diff --git a/core/modules/config/lib/Drupal/config/Tests/Storage/CachedStorageTest.php b/core/modules/config/lib/Drupal/config/Tests/Storage/CachedStorageTest.php
new file mode 100644
index 0000000..196d8d0
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/Storage/CachedStorageTest.php
@@ -0,0 +1,120 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\Storage\CachedStorageTest.
+ */
+
+namespace Drupal\config\Tests\Storage;
+
+use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\CachedStorage;
+use Drupal\Core\Database\Database;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+
+/**
+ * Tests CachedStorage operations.
+ */
+class CachedStorageTest extends ConfigStorageTestBase {
+
+  /**
+   * The cache backend the cached storage is using.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface
+   */
+  protected $cache;
+
+  /**
+   * The file storage the cached storage is using.
+   *
+   * @var \Drupal\Core\Config\FileStorage
+   */
+  protected $filestorage;
+
+  public static function getInfo() {
+    return array(
+      'name' => 'CachedStorage operations',
+      'description' => 'Tests CachedStorage operations.',
+      'group' => 'Configuration',
+    );
+  }
+
+  function setUp() {
+    parent::setUp();
+    $this->filestorage = new FileStorage($this->configDirectories[CONFIG_ACTIVE_DIRECTORY]);
+    $this->cache = \Drupal::service('cache_factory')->get('config');
+    $this->storage = new CachedStorage($this->filestorage, $this->cache);
+    // ::listAll() verifications require other configuration data to exist.
+    $this->storage->write('system.performance', array());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testInvalidStorage() {
+    // No-op as this test does not make sense.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testInvalidData() {
+    // No-op as this test does not make sense.
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function read($name) {
+    $data = $this->cache->get($name);
+    // Cache misses fall through to the underlying storage.
+    return $data ? $data->data : $this->filestorage->read($name);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function insert($name, $data) {
+    // Try writing to the file storage first catch exceptions so that we can do
+    // the invalid data tests.
+    try {
+      $this->filestorage->write($name, $data);
+      $this->cache->set($name, $data);
+    }
+    catch (\Exception $e) {
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function update($name, $data) {
+    // Try writing to the file storage first catch exceptions so that we can do
+    // the invalid data tests.
+    try {
+      $this->filestorage->write($name, $data);
+      $this->cache->set($name, $data);
+    }
+    catch (\Exception $e) {
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function delete($name) {
+    $this->cache->delete($name);
+    unlink($this->filestorage->getFilePath($name));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function containerBuild(ContainerBuilder $container) {
+    parent::containerBuild($container);
+    // Use the regular database cache backend to aid testing.
+    $container->register('cache_factory', 'Drupal\Core\Cache\DatabaseBackendFactory')
+      ->addArgument(Database::getConnection());
+  }
+
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php b/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
index 925ecbd..8996359 100644
--- a/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
+++ b/core/modules/config/lib/Drupal/config/Tests/Storage/ConfigStorageTestBase.php
@@ -24,6 +24,11 @@
 abstract class ConfigStorageTestBase extends DrupalUnitTestBase {
 
   /**
+   * @var \Drupal\Core\Config\StorageInterface;
+   */
+  protected $storage;
+
+  /**
    * Tests storage CRUD operations.
    *
    * @todo Coverage: Trigger PDOExceptions / Database exceptions.
@@ -38,17 +43,6 @@ function testCRUD() {
     $data = $this->storage->read($name);
     $this->assertIdentical($data, FALSE);
 
-    // Reading a name containing non-decodeable data returns FALSE.
-    $this->insert($name, '');
-    $data = $this->storage->read($name);
-    $this->assertIdentical($data, FALSE);
-
-    $this->update($name, 'foo');
-    $data = $this->storage->read($name);
-    $this->assertIdentical($data, FALSE);
-
-    $this->delete($name);
-
     // Writing data returns TRUE and the data has been written.
     $data = array('foo' => 'bar');
     $result = $this->storage->write($name, $data);
@@ -90,14 +84,6 @@ function testCRUD() {
     $result = $this->storage->delete($name);
     $this->assertIdentical($result, FALSE);
 
-    // Reading from a non-existing storage bin returns FALSE.
-    $result = $this->invalidStorage->read($name);
-    $this->assertIdentical($result, FALSE);
-
-    // Listing on a non-existing storage bin returns an empty array.
-    $result = $this->invalidStorage->listAll();
-    $this->assertIdentical($result, array());
-
     // Deleting all names with prefix deