Drupal\Tests\migrate\Unit\process;
 
 use Drupal\migrate\Plugin\migrate\process\StaticMap;
 
diff --git a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowSourceWithHighwaterTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowSourceWithHighwaterTest.php
similarity index 71%
rename from core/modules/migrate_drupal/tests/src/source/VariableMultiRowSourceWithHighwaterTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowSourceWithHighwaterTest.php
index 8058572..8a22224 100644
--- a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowSourceWithHighwaterTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowSourceWithHighwaterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\VariableMultiRowSourceWithHighwaterTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\VariableMultiRowSourceWithHighwaterTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
 /**
  * Tests variable multirow source w/ high water handling.
diff --git a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTest.php
similarity index 57%
rename from core/modules/migrate_drupal/tests/src/source/VariableMultiRowTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTest.php
index 7c75e3b..5a85215 100644
--- a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\VariableMultiRowTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\VariableMultiRowTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
 /**
  * Tests D6 variable multirow source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowTestBase.php b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTestBase.php
similarity index 85%
rename from core/modules/migrate_drupal/tests/src/source/VariableMultiRowTestBase.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTestBase.php
index ace536d..920337b 100644
--- a/core/modules/migrate_drupal/tests/src/source/VariableMultiRowTestBase.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/VariableMultiRowTestBase.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\VariableMultiRowTestBase.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\VariableMultiRowTestBase.
  */
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Base class for variable multirow source unit tests.
@@ -45,7 +45,7 @@
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/VariableTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/VariableTest.php
similarity index 84%
rename from core/modules/migrate_drupal/tests/src/source/VariableTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/VariableTest.php
index bfb5f10..20072bb 100644
--- a/core/modules/migrate_drupal/tests/src/source/VariableTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/VariableTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\VariableTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\VariableTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests the variable source plugin.
@@ -47,7 +47,7 @@ class VariableTest extends MigrateSqlSourceTestCase {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source;
+namespace Drupal\Tests\migrate_drupal\Unit\source;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/ActionTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ActionTest.php
similarity index 90%
rename from core/modules/migrate_drupal/tests/src/source/d6/ActionTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/ActionTest.php
index 1f128b9..3886bde 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/ActionTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ActionTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\ActionTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\ActionTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 actions source plugin.
@@ -74,7 +74,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/AggregatorFeedTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorFeedTest.php
similarity index 88%
rename from core/modules/migrate_drupal/tests/src/source/d6/AggregatorFeedTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorFeedTest.php
index 61590d8..071d308 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/AggregatorFeedTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorFeedTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\AggregatorFeedTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\AggregatorFeedTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 aggregator feed source plugin.
@@ -67,7 +67,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/AggregatorItemTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorItemTest.php
similarity index 88%
rename from core/modules/migrate_drupal/tests/src/source/d6/AggregatorItemTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorItemTest.php
index b34d143..d98d8c2 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/AggregatorItemTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/AggregatorItemTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\AggregatorItemTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\AggregatorItemTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 aggregator item source plugin.
@@ -56,7 +56,7 @@ class AggregatorItemTest extends MigrateSqlSourceTestCase {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/BlockTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/BlockTest.php
similarity index 90%
rename from core/modules/migrate_drupal/tests/src/source/d6/BlockTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/BlockTest.php
index ce2f17e..8ae4b78 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/BlockTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/BlockTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\BlockTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\BlockTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 block source plugin.
@@ -84,7 +84,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/BoxTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/BoxTest.php
similarity index 87%
rename from core/modules/migrate_drupal/tests/src/source/d6/BoxTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/BoxTest.php
index adc7253..62985a3 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/BoxTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/BoxTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\BoxesTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\BoxesTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 block boxes source plugin.
@@ -58,7 +58,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/CommentSourceWithHighwaterTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentSourceWithHighwaterTest.php
similarity index 75%
rename from core/modules/migrate_drupal/tests/src/source/d6/CommentSourceWithHighwaterTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentSourceWithHighwaterTest.php
index 697abb1..26a7e51 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/CommentSourceWithHighwaterTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentSourceWithHighwaterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\CommentSourceWithHighWaterTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\CommentSourceWithHighWaterTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 /**
  * Tests the Drupal 6 comment source w/ high water handling.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/CommentTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTest.php
similarity index 53%
rename from core/modules/migrate_drupal/tests/src/source/d6/CommentTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTest.php
index 58b0c22..660ae4a 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/CommentTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\CommentTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\CommentTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 /**
  * Tests D6 comment source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/CommentTestBase.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTestBase.php
similarity index 92%
rename from core/modules/migrate_drupal/tests/src/source/d6/CommentTestBase.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTestBase.php
index dc82868..0b8f403 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/CommentTestBase.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/CommentTestBase.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\CommentTestBase.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\CommentTestBase.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Base class for comment source unit tests.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/ContactCategoryTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ContactCategoryTest.php
similarity index 87%
rename from core/modules/migrate_drupal/tests/src/source/d6/ContactCategoryTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/ContactCategoryTest.php
index 5921a55..670c947 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/ContactCategoryTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ContactCategoryTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\ContactCategoryTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\ContactCategoryTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 contact category source plugin.
@@ -58,7 +58,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/Drupal6SqlBaseTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/Drupal6SqlBaseTest.php
similarity index 94%
rename from core/modules/migrate_drupal/tests/src/source/d6/Drupal6SqlBaseTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/Drupal6SqlBaseTest.php
index 838203e..4deb601 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/Drupal6SqlBaseTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/Drupal6SqlBaseTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\Drupal6SqlBaseTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\Drupal6SqlBaseTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateTestCase;
+use Drupal\Tests\migrate\Unit\MigrateTestCase;
 
 /**
  * Tests the D6 SQL base class.
@@ -123,7 +123,7 @@ public function testVariableGet() {
   }
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
@@ -168,7 +168,7 @@ public function query() {
    * @param \Drupal\Core\Database\Connection
    *   The new conection to use.
    *
-   * @see \Drupal\migrate\Tests\MigrateSqlTestCase
+   * @see \Drupal\Tests\migrate\Unit\MigrateSqlTestCase
    */
   public function setDatabase(Connection $database) {
     $this->database = $database;
@@ -180,7 +180,7 @@ public function setDatabase(Connection $database) {
    * @param \Drupal\Core\Extension\ModuleHandlerInterface
    *   The new module handler to use.
    *
-   * @see \Drupal\migrate\Tests\MigrateSqlTestCase
+   * @see \Drupal\Tests\migrate\Unit\MigrateSqlTestCase
    */
   public function setModuleHandler(ModuleHandlerInterface $module_handler) {
     $this->moduleHandler = $module_handler;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/FieldInstancePerViewModeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstancePerViewModeTest.php
similarity index 94%
rename from core/modules/migrate_drupal/tests/src/source/d6/FieldInstancePerViewModeTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstancePerViewModeTest.php
index 714fe1f..37fd9ea 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/FieldInstancePerViewModeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstancePerViewModeTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\FieldInstancePerViewModeTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\FieldInstancePerViewModeTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 fields per view mode source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/FieldInstanceTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstanceTest.php
similarity index 92%
rename from core/modules/migrate_drupal/tests/src/source/d6/FieldInstanceTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstanceTest.php
index f3fd49b..1eaeef9 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/FieldInstanceTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldInstanceTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\FieldInstanceTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\FieldInstanceTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 field instance source plugin.
@@ -95,7 +95,7 @@ protected function setUp() {
   }
 
 }
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/FieldTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldTest.php
similarity index 91%
rename from core/modules/migrate_drupal/tests/src/source/d6/FieldTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldTest.php
index 304183a..1deafa5 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/FieldTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FieldTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\FieldTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\FieldTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 field source plugin.
@@ -79,7 +79,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/FileTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FileTest.php
similarity index 87%
rename from core/modules/migrate_drupal/tests/src/source/d6/FileTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/FileTest.php
index c4c166c..b3aece2 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/FileTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FileTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\FileTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\FileTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 file source plugin.
@@ -62,7 +62,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/FilterFormatTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FilterFormatTest.php
similarity index 92%
rename from core/modules/migrate_drupal/tests/src/source/d6/FilterFormatTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/FilterFormatTest.php
index a2a75f7..684d85e 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/FilterFormatTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/FilterFormatTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\FilterFormatTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\FilterFormatTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 filter_formats table source plugin.
@@ -113,7 +113,7 @@ protected function setUp() {
   }
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/MenuTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/MenuTest.php
similarity index 88%
rename from core/modules/migrate_drupal/tests/src/source/d6/MenuTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/MenuTest.php
index 744d769..2b40718 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/MenuTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/MenuTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\MenuTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\MenuTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 menu source plugin.
@@ -61,7 +61,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/NodeRevisionTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeRevisionTest.php
similarity index 97%
rename from core/modules/migrate_drupal/tests/src/source/d6/NodeRevisionTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeRevisionTest.php
index e87cb67..a83c70d 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/NodeRevisionTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeRevisionTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\NodeRevisionTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\NodeRevisionTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 node revision source plugin.
@@ -335,7 +335,7 @@ public function testRetrieval() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/NodeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
similarity index 92%
rename from core/modules/migrate_drupal/tests/src/source/d6/NodeTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
index e3f5fa6..c0e528b 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/NodeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\NodeTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\NodeTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 node source plugin.
@@ -119,7 +119,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/NodeTypeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTypeTest.php
similarity index 92%
rename from core/modules/migrate_drupal/tests/src/source/d6/NodeTypeTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTypeTest.php
index adbef4a..ed784e6 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/NodeTypeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/NodeTypeTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\NodeTypeTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\NodeTypeTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 node type source plugin.
@@ -76,7 +76,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/ProfileFieldTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ProfileFieldTest.php
similarity index 91%
rename from core/modules/migrate_drupal/tests/src/source/d6/ProfileFieldTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/ProfileFieldTest.php
index 246f5c0..b66c3c9 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/ProfileFieldTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ProfileFieldTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\ProfileFieldTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\ProfileFieldTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 profile field source plugin.
@@ -92,7 +92,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/RoleTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/RoleTest.php
similarity index 93%
rename from core/modules/migrate_drupal/tests/src/source/d6/RoleTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/RoleTest.php
index e690310..8211e49 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/RoleTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/RoleTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\RoleTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\RoleTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 role source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/TermSourceWithVocabularyFilterTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermSourceWithVocabularyFilterTest.php
similarity index 77%
rename from core/modules/migrate_drupal/tests/src/source/d6/TermSourceWithVocabularyFilterTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/TermSourceWithVocabularyFilterTest.php
index a0a30cf..f209b0d 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/TermSourceWithVocabularyFilterTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermSourceWithVocabularyFilterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\TermSourceWithVocabularyFilterTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\TermSourceWithVocabularyFilterTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 /**
  * Tests the Drupal 6 taxonomy term source with vocabulary filter.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/TermTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTest.php
similarity index 54%
rename from core/modules/migrate_drupal/tests/src/source/d6/TermTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTest.php
index 056fdb6..957b7cd 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/TermTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\TermTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\TermTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 /**
  * Tests D6 taxonomy term source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/TermTestBase.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTestBase.php
similarity index 91%
rename from core/modules/migrate_drupal/tests/src/source/d6/TermTestBase.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTestBase.php
index 18f96fc..ba8129c 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/TermTestBase.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TermTestBase.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\TermTestBase.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\TermTestBase.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Base class for taxonomy term source unit tests.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/TestComment.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TestComment.php
similarity index 77%
rename from core/modules/migrate_drupal/tests/src/source/d6/TestComment.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/TestComment.php
index aa4e604..158780a 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/TestComment.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TestComment.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\TestComment.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\TestComment.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/TestTerm.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TestTerm.php
similarity index 77%
rename from core/modules/migrate_drupal/tests/src/source/d6/TestTerm.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/TestTerm.php
index f8fdf36..6cf73e4 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/TestTerm.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/TestTerm.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\TestTerm.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\TestTerm.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/UrlAliasTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UrlAliasTest.php
similarity index 85%
rename from core/modules/migrate_drupal/tests/src/source/d6/UrlAliasTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/UrlAliasTest.php
index f429e6e..ad8ff46 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/UrlAliasTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UrlAliasTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\UrlAliasTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\UrlAliasTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests the D6 url alias migrations.
@@ -54,7 +54,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/UserPictureTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UserPictureTest.php
similarity index 84%
rename from core/modules/migrate_drupal/tests/src/source/d6/UserPictureTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/UserPictureTest.php
index fb249d0..fb139fa 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/UserPictureTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UserPictureTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\UserPictureTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\UserPictureTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 user picture source plugin.
@@ -49,7 +49,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/UserTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UserTest.php
similarity index 90%
rename from core/modules/migrate_drupal/tests/src/source/d6/UserTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/UserTest.php
index 8300fc5..805e1be 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/UserTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/UserTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\CommentTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\CommentTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 user source plugin.
@@ -81,7 +81,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/ViewModeTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ViewModeTest.php
similarity index 91%
rename from core/modules/migrate_drupal/tests/src/source/d6/ViewModeTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/ViewModeTest.php
index 60e184f..af77271 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/ViewModeTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/ViewModeTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\ViewModeTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\ViewModeTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 view mode source plugin.
diff --git a/core/modules/migrate_drupal/tests/src/source/d6/VocabularyTest.php b/core/modules/migrate_drupal/tests/src/Unit/source/d6/VocabularyTest.php
similarity index 89%
rename from core/modules/migrate_drupal/tests/src/source/d6/VocabularyTest.php
rename to core/modules/migrate_drupal/tests/src/Unit/source/d6/VocabularyTest.php
index 0ba30fd..d6db86c 100644
--- a/core/modules/migrate_drupal/tests/src/source/d6/VocabularyTest.php
+++ b/core/modules/migrate_drupal/tests/src/Unit/source/d6/VocabularyTest.php
@@ -2,12 +2,12 @@
 
 /**
  * @file
- * Contains \Drupal\migrate_drupal\Tests\source\d6\VocabularyTest.
+ * Contains \Drupal\Tests\migrate_drupal\Unit\source\d6\VocabularyTest.
  */
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
-use Drupal\migrate\Tests\MigrateSqlSourceTestCase;
+use Drupal\Tests\migrate\Unit\MigrateSqlSourceTestCase;
 
 /**
  * Tests D6 vocabulary source plugin.
@@ -79,7 +79,7 @@ protected function setUp() {
 
 }
 
-namespace Drupal\migrate_drupal\Tests\source\d6;
+namespace Drupal\Tests\migrate_drupal\Unit\source\d6;
 
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
diff --git a/core/modules/node/tests/src/Plugin/views/field/NodeBulkFormTest.php b/core/modules/node/tests/src/Unit/Plugin/views/field/NodeBulkFormTest.php
similarity index 95%
rename from core/modules/node/tests/src/Plugin/views/field/NodeBulkFormTest.php
rename to core/modules/node/tests/src/Unit/Plugin/views/field/NodeBulkFormTest.php
index 21c4a94..82836e0 100644
--- a/core/modules/node/tests/src/Plugin/views/field/NodeBulkFormTest.php
+++ b/core/modules/node/tests/src/Unit/Plugin/views/field/NodeBulkFormTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\node\Tests\Plugin\views\field\NodeBulkFormTest.
+ * Contains \Drupal\Tests\node\Unit\Plugin\views\field\NodeBulkFormTest.
  */
 
-namespace Drupal\node\Tests\Plugin\views\field;
+namespace Drupal\Tests\node\Unit\Plugin\views\field;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\node\Plugin\views\field\NodeBulkForm;
diff --git a/core/modules/path/tests/src/Field/PathFieldDefinitionTest.php b/core/modules/path/tests/src/Unit/Field/PathFieldDefinitionTest.php
similarity index 79%
rename from core/modules/path/tests/src/Field/PathFieldDefinitionTest.php
rename to core/modules/path/tests/src/Unit/Field/PathFieldDefinitionTest.php
index bd3efa7..14e89e1 100644
--- a/core/modules/path/tests/src/Field/PathFieldDefinitionTest.php
+++ b/core/modules/path/tests/src/Unit/Field/PathFieldDefinitionTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\path\Tests\Plugin\Field\FieldType\PathFieldDefinitionTest.
+ * Contains \Drupal\Tests\path\Unit\Plugin\Field\FieldType\PathFieldDefinitionTest.
  */
 
-namespace Drupal\path\Tests\Field;
+namespace Drupal\Tests\path\Unit\Field;
 
 use Drupal\Tests\Core\Field\BaseFieldDefinitionTestBase;
 
@@ -26,7 +26,7 @@ protected function getPluginId() {
    * {@inheritdoc}
    */
   protected function getModuleAndPath() {
-    return array('path', dirname(dirname(dirname(__DIR__))));
+    return array('path', DRUPAL_ROOT . '/core/modules/path');
   }
 
   /**
diff --git a/core/modules/quickedit/tests/src/Access/EditEntityAccessCheckTest.php b/core/modules/quickedit/tests/src/Unit/Access/EditEntityAccessCheckTest.php
similarity index 94%
rename from core/modules/quickedit/tests/src/Access/EditEntityAccessCheckTest.php
rename to core/modules/quickedit/tests/src/Unit/Access/EditEntityAccessCheckTest.php
index 33d4ed4..e6bbd11 100644
--- a/core/modules/quickedit/tests/src/Access/EditEntityAccessCheckTest.php
+++ b/core/modules/quickedit/tests/src/Unit/Access/EditEntityAccessCheckTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\quickedit\Tests\Access\EditEntityAccessCheckTest.
+ * Contains \Drupal\Tests\quickedit\Unit\Access\EditEntityAccessCheckTest.
  */
 
-namespace Drupal\quickedit\Tests\Access;
+namespace Drupal\Tests\quickedit\Unit\Access;
 
 use Symfony\Component\HttpFoundation\Request;
 use Drupal\Core\Access\AccessCheckInterface;
@@ -55,7 +55,7 @@ protected function setUp() {
   /**
    * Provides test data for testAccess().
    *
-   * @see \Drupal\quickedit\Tests\quickedit\Access\EditEntityAccessCheckTest::testAccess()
+   * @see \Drupal\Tests\quickedit\Unit\quickedit\Access\EditEntityAccessCheckTest::testAccess()
    */
   public function providerTestAccess() {
     $editable_entity = $this->getMockBuilder('Drupal\entity_test\Entity\EntityTest')
diff --git a/core/modules/quickedit/tests/src/Access/EditEntityFieldAccessCheckTest.php b/core/modules/quickedit/tests/src/Unit/Access/EditEntityFieldAccessCheckTest.php
similarity index 97%
rename from core/modules/quickedit/tests/src/Access/EditEntityFieldAccessCheckTest.php
rename to core/modules/quickedit/tests/src/Unit/Access/EditEntityFieldAccessCheckTest.php
index 5a97dd2..9669f79 100644
--- a/core/modules/quickedit/tests/src/Access/EditEntityFieldAccessCheckTest.php
+++ b/core/modules/quickedit/tests/src/Unit/Access/EditEntityFieldAccessCheckTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\quickedit\Tests\Access\EditEntityFieldAccessCheckTest.
+ * Contains \Drupal\Tests\quickedit\Unit\Access\EditEntityFieldAccessCheckTest.
  */
 
-namespace Drupal\quickedit\Tests\Access;
+namespace Drupal\Tests\quickedit\Unit\Access;
 
 use Symfony\Component\HttpFoundation\Request;
 use Drupal\Core\Access\AccessCheckInterface;
@@ -57,7 +57,7 @@ protected function setUp() {
   /**
    * Provides test data for testAccess().
    *
-   * @see \Drupal\edit\Tests\quickedit\Access\EditEntityFieldAccessCheckTest::testAccess()
+   * @see \Drupal\Tests\edit\Unit\quickedit\Access\EditEntityFieldAccessCheckTest::testAccess()
    */
   public function providerTestAccess() {
     $editable_entity = $this->createMockEntity();
diff --git a/core/modules/rdf/tests/src/RdfMappingConfigEntityUnitTest.php b/core/modules/rdf/tests/src/Unit/RdfMappingConfigEntityUnitTest.php
similarity index 98%
rename from core/modules/rdf/tests/src/RdfMappingConfigEntityUnitTest.php
rename to core/modules/rdf/tests/src/Unit/RdfMappingConfigEntityUnitTest.php
index c3e1e04..9420d65 100644
--- a/core/modules/rdf/tests/src/RdfMappingConfigEntityUnitTest.php
+++ b/core/modules/rdf/tests/src/Unit/RdfMappingConfigEntityUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\rdf\Tests\RdfMappingConfigEntityUnitTest.
+ * Contains \Drupal\Tests\rdf\Unit\RdfMappingConfigEntityUnitTest.
  */
 
-namespace Drupal\rdf\Tests;
+namespace Drupal\Tests\rdf\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/responsive_image/tests/src/ResponsiveImageMappingEntityTest.php b/core/modules/responsive_image/tests/src/Unit/ResponsiveImageMappingEntityTest.php
similarity index 96%
rename from core/modules/responsive_image/tests/src/ResponsiveImageMappingEntityTest.php
rename to core/modules/responsive_image/tests/src/Unit/ResponsiveImageMappingEntityTest.php
index 78303f6..e4e2e4e 100644
--- a/core/modules/responsive_image/tests/src/ResponsiveImageMappingEntityTest.php
+++ b/core/modules/responsive_image/tests/src/Unit/ResponsiveImageMappingEntityTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\responsive_image\Tests\ResponsiveImageMappingEntityTest.
+ * Contains \Drupal\Tests\responsive_image\Unit\ResponsiveImageMappingEntityTest.
  */
 
-namespace Drupal\responsive_image\Tests;
+namespace Drupal\Tests\responsive_image\Unit;
 
 use Drupal\responsive_image\Entity\ResponsiveImageMapping;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/rest/tests/src/CollectRoutesTest.php b/core/modules/rest/tests/src/Unit/CollectRoutesTest.php
similarity index 98%
rename from core/modules/rest/tests/src/CollectRoutesTest.php
rename to core/modules/rest/tests/src/Unit/CollectRoutesTest.php
index 3764b88..7a91831 100644
--- a/core/modules/rest/tests/src/CollectRoutesTest.php
+++ b/core/modules/rest/tests/src/Unit/CollectRoutesTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\rest\Tests\CollectRoutesTest.
+ * Contains \Drupal\Tests\rest\Unit\CollectRoutesTest.
  */
 
-namespace Drupal\rest\Tests;
+namespace Drupal\Tests\rest\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/search/tests/src/SearchPageRepositoryTest.php b/core/modules/search/tests/src/Unit/SearchPageRepositoryTest.php
similarity index 98%
rename from core/modules/search/tests/src/SearchPageRepositoryTest.php
rename to core/modules/search/tests/src/Unit/SearchPageRepositoryTest.php
index 0b01a8f..3ff112e 100644
--- a/core/modules/search/tests/src/SearchPageRepositoryTest.php
+++ b/core/modules/search/tests/src/Unit/SearchPageRepositoryTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\search\Tests\SearchPageRepositoryTest.
+ * Contains \Drupal\Tests\search\Unit\SearchPageRepositoryTest.
  */
 
-namespace Drupal\search\Tests;
+namespace Drupal\Tests\search\Unit;
 
 use Drupal\search\Entity\SearchPage;
 use Drupal\search\SearchPageRepository;
@@ -251,7 +251,7 @@ public function testSortSearchPages() {
     $entity_type = $this->getMock('Drupal\Core\Entity\EntityTypeInterface');
     $entity_type->expects($this->any())
       ->method('getClass')
-      ->will($this->returnValue('Drupal\search\Tests\TestSearchPage'));
+      ->will($this->returnValue('Drupal\Tests\search\Unit\TestSearchPage'));
     $this->storage->expects($this->once())
       ->method('getEntityType')
       ->will($this->returnValue($entity_type));
diff --git a/core/modules/search/tests/src/SearchPluginBagTest.php b/core/modules/search/tests/src/Unit/SearchPluginBagTest.php
similarity index 95%
rename from core/modules/search/tests/src/SearchPluginBagTest.php
rename to core/modules/search/tests/src/Unit/SearchPluginBagTest.php
index 3ac5c42..3ae6920 100644
--- a/core/modules/search/tests/src/SearchPluginBagTest.php
+++ b/core/modules/search/tests/src/Unit/SearchPluginBagTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\search\Tests\SearchPluginBagTest.
+ * Contains \Drupal\Tests\search\Unit\SearchPluginBagTest.
  */
 
-namespace Drupal\search\Tests;
+namespace Drupal\Tests\search\Unit;
 
 use Drupal\search\Plugin\SearchPluginBag;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/Encoder/JsonEncoderTest.php b/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
similarity index 82%
rename from core/modules/serialization/tests/src/Encoder/JsonEncoderTest.php
rename to core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
index 7878dc3..2ba8680 100644
--- a/core/modules/serialization/tests/src/Encoder/JsonEncoderTest.php
+++ b/core/modules/serialization/tests/src/Unit/Encoder/JsonEncoderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Encoder\JsonEncoderTest.
+ * Contains \Drupal\Tests\serialization\Unit\Encoder\JsonEncoderTest.
  */
 
-namespace Drupal\serialization\Tests\Encoder;
+namespace Drupal\Tests\serialization\Unit\Encoder;
 
 use Drupal\serialization\Encoder\JsonEncoder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/Encoder/XmlEncoderTest.php b/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
similarity index 95%
rename from core/modules/serialization/tests/src/Encoder/XmlEncoderTest.php
rename to core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
index ca38b35..c48a3ec 100644
--- a/core/modules/serialization/tests/src/Encoder/XmlEncoderTest.php
+++ b/core/modules/serialization/tests/src/Unit/Encoder/XmlEncoderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Encoder\XmlEncoderTest.
+ * Contains \Drupal\Tests\serialization\Unit\Encoder\XmlEncoderTest.
  */
 
-namespace Drupal\serialization\Tests\Encoder;
+namespace Drupal\Tests\serialization\Unit\Encoder;
 
 use Drupal\serialization\Encoder\XmlEncoder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/EntityResolver/ChainEntityResolverTest.php b/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
similarity index 96%
rename from core/modules/serialization/tests/src/EntityResolver/ChainEntityResolverTest.php
rename to core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
index db1ffb3..64d8ca6 100644
--- a/core/modules/serialization/tests/src/EntityResolver/ChainEntityResolverTest.php
+++ b/core/modules/serialization/tests/src/Unit/EntityResolver/ChainEntityResolverTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\EntityResolver\ChainEntityResolverTest.
+ * Contains \Drupal\Tests\serialization\Unit\EntityResolver\ChainEntityResolverTest.
  */
 
-namespace Drupal\serialization\Tests\EntityResolver;
+namespace Drupal\Tests\serialization\Unit\EntityResolver;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\serialization\EntityResolver\ChainEntityResolver;
diff --git a/core/modules/serialization/tests/src/EntityResolver/UuidResolverTest.php b/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
similarity index 95%
rename from core/modules/serialization/tests/src/EntityResolver/UuidResolverTest.php
rename to core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
index 4457fb1..940c1bdc 100644
--- a/core/modules/serialization/tests/src/EntityResolver/UuidResolverTest.php
+++ b/core/modules/serialization/tests/src/Unit/EntityResolver/UuidResolverTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\EntityResolver\UuidResolverTest.
+ * Contains \Drupal\Tests\serialization\Unit\EntityResolver\UuidResolverTest.
  */
 
-namespace Drupal\serialization\Tests\EntityResolver;
+namespace Drupal\Tests\serialization\Unit\EntityResolver;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\serialization\EntityResolver\UuidResolver;
diff --git a/core/modules/serialization/tests/src/Normalizer/ConfigEntityNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
similarity index 86%
rename from core/modules/serialization/tests/src/Normalizer/ConfigEntityNormalizerTest.php
rename to core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
index 9670cc1..466caf5 100644
--- a/core/modules/serialization/tests/src/Normalizer/ConfigEntityNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ConfigEntityNormalizerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Normalizer\ConfigEntityNormalizerTest.
+ * Contains \Drupal\Tests\serialization\Unit\Normalizer\ConfigEntityNormalizerTest.
  */
 
-namespace Drupal\serialization\Tests\Normalizer;
+namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\serialization\Normalizer\ConfigEntityNormalizer;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/Normalizer/EntityNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
similarity index 97%
rename from core/modules/serialization/tests/src/Normalizer/EntityNormalizerTest.php
rename to core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
index 4d6a409..c9eaa9a 100644
--- a/core/modules/serialization/tests/src/Normalizer/EntityNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/EntityNormalizerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Normalizer\EntityNormalizerTest.
+ * Contains \Drupal\Tests\serialization\Unit\Normalizer\EntityNormalizerTest.
  */
 
-namespace Drupal\serialization\Tests\Normalizer;
+namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\serialization\Normalizer\EntityNormalizer;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/Normalizer/ListNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
similarity index 95%
rename from core/modules/serialization/tests/src/Normalizer/ListNormalizerTest.php
rename to core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
index 9a3f630..e5ea66b 100644
--- a/core/modules/serialization/tests/src/Normalizer/ListNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/ListNormalizerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Normalizer\ListNormalizerTest.
+ * Contains \Drupal\Tests\serialization\Unit\Normalizer\ListNormalizerTest.
  */
 
-namespace Drupal\serialization\Tests\Normalizer;
+namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/serialization/tests/src/Normalizer/NormalizerBaseTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
similarity index 89%
rename from core/modules/serialization/tests/src/Normalizer/NormalizerBaseTest.php
rename to core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
index dbb67d9..e77882a 100644
--- a/core/modules/serialization/tests/src/Normalizer/NormalizerBaseTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Normalizer\NormalizerBaseTest.
+ * Contains \Drupal\Tests\serialization\Unit\Normalizer\NormalizerBaseTest.
  */
 
-namespace Drupal\serialization\Tests\Normalizer;
+namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\serialization\Normalizer\NormalizerBase;
@@ -29,7 +29,7 @@ class NormalizerBaseTest extends UnitTestCase {
    *   (optional) the supported interface or class to set on the normalizer.
    */
   public function testSupportsNormalization($expected_return, $data, $supported_interface_or_class = NULL) {
-    $normalizer_base = $this->getMockForAbstractClass('Drupal\serialization\Tests\Normalizer\TestNormalizerBase');
+    $normalizer_base = $this->getMockForAbstractClass('Drupal\Tests\serialization\Unit\Normalizer\TestNormalizerBase');
 
     if (isset($supported_interface_or_class)) {
       $normalizer_base->setSupportedInterfaceOrClass($supported_interface_or_class);
diff --git a/core/modules/serialization/tests/src/Normalizer/TypedDataNormalizerTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
similarity index 91%
rename from core/modules/serialization/tests/src/Normalizer/TypedDataNormalizerTest.php
rename to core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
index fb7d085..4d285a5 100644
--- a/core/modules/serialization/tests/src/Normalizer/TypedDataNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/TypedDataNormalizerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\serialization\Tests\Normalizer\TypedDataNormalizerTest
+ * Contains \Drupal\Tests\serialization\Unit\Normalizer\TypedDataNormalizerTest
  */
 
-namespace Drupal\serialization\Tests\Normalizer;
+namespace Drupal\Tests\serialization\Unit\Normalizer;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\serialization\Normalizer\TypedDataNormalizer;
diff --git a/core/modules/shortcut/tests/src/Menu/ShortcutLocalTasksTest.php b/core/modules/shortcut/tests/src/Unit/Menu/ShortcutLocalTasksTest.php
similarity index 89%
rename from core/modules/shortcut/tests/src/Menu/ShortcutLocalTasksTest.php
rename to core/modules/shortcut/tests/src/Unit/Menu/ShortcutLocalTasksTest.php
index 0bb3630..526b680 100644
--- a/core/modules/shortcut/tests/src/Menu/ShortcutLocalTasksTest.php
+++ b/core/modules/shortcut/tests/src/Unit/Menu/ShortcutLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\shortcut\Tests\Menu\ShortcutLocalTasksTest.
+ * Contains \Drupal\Tests\shortcut\Unit\Menu\ShortcutLocalTasksTest.
  */
 
-namespace Drupal\shortcut\Tests\Menu;
+namespace Drupal\Tests\shortcut\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/simpletest/src/TestDiscovery.php b/core/modules/simpletest/src/TestDiscovery.php
index 144e2a4..26b598f 100644
--- a/core/modules/simpletest/src/TestDiscovery.php
+++ b/core/modules/simpletest/src/TestDiscovery.php
@@ -81,20 +81,17 @@ public function registerTestNamespaces() {
     foreach ($this->getExtensions() as $name => $extension) {
       $this->availableExtensions[$extension->getType()][$name] = $name;
 
-      $base_namespace = "Drupal\\$name\\";
       $base_path = DRUPAL_ROOT . '/' . $extension->getPath();
 
       // Add namespace of disabled/uninstalled extensions.
-      if (!isset($existing[$base_namespace])) {
-        $this->classLoader->addPsr4($base_namespace, "$base_path/src");
+      if (!isset($existing["Drupal\\$name\\"])) {
+        $this->classLoader->addPsr4("Drupal\\$name\\", "$base_path/src");
       }
       // Add Simpletest test namespace.
-      $this->testNamespaces[$base_namespace . 'Tests\\'][] = "$base_path/src/Tests";
+      $this->testNamespaces["Drupal\\$name\\Tests\\"][] = "$base_path/src/Tests";
 
       // Add PHPUnit test namespace.
-      // @todo Move PHPUnit namespace of extensions into Drupal\Tests\$name.
-      // @see https://www.drupal.org/node/2260121
-      $this->testNamespaces[$base_namespace . 'Tests\\'][] = "$base_path/tests/src";
+      $this->testNamespaces["Drupal\\Tests\\$name\\"][] = "$base_path/tests/src";
     }
 
     foreach ($this->testNamespaces as $prefix => $paths) {
diff --git a/core/modules/simpletest/tests/src/phpunit_error.xml b/core/modules/simpletest/tests/fixtures/phpunit_error.xml
similarity index 100%
rename from core/modules/simpletest/tests/src/phpunit_error.xml
rename to core/modules/simpletest/tests/fixtures/phpunit_error.xml
diff --git a/core/modules/simpletest/tests/src/Fixtures/select_2nd_selected.html b/core/modules/simpletest/tests/fixtures/select_2nd_selected.html
similarity index 100%
rename from core/modules/simpletest/tests/src/Fixtures/select_2nd_selected.html
rename to core/modules/simpletest/tests/fixtures/select_2nd_selected.html
diff --git a/core/modules/simpletest/tests/src/Fixtures/select_none_selected.html b/core/modules/simpletest/tests/fixtures/select_none_selected.html
similarity index 100%
rename from core/modules/simpletest/tests/src/Fixtures/select_none_selected.html
rename to core/modules/simpletest/tests/fixtures/select_none_selected.html
diff --git a/core/modules/simpletest/tests/src/PhpUnitAutoloaderTest.php b/core/modules/simpletest/tests/src/Unit/PhpUnitAutoloaderTest.php
similarity index 82%
rename from core/modules/simpletest/tests/src/PhpUnitAutoloaderTest.php
rename to core/modules/simpletest/tests/src/Unit/PhpUnitAutoloaderTest.php
index 3f1fa37..bd18b90 100644
--- a/core/modules/simpletest/tests/src/PhpUnitAutoloaderTest.php
+++ b/core/modules/simpletest/tests/src/Unit/PhpUnitAutoloaderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\simpletest\Tests\PhpUnitAutoloaderTest.
+ * Contains \Drupal\Tests\simpletest\Unit\PhpUnitAutoloaderTest.
  */
 
-namespace Drupal\simpletest\Tests;
+namespace Drupal\Tests\simpletest\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/simpletest/tests/src/PhpUnitErrorTest.php b/core/modules/simpletest/tests/src/Unit/PhpUnitErrorTest.php
similarity index 69%
rename from core/modules/simpletest/tests/src/PhpUnitErrorTest.php
rename to core/modules/simpletest/tests/src/Unit/PhpUnitErrorTest.php
index 4139859..f46f5f0 100644
--- a/core/modules/simpletest/tests/src/PhpUnitErrorTest.php
+++ b/core/modules/simpletest/tests/src/Unit/PhpUnitErrorTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\simpletest\Tests;
+namespace Drupal\Tests\simpletest\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
@@ -17,15 +17,10 @@ class PhpUnitErrorTest extends UnitTestCase {
    * @covers ::simpletest_phpunit_xml_to_rows
    */
   public function testPhpUnitXmlParsing() {
-    // This test class could be either in tests/Drupal/simpletest/Tests/, or in
-    // tests/src/, after the PSR-4 transition.
-    if (file_exists(__DIR__ . '/../../simpletest.module')) {
-      require_once __DIR__ . '/../../simpletest.module';
-    }
-    else {
-      require_once __DIR__ . '/../../../../simpletest.module';
-    }
-    $phpunit_error_xml = __DIR__ . '/phpunit_error.xml';
+    require_once DRUPAL_ROOT . '/core/modules/simpletest/simpletest.module';
+
+    $phpunit_error_xml = DRUPAL_ROOT . '/core/modules/simpletest/tests/fixtures/phpunit_error.xml';
+
     $res = simpletest_phpunit_xml_to_rows(1, $phpunit_error_xml);
     $this->assertEquals(count($res), 4, 'All testcases got extracted');
     $this->assertNotEquals($res[0]['status'], 'pass');
diff --git a/core/modules/simpletest/tests/src/TestBaseTest.php b/core/modules/simpletest/tests/src/Unit/TestBaseTest.php
similarity index 97%
rename from core/modules/simpletest/tests/src/TestBaseTest.php
rename to core/modules/simpletest/tests/src/Unit/TestBaseTest.php
index 50e08b5..bce3a83 100644
--- a/core/modules/simpletest/tests/src/TestBaseTest.php
+++ b/core/modules/simpletest/tests/src/Unit/TestBaseTest.php
@@ -5,7 +5,7 @@
  * Contains \Drupal\simpletest\TestBaseTest.
  */
 
-namespace Drupal\simpletest\Tests;
+namespace Drupal\Tests\simpletest\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/simpletest/tests/src/WebTestBaseTest.php b/core/modules/simpletest/tests/src/Unit/WebTestBaseTest.php
similarity index 96%
rename from core/modules/simpletest/tests/src/WebTestBaseTest.php
rename to core/modules/simpletest/tests/src/Unit/WebTestBaseTest.php
index 0c2cb1c..c1c2a0d 100644
--- a/core/modules/simpletest/tests/src/WebTestBaseTest.php
+++ b/core/modules/simpletest/tests/src/Unit/WebTestBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\simpletest\Tests\WebTestBaseTest.
+ * Contains \Drupal\Tests\simpletest\Unit\WebTestBaseTest.
  */
 
-namespace Drupal\simpletest\Tests;
+namespace Drupal\Tests\simpletest\Unit;
 
 use Drupal\Tests\UnitTestCase;
 
@@ -50,7 +50,7 @@ public function providerAssertFieldByName() {
    * @covers ::assertFieldByName
    */
   public function testAssertFieldByName($filename, $name, $value, $expected) {
-    $content = file_get_contents(__DIR__ . '/Fixtures/' . $filename . '.html');
+    $content = file_get_contents(DRUPAL_ROOT . '/core/modules/simpletest/tests/fixtures/' . $filename . '.html');
 
     $web_test = $this->getMockBuilder('Drupal\simpletest\WebTestBase')
       ->disableOriginalConstructor()
diff --git a/core/modules/system/tests/src/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php b/core/modules/system/tests/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
similarity index 98%
rename from core/modules/system/tests/src/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
rename to core/modules/system/tests/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
index 1b521ca..37578b7 100644
--- a/core/modules/system/tests/src/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
+++ b/core/modules/system/tests/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\Breadcrumbs\PathBasedBreadcrumbBuilderTest
+ * Contains \Drupal\Tests\system\Unit\Breadcrumbs\PathBasedBreadcrumbBuilderTest
  */
 
-namespace Drupal\system\Tests\Breadcrumbs;
+namespace Drupal\Tests\system\Unit\Breadcrumbs;
 
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\StringTranslation\TranslationInterface;
@@ -273,7 +273,7 @@ public function testBuildWithException($exception_class, $exception_argument) {
    * @return array
    *   The list of exception test cases.
    *
-   * @see \Drupal\system\Tests\Breadcrumbs\PathBasedBreadcrumbBuilderTest::testBuildWithException()
+   * @see \Drupal\Tests\system\Unit\Breadcrumbs\PathBasedBreadcrumbBuilderTest::testBuildWithException()
    */
   public function providerTestBuildWithException() {
     return array(
diff --git a/core/modules/system/tests/src/Controller/SystemControllerTest.php b/core/modules/system/tests/src/Unit/Controller/SystemControllerTest.php
similarity index 99%
rename from core/modules/system/tests/src/Controller/SystemControllerTest.php
rename to core/modules/system/tests/src/Unit/Controller/SystemControllerTest.php
index f4b469e..e5ec1da 100644
--- a/core/modules/system/tests/src/Controller/SystemControllerTest.php
+++ b/core/modules/system/tests/src/Unit/Controller/SystemControllerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\Controller\SystemControllerTest.
+ * Contains \Drupal\Tests\system\Unit\Controller\SystemControllerTest.
  */
 
-namespace Drupal\system\Tests\Controller;
+namespace Drupal\Tests\system\Unit\Controller;
 
 use Drupal\Component\Serialization\Json;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/core/modules/system/tests/src/Menu/SystemLocalTasksTest.php b/core/modules/system/tests/src/Unit/Menu/SystemLocalTasksTest.php
similarity index 94%
rename from core/modules/system/tests/src/Menu/SystemLocalTasksTest.php
rename to core/modules/system/tests/src/Unit/Menu/SystemLocalTasksTest.php
index 11a0851..6d98ebd 100644
--- a/core/modules/system/tests/src/Menu/SystemLocalTasksTest.php
+++ b/core/modules/system/tests/src/Unit/Menu/SystemLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\Menu\SystemLocalTasksTest.
+ * Contains \Drupal\Tests\system\Unit\Menu\SystemLocalTasksTest.
  */
 
-namespace Drupal\system\Tests\Menu;
+namespace Drupal\Tests\system\Unit\Menu;
 
 use Drupal\Core\Extension\Extension;
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
diff --git a/core/modules/system/tests/src/Transliteration/MachineNameControllerTest.php b/core/modules/system/tests/src/Unit/Transliteration/MachineNameControllerTest.php
similarity index 94%
rename from core/modules/system/tests/src/Transliteration/MachineNameControllerTest.php
rename to core/modules/system/tests/src/Unit/Transliteration/MachineNameControllerTest.php
index 200cfc5..e77dcd5 100644
--- a/core/modules/system/tests/src/Transliteration/MachineNameControllerTest.php
+++ b/core/modules/system/tests/src/Unit/Transliteration/MachineNameControllerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\Transliteration\MachineNameControllerTest.
+ * Contains \Drupal\Tests\system\Unit\Transliteration\MachineNameControllerTest.
  */
 
-namespace Drupal\system\Tests\Transliteration;
+namespace Drupal\Tests\system\Unit\Transliteration;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\Component\Transliteration\PHPTransliteration;
diff --git a/core/modules/taxonomy/tests/src/Menu/TaxonomyLocalTasksTest.php b/core/modules/taxonomy/tests/src/Unit/Menu/TaxonomyLocalTasksTest.php
similarity index 89%
rename from core/modules/taxonomy/tests/src/Menu/TaxonomyLocalTasksTest.php
rename to core/modules/taxonomy/tests/src/Unit/Menu/TaxonomyLocalTasksTest.php
index b2d40ea..be3dd53 100644
--- a/core/modules/taxonomy/tests/src/Menu/TaxonomyLocalTasksTest.php
+++ b/core/modules/taxonomy/tests/src/Unit/Menu/TaxonomyLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\taxonomy\Tests\Menu\TaxonomyLocalTasksTest.
+ * Contains \Drupal\Tests\taxonomy\Unit\Menu\TaxonomyLocalTasksTest.
  */
 
-namespace Drupal\taxonomy\Tests\Menu;
+namespace Drupal\Tests\taxonomy\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/tour/tests/src/Entity/TourTest.php b/core/modules/tour/tests/src/Unit/Entity/TourTest.php
similarity index 97%
rename from core/modules/tour/tests/src/Entity/TourTest.php
rename to core/modules/tour/tests/src/Unit/Entity/TourTest.php
index 7b5f943..b021ab8 100644
--- a/core/modules/tour/tests/src/Entity/TourTest.php
+++ b/core/modules/tour/tests/src/Unit/Entity/TourTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Contains \Drupal\tour\Tests\Entity\TourTest.
+ * Contains \Drupal\Tests\tour\Unit\Entity\TourTest.
  */
 
-namespace Drupal\tour\Tests\Entity;
+namespace Drupal\Tests\tour\Unit\Entity;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/update/tests/src/UpdateFetcherTest.php b/core/modules/update/tests/src/Unit/UpdateFetcherTest.php
similarity index 97%
rename from core/modules/update/tests/src/UpdateFetcherTest.php
rename to core/modules/update/tests/src/Unit/UpdateFetcherTest.php
index 792f776..56c61aa 100644
--- a/core/modules/update/tests/src/UpdateFetcherTest.php
+++ b/core/modules/update/tests/src/Unit/UpdateFetcherTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\update\Tests\UpdateFetcherTest.
+ * Contains \Drupal\Tests\update\Unit\UpdateFetcherTest.
  */
 
-namespace Drupal\update\Tests;
+namespace Drupal\Tests\update\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\update\UpdateFetcher;
diff --git a/core/modules/user/tests/src/Menu/UserLocalTasksTest.php b/core/modules/user/tests/src/Unit/Menu/UserLocalTasksTest.php
similarity index 95%
rename from core/modules/user/tests/src/Menu/UserLocalTasksTest.php
rename to core/modules/user/tests/src/Unit/Menu/UserLocalTasksTest.php
index a6cc6f2..b58f86b 100644
--- a/core/modules/user/tests/src/Menu/UserLocalTasksTest.php
+++ b/core/modules/user/tests/src/Unit/Menu/UserLocalTasksTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Menu\UserLocalTasksTest.
+ * Contains \Drupal\Tests\user\Unit\Menu\UserLocalTasksTest.
  */
 
-namespace Drupal\user\Tests\Menu;
+namespace Drupal\Tests\user\Unit\Menu;
 
 use Drupal\Tests\Core\Menu\LocalTaskIntegrationTest;
 
diff --git a/core/modules/user/tests/src/PermissionsHashTest.php b/core/modules/user/tests/src/Unit/PermissionsHashTest.php
similarity index 98%
rename from core/modules/user/tests/src/PermissionsHashTest.php
rename to core/modules/user/tests/src/Unit/PermissionsHashTest.php
index 6332f3d..2579682 100644
--- a/core/modules/user/tests/src/PermissionsHashTest.php
+++ b/core/modules/user/tests/src/Unit/PermissionsHashTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\PermissionsHashTest.
+ * Contains \Drupal\Tests\user\Unit\PermissionsHashTest.
  */
 
-namespace Drupal\user\Tests {
+namespace Drupal\Tests\user\Unit {
 
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Site\Settings;
diff --git a/core/modules/user/tests/src/Plugin/Action/AddRoleUserTest.php b/core/modules/user/tests/src/Unit/Plugin/Action/AddRoleUserTest.php
similarity index 92%
rename from core/modules/user/tests/src/Plugin/Action/AddRoleUserTest.php
rename to core/modules/user/tests/src/Unit/Plugin/Action/AddRoleUserTest.php
index 0c9879e..a2f9e9c 100644
--- a/core/modules/user/tests/src/Plugin/Action/AddRoleUserTest.php
+++ b/core/modules/user/tests/src/Unit/Plugin/Action/AddRoleUserTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Plugin\Action\AddRoleUserTest.
+ * Contains \Drupal\Tests\user\Unit\Plugin\Action\AddRoleUserTest.
  */
 
-namespace Drupal\user\Tests\Plugin\Action;
+namespace Drupal\Tests\user\Unit\Plugin\Action;
 
 use Drupal\user\Plugin\Action\AddRoleUser;
 
diff --git a/core/modules/user/tests/src/Plugin/Action/RemoveRoleUserTest.php b/core/modules/user/tests/src/Unit/Plugin/Action/RemoveRoleUserTest.php
similarity index 92%
rename from core/modules/user/tests/src/Plugin/Action/RemoveRoleUserTest.php
rename to core/modules/user/tests/src/Unit/Plugin/Action/RemoveRoleUserTest.php
index 87f7212..e294398 100644
--- a/core/modules/user/tests/src/Plugin/Action/RemoveRoleUserTest.php
+++ b/core/modules/user/tests/src/Unit/Plugin/Action/RemoveRoleUserTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Plugin\Action\RemoveRoleUserTest.
+ * Contains \Drupal\Tests\user\Unit\Plugin\Action\RemoveRoleUserTest.
  */
 
-namespace Drupal\user\Tests\Plugin\Action;
+namespace Drupal\Tests\user\Unit\Plugin\Action;
 
 use Drupal\user\Plugin\Action\RemoveRoleUser;
 
diff --git a/core/modules/user/tests/src/Plugin/Action/RoleUserTestBase.php b/core/modules/user/tests/src/Unit/Plugin/Action/RoleUserTestBase.php
similarity index 87%
rename from core/modules/user/tests/src/Plugin/Action/RoleUserTestBase.php
rename to core/modules/user/tests/src/Unit/Plugin/Action/RoleUserTestBase.php
index 54c8fa0..5f7ff13 100644
--- a/core/modules/user/tests/src/Plugin/Action/RoleUserTestBase.php
+++ b/core/modules/user/tests/src/Unit/Plugin/Action/RoleUserTestBase.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Plugin\Action\RoleUserTestBase.
+ * Contains \Drupal\Tests\user\Unit\Plugin\Action\RoleUserTestBase.
  */
 
-namespace Drupal\user\Tests\Plugin\Action;
+namespace Drupal\Tests\user\Unit\Plugin\Action;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/user/tests/src/Plugin/Core/Entity/UserTest.php b/core/modules/user/tests/src/Unit/Plugin/Core/Entity/UserTest.php
similarity index 94%
rename from core/modules/user/tests/src/Plugin/Core/Entity/UserTest.php
rename to core/modules/user/tests/src/Unit/Plugin/Core/Entity/UserTest.php
index 19d7f2b..45b490e 100644
--- a/core/modules/user/tests/src/Plugin/Core/Entity/UserTest.php
+++ b/core/modules/user/tests/src/Unit/Plugin/Core/Entity/UserTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Plugin\Core\Entity\UserTest.
+ * Contains \Drupal\Tests\user\Unit\Plugin\Core\Entity\UserTest.
  */
 
-namespace Drupal\user\Tests\Plugin\Core\Entity {
+namespace Drupal\Tests\user\Unit\Plugin\Core\Entity {
 
 use Drupal\Tests\Core\Session\UserSessionTest;
 use Drupal\user\Entity\User;
diff --git a/core/modules/user/tests/src/Plugin/views/field/UserBulkFormTest.php b/core/modules/user/tests/src/Unit/Plugin/views/field/UserBulkFormTest.php
similarity index 95%
rename from core/modules/user/tests/src/Plugin/views/field/UserBulkFormTest.php
rename to core/modules/user/tests/src/Unit/Plugin/views/field/UserBulkFormTest.php
index e6dbe9b..0e0b44e 100644
--- a/core/modules/user/tests/src/Plugin/views/field/UserBulkFormTest.php
+++ b/core/modules/user/tests/src/Unit/Plugin/views/field/UserBulkFormTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Plugin\views\field\UserBulkFormTest.
+ * Contains \Drupal\Tests\user\Unit\Plugin\views\field\UserBulkFormTest.
  */
 
-namespace Drupal\user\Tests\Plugin\views\field;
+namespace Drupal\Tests\user\Unit\Plugin\views\field;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/user/tests/src/TempStoreTest.php b/core/modules/user/tests/src/Unit/TempStoreTest.php
similarity index 99%
rename from core/modules/user/tests/src/TempStoreTest.php
rename to core/modules/user/tests/src/Unit/TempStoreTest.php
index 97bd410..959df5c 100644
--- a/core/modules/user/tests/src/TempStoreTest.php
+++ b/core/modules/user/tests/src/Unit/TempStoreTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\TempStoreTest.
+ * Contains \Drupal\Tests\user\Unit\TempStoreTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\user\TempStore;
diff --git a/core/modules/user/tests/src/UserAuthTest.php b/core/modules/user/tests/src/Unit/UserAuthTest.php
similarity index 98%
rename from core/modules/user/tests/src/UserAuthTest.php
rename to core/modules/user/tests/src/Unit/UserAuthTest.php
index 03391b5..d70824d 100644
--- a/core/modules/user/tests/src/UserAuthTest.php
+++ b/core/modules/user/tests/src/Unit/UserAuthTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\UserAuthTest.
+ * Contains \Drupal\Tests\user\Unit\UserAuthTest.
  */
 
-namespace Drupal\user\Tests;
+namespace Drupal\Tests\user\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\user\UserAuth;
diff --git a/core/modules/user/tests/src/Views/Argument/RolesRidTest.php b/core/modules/user/tests/src/Unit/Views/Argument/RolesRidTest.php
similarity index 96%
rename from core/modules/user/tests/src/Views/Argument/RolesRidTest.php
rename to core/modules/user/tests/src/Unit/Views/Argument/RolesRidTest.php
index f90a84c..4e85059 100644
--- a/core/modules/user/tests/src/Views/Argument/RolesRidTest.php
+++ b/core/modules/user/tests/src/Unit/Views/Argument/RolesRidTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\user\Tests\Views\Argument\RolesRidTest.
+ * Contains \Drupal\Tests\user\Unit\Views\Argument\RolesRidTest.
  */
 
-namespace Drupal\user\Tests\Views\Argument;
+namespace Drupal\Tests\user\Unit\Views\Argument;
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
diff --git a/core/modules/views/tests/src/Controller/ViewAjaxControllerTest.php b/core/modules/views/tests/src/Unit/Controller/ViewAjaxControllerTest.php
similarity index 98%
rename from core/modules/views/tests/src/Controller/ViewAjaxControllerTest.php
rename to core/modules/views/tests/src/Unit/Controller/ViewAjaxControllerTest.php
index b977412..b3a7d9a 100644
--- a/core/modules/views/tests/src/Controller/ViewAjaxControllerTest.php
+++ b/core/modules/views/tests/src/Unit/Controller/ViewAjaxControllerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Controller\ViewAjaxControllerTest.
+ * Contains \Drupal\Tests\views\Unit\Controller\ViewAjaxControllerTest.
  */
 
-namespace Drupal\views\Tests\Controller {
+namespace Drupal\Tests\views\Unit\Controller {
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Ajax\ViewAjaxResponse;
diff --git a/core/modules/views/tests/src/Entity/ViewTest.php b/core/modules/views/tests/src/Unit/Entity/ViewTest.php
similarity index 96%
rename from core/modules/views/tests/src/Entity/ViewTest.php
rename to core/modules/views/tests/src/Unit/Entity/ViewTest.php
index 6bfdd5b..8af4e6d 100644
--- a/core/modules/views/tests/src/Entity/ViewTest.php
+++ b/core/modules/views/tests/src/Unit/Entity/ViewTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Entity\ViewTest.
+ * Contains \Drupal\Tests\views\Unit\Entity\ViewTest.
  */
 
-namespace Drupal\views\Tests\Entity {
+namespace Drupal\Tests\views\Unit\Entity {
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Entity\EntityType;
diff --git a/core/modules/views/tests/src/EventSubscriber/RouteSubscriberTest.php b/core/modules/views/tests/src/Unit/EventSubscriber/RouteSubscriberTest.php
similarity index 97%
rename from core/modules/views/tests/src/EventSubscriber/RouteSubscriberTest.php
rename to core/modules/views/tests/src/Unit/EventSubscriber/RouteSubscriberTest.php
index e27a5fe..e48c311 100644
--- a/core/modules/views/tests/src/EventSubscriber/RouteSubscriberTest.php
+++ b/core/modules/views/tests/src/Unit/EventSubscriber/RouteSubscriberTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\EventSubscriber\RouteSubscriberTest.
+ * Contains \Drupal\Tests\views\Unit\EventSubscriber\RouteSubscriberTest.
  */
 
-namespace Drupal\views\Tests\EventSubscriber;
+namespace Drupal\Tests\views\Unit\EventSubscriber;
 
 use Drupal\Core\Routing\RouteBuildEvent;
 use Drupal\Tests\UnitTestCase;
@@ -36,7 +36,7 @@ class RouteSubscriberTest extends UnitTestCase {
   /**
    * The tested views route subscriber.
    *
-   * @var \Drupal\views\EventSubscriber\RouteSubscriber|\Drupal\views\Tests\EventSubscriber\TestRouteSubscriber
+   * @var \Drupal\views\EventSubscriber\RouteSubscriber|\Drupal\Tests\views\Unit\EventSubscriber\TestRouteSubscriber
    */
   protected $routeSubscriber;
 
diff --git a/core/modules/views/tests/src/Plugin/Block/ViewsBlockTest.php b/core/modules/views/tests/src/Unit/Plugin/Block/ViewsBlockTest.php
similarity index 97%
rename from core/modules/views/tests/src/Plugin/Block/ViewsBlockTest.php
rename to core/modules/views/tests/src/Unit/Plugin/Block/ViewsBlockTest.php
index 80a80b9..3be1db9 100644
--- a/core/modules/views/tests/src/Plugin/Block/ViewsBlockTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/Block/ViewsBlockTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\Block\ViewsBlockTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\Block\ViewsBlockTest.
  */
 
-namespace Drupal\views\Tests\Plugin\Block {
+namespace Drupal\Tests\views\Unit\Plugin\Block {
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/views/tests/src/Plugin/Derivative/ViewsLocalTaskTest.php b/core/modules/views/tests/src/Unit/Plugin/Derivative/ViewsLocalTaskTest.php
similarity index 98%
rename from core/modules/views/tests/src/Plugin/Derivative/ViewsLocalTaskTest.php
rename to core/modules/views/tests/src/Unit/Plugin/Derivative/ViewsLocalTaskTest.php
index 1ed2a0d..c75d96f 100644
--- a/core/modules/views/tests/src/Plugin/Derivative/ViewsLocalTaskTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/Derivative/ViewsLocalTaskTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\Derivative\ViewsLocalTaskTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\Derivative\ViewsLocalTaskTest.
  */
 
-namespace Drupal\views\Tests\Plugin\Derivative;
+namespace Drupal\Tests\views\Unit\Plugin\Derivative;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Plugin\Derivative\ViewsLocalTask;
diff --git a/core/modules/views/tests/src/Plugin/area/MessagesTest.php b/core/modules/views/tests/src/Unit/Plugin/area/MessagesTest.php
similarity index 92%
rename from core/modules/views/tests/src/Plugin/area/MessagesTest.php
rename to core/modules/views/tests/src/Unit/Plugin/area/MessagesTest.php
index 2a48964..d9a3500 100644
--- a/core/modules/views/tests/src/Plugin/area/MessagesTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/area/MessagesTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\area\MessagesTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\area\MessagesTest.
  */
 
-namespace Drupal\views\Tests\Plugin\area;
+namespace Drupal\Tests\views\Unit\Plugin\area;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Plugin\views\area\Messages;
diff --git a/core/modules/views/tests/src/Plugin/area/ResultTest.php b/core/modules/views/tests/src/Unit/Plugin/area/ResultTest.php
similarity index 97%
rename from core/modules/views/tests/src/Plugin/area/ResultTest.php
rename to core/modules/views/tests/src/Unit/Plugin/area/ResultTest.php
index d7e1afb..651ef08 100644
--- a/core/modules/views/tests/src/Plugin/area/ResultTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/area/ResultTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\area\ResultTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\area\ResultTest.
  */
 
-namespace Drupal\views\Tests\Plugin\area;
+namespace Drupal\Tests\views\Unit\Plugin\area;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\ViewExecutable;
diff --git a/core/modules/views/tests/src/Plugin/argument_default/QueryParameterTest.php b/core/modules/views/tests/src/Unit/Plugin/argument_default/QueryParameterTest.php
similarity index 93%
rename from core/modules/views/tests/src/Plugin/argument_default/QueryParameterTest.php
rename to core/modules/views/tests/src/Unit/Plugin/argument_default/QueryParameterTest.php
index f402f67..a2e9c5c 100644
--- a/core/modules/views/tests/src/Plugin/argument_default/QueryParameterTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/argument_default/QueryParameterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\argument_default\QueryParameterTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\argument_default\QueryParameterTest.
  */
 
-namespace Drupal\views\Tests\Plugin\argument_default;
+namespace Drupal\Tests\views\Unit\Plugin\argument_default;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Plugin\views\argument_default\QueryParameter;
diff --git a/core/modules/views/tests/src/Plugin/argument_default/RawTest.php b/core/modules/views/tests/src/Unit/Plugin/argument_default/RawTest.php
similarity index 94%
rename from core/modules/views/tests/src/Plugin/argument_default/RawTest.php
rename to core/modules/views/tests/src/Unit/Plugin/argument_default/RawTest.php
index 5553f8e..2d1df0e 100644
--- a/core/modules/views/tests/src/Plugin/argument_default/RawTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/argument_default/RawTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\argument_default\RawTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\argument_default\RawTest.
  */
 
-namespace Drupal\views\Tests\Plugin\argument_default;
+namespace Drupal\Tests\views\Unit\Plugin\argument_default;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Plugin\views\argument_default\Raw;
diff --git a/core/modules/views/tests/src/Plugin/argument_validator/EntityTest.php b/core/modules/views/tests/src/Unit/Plugin/argument_validator/EntityTest.php
similarity index 97%
rename from core/modules/views/tests/src/Plugin/argument_validator/EntityTest.php
rename to core/modules/views/tests/src/Unit/Plugin/argument_validator/EntityTest.php
index f79edaa..8a27bcf 100644
--- a/core/modules/views/tests/src/Plugin/argument_validator/EntityTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/argument_validator/EntityTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\argument_validator\EntityTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\argument_validator\EntityTest.
  */
 
-namespace Drupal\views\Tests\Plugin\argument_validator;
+namespace Drupal\Tests\views\Unit\Plugin\argument_validator;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Plugin\views\argument_validator\Entity;
diff --git a/core/modules/views/tests/src/Plugin/display/PathPluginBaseTest.php b/core/modules/views/tests/src/Unit/Plugin/display/PathPluginBaseTest.php
similarity index 98%
rename from core/modules/views/tests/src/Plugin/display/PathPluginBaseTest.php
rename to core/modules/views/tests/src/Unit/Plugin/display/PathPluginBaseTest.php
index d81324a..a6d3fab 100644
--- a/core/modules/views/tests/src/Plugin/display/PathPluginBaseTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/display/PathPluginBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\display\PathPluginBaseTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\display\PathPluginBaseTest.
  */
 
-namespace Drupal\views\Tests\Plugin\display;
+namespace Drupal\Tests\views\Unit\Plugin\display;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/views/tests/src/Plugin/field/CounterTest.php b/core/modules/views/tests/src/Unit/Plugin/field/CounterTest.php
similarity index 98%
rename from core/modules/views/tests/src/Plugin/field/CounterTest.php
rename to core/modules/views/tests/src/Unit/Plugin/field/CounterTest.php
index 151b80e..1f9d010 100644
--- a/core/modules/views/tests/src/Plugin/field/CounterTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/field/CounterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\field\CounterTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\field\CounterTest.
  */
 
-namespace Drupal\views\Tests\Plugin\field;
+namespace Drupal\Tests\views\Unit\Plugin\field;
 
 use Drupal\Component\Utility\String;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/views/tests/src/Plugin/pager/PagerPluginBaseTest.php b/core/modules/views/tests/src/Unit/Plugin/pager/PagerPluginBaseTest.php
similarity index 95%
rename from core/modules/views/tests/src/Plugin/pager/PagerPluginBaseTest.php
rename to core/modules/views/tests/src/Unit/Plugin/pager/PagerPluginBaseTest.php
index 21e415f..a9a0f24 100644
--- a/core/modules/views/tests/src/Plugin/pager/PagerPluginBaseTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/pager/PagerPluginBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\pager\PagerPluginBaseTest
+ * Contains \Drupal\Tests\views\Unit\Plugin\pager\PagerPluginBaseTest
  */
 
-namespace Drupal\views\Tests\Plugin\pager;
+namespace Drupal\Tests\views\Unit\Plugin\pager;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\Core\Database\StatementInterface;
@@ -205,7 +205,7 @@ public function providerTestHasMoreRecords() {
    * @see \Drupal\views\Plugin\views\pager\PagerPluginBase::executeCountQuery()
    */
   public function testExecuteCountQueryWithoutOffset() {
-    $statement = $this->getMock('\Drupal\views\Tests\Plugin\pager\TestStatementInterface');
+    $statement = $this->getMock('\Drupal\Tests\views\Unit\Plugin\pager\TestStatementInterface');
 
     $statement->expects($this->once())
       ->method('fetchField')
@@ -229,7 +229,7 @@ public function testExecuteCountQueryWithoutOffset() {
    * @see \Drupal\views\Plugin\views\pager\PagerPluginBase::executeCountQuery()
    */
   public function testExecuteCountQueryWithOffset() {
-    $statement = $this->getMock('\Drupal\views\Tests\Plugin\pager\TestStatementInterface');
+    $statement = $this->getMock('\Drupal\Tests\views\Unit\Plugin\pager\TestStatementInterface');
 
     $statement->expects($this->once())
       ->method('fetchField')
diff --git a/core/modules/views/tests/src/Plugin/views/display/BlockTest.php b/core/modules/views/tests/src/Unit/Plugin/views/display/BlockTest.php
similarity index 94%
rename from core/modules/views/tests/src/Plugin/views/display/BlockTest.php
rename to core/modules/views/tests/src/Unit/Plugin/views/display/BlockTest.php
index 6d31174..c51e3a0 100644
--- a/core/modules/views/tests/src/Plugin/views/display/BlockTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/views/display/BlockTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Plugin\views\display\BlockTest.
+ * Contains \Drupal\Tests\views\Unit\Plugin\views\display\BlockTest.
  */
 
-namespace Drupal\views\Tests\Plugin\views\display;
+namespace Drupal\Tests\views\Unit\Plugin\views\display;
 
 use Drupal\Tests\UnitTestCase;
 
diff --git a/core/modules/views/tests/src/PluginBaseTest.php b/core/modules/views/tests/src/Unit/PluginBaseTest.php
similarity index 98%
rename from core/modules/views/tests/src/PluginBaseTest.php
rename to core/modules/views/tests/src/Unit/PluginBaseTest.php
index e48dd00..4b57bd5 100644
--- a/core/modules/views/tests/src/PluginBaseTest.php
+++ b/core/modules/views/tests/src/Unit/PluginBaseTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\PluginBaseTest.
+ * Contains \Drupal\Tests\views\Unit\PluginBaseTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Tests\TestHelperPlugin;
diff --git a/core/modules/views/tests/src/PluginTypeListTest.php b/core/modules/views/tests/src/Unit/PluginTypeListTest.php
similarity index 89%
rename from core/modules/views/tests/src/PluginTypeListTest.php
rename to core/modules/views/tests/src/Unit/PluginTypeListTest.php
index 5d842f6..650d48e 100644
--- a/core/modules/views/tests/src/PluginTypeListTest.php
+++ b/core/modules/views/tests/src/Unit/PluginTypeListTest.php
@@ -1,10 +1,10 @@
 <?php
 /**
  * @file
- * Definition of Drupal\views\Tests\PluginTypeListTest.
+ * Definition of Drupal\Tests\views\Unit\PluginTypeListTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\views\ViewExecutable;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/modules/views/tests/src/Routing/ViewPageControllerTest.php b/core/modules/views/tests/src/Unit/Routing/ViewPageControllerTest.php
similarity index 98%
rename from core/modules/views/tests/src/Routing/ViewPageControllerTest.php
rename to core/modules/views/tests/src/Unit/Routing/ViewPageControllerTest.php
index 711c957..33630cd 100644
--- a/core/modules/views/tests/src/Routing/ViewPageControllerTest.php
+++ b/core/modules/views/tests/src/Unit/Routing/ViewPageControllerTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\Routing\ViewPageControllerTest.
+ * Contains \Drupal\Tests\views\Unit\Routing\ViewPageControllerTest.
  */
 
-namespace Drupal\views\Tests\Routing;
+namespace Drupal\Tests\views\Unit\Routing;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Routing\ViewPageController;
diff --git a/core/modules/views/tests/src/ViewExecutableFactoryTest.php b/core/modules/views/tests/src/Unit/ViewExecutableFactoryTest.php
similarity index 95%
rename from core/modules/views/tests/src/ViewExecutableFactoryTest.php
rename to core/modules/views/tests/src/Unit/ViewExecutableFactoryTest.php
index 2111de6..d9130d5 100644
--- a/core/modules/views/tests/src/ViewExecutableFactoryTest.php
+++ b/core/modules/views/tests/src/Unit/ViewExecutableFactoryTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\VIewExecutableFactoryTest.
+ * Contains \Drupal\Tests\views\Unit\VIewExecutableFactoryTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\ViewExecutableFactory;
diff --git a/core/modules/views/tests/src/ViewExecutableUnitTest.php b/core/modules/views/tests/src/Unit/ViewExecutableUnitTest.php
similarity index 95%
rename from core/modules/views/tests/src/ViewExecutableUnitTest.php
rename to core/modules/views/tests/src/Unit/ViewExecutableUnitTest.php
index c6ea1bb..13042df 100644
--- a/core/modules/views/tests/src/ViewExecutableUnitTest.php
+++ b/core/modules/views/tests/src/Unit/ViewExecutableUnitTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\ViewExecutableUnitTest.
+ * Contains \Drupal\Tests\views\Unit\ViewExecutableUnitTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Entity\View;
diff --git a/core/modules/views/tests/src/ViewsDataHelperTest.php b/core/modules/views/tests/src/Unit/ViewsDataHelperTest.php
similarity index 96%
rename from core/modules/views/tests/src/ViewsDataHelperTest.php
rename to core/modules/views/tests/src/Unit/ViewsDataHelperTest.php
index 260fee7..9016dbf 100644
--- a/core/modules/views/tests/src/ViewsDataHelperTest.php
+++ b/core/modules/views/tests/src/Unit/ViewsDataHelperTest.php
@@ -2,14 +2,15 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\ViewsDataHelperTest.
+ * Contains \Drupal\Tests\views\Unit\ViewsDataHelperTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Component\Utility\String;
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\ViewsDataHelper;
+use Drupal\views\Tests\ViewTestData;
 
 /**
  * @coversDefaultClass \Drupal\views\ViewsDataHelper
diff --git a/core/modules/views/tests/src/ViewsDataTest.php b/core/modules/views/tests/src/Unit/ViewsDataTest.php
similarity index 99%
rename from core/modules/views/tests/src/ViewsDataTest.php
rename to core/modules/views/tests/src/Unit/ViewsDataTest.php
index d06cd06..e2dbcf6 100644
--- a/core/modules/views/tests/src/ViewsDataTest.php
+++ b/core/modules/views/tests/src/Unit/ViewsDataTest.php
@@ -2,14 +2,15 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\ViewsDataTest.
+ * Contains \Drupal\Tests\views\Unit\ViewsDataTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Core\Language\Language;
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\ViewsData;
+use Drupal\views\Tests\ViewTestData;
 
 /**
  * @coversDefaultClass \Drupal\views\ViewsData
diff --git a/core/modules/views/tests/src/ViewsTest.php b/core/modules/views/tests/src/Unit/ViewsTest.php
similarity index 95%
rename from core/modules/views/tests/src/ViewsTest.php
rename to core/modules/views/tests/src/Unit/ViewsTest.php
index cb2be61..20db207 100644
--- a/core/modules/views/tests/src/ViewsTest.php
+++ b/core/modules/views/tests/src/Unit/ViewsTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views\Tests\ViewsTest.
+ * Contains \Drupal\Tests\views\Unit\ViewsTest.
  */
 
-namespace Drupal\views\Tests;
+namespace Drupal\Tests\views\Unit;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\Views;
diff --git a/core/modules/views_ui/tests/src/Form/Ajax/RearrangeFilterTest.php b/core/modules/views_ui/tests/src/Unit/Form/Ajax/RearrangeFilterTest.php
similarity index 82%
rename from core/modules/views_ui/tests/src/Form/Ajax/RearrangeFilterTest.php
rename to core/modules/views_ui/tests/src/Unit/Form/Ajax/RearrangeFilterTest.php
index 0166fef..a4bc4e4 100644
--- a/core/modules/views_ui/tests/src/Form/Ajax/RearrangeFilterTest.php
+++ b/core/modules/views_ui/tests/src/Unit/Form/Ajax/RearrangeFilterTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views_ui\Tests\Form\Ajax\RearrangeFilterTest.
+ * Contains \Drupal\Tests\views_ui\Unit\Form\Ajax\RearrangeFilterTest.
  */
 
-namespace Drupal\views_ui\Tests\Form\Ajax;
+namespace Drupal\Tests\views_ui\Unit\Form\Ajax;
 
 use Drupal\Tests\UnitTestCase;
 use Drupal\views_ui\Form\Ajax\RearrangeFilter;
diff --git a/core/modules/views_ui/tests/src/ViewListBuilderTest.php b/core/modules/views_ui/tests/src/Unit/ViewListBuilderTest.php
similarity index 98%
rename from core/modules/views_ui/tests/src/ViewListBuilderTest.php
rename to core/modules/views_ui/tests/src/Unit/ViewListBuilderTest.php
index 14b5f33..bcc03ff 100644
--- a/core/modules/views_ui/tests/src/ViewListBuilderTest.php
+++ b/core/modules/views_ui/tests/src/Unit/ViewListBuilderTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views_ui\Tests\ViewListBuilderTest.
+ * Contains \Drupal\Tests\views_ui\Unit\ViewListBuilderTest.
  */
 
-namespace Drupal\views_ui\Tests;
+namespace Drupal\Tests\views_ui\Unit;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Entity\EntityInterface;
diff --git a/core/modules/views_ui/tests/src/ViewUIObjectTest.php b/core/modules/views_ui/tests/src/Unit/ViewUIObjectTest.php
similarity index 97%
rename from core/modules/views_ui/tests/src/ViewUIObjectTest.php
rename to core/modules/views_ui/tests/src/Unit/ViewUIObjectTest.php
index 1828f76..c31306a 100644
--- a/core/modules/views_ui/tests/src/ViewUIObjectTest.php
+++ b/core/modules/views_ui/tests/src/Unit/ViewUIObjectTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\views_ui\Tests\ViewUIObjectTest.
+ * Contains \Drupal\Tests\views_ui\Unit\ViewUIObjectTest.
  */
 
-namespace Drupal\views_ui\Tests;
+namespace Drupal\Tests\views_ui\Unit;
 
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Tests\UnitTestCase;
diff --git a/core/tests/bootstrap.php b/core/tests/bootstrap.php
index 99fe34d..e74dc24 100644
--- a/core/tests/bootstrap.php
+++ b/core/tests/bootstrap.php
@@ -62,7 +62,7 @@ function drupal_phpunit_register_extension_dirs(Composer\Autoload\ClassLoader $l
     }
     if (is_dir($dir . '/tests/src')) {
       // Register the PSR-4 directory for PHPUnit test classes.
-      $loader->addPsr4('Drupal\\' . $extension . '\Tests\\', $dir . '/tests/src');
+      $loader->addPsr4('Drupal\\Tests\\' . $extension . '\\', $dir . '/tests/src');
     }
   }
 }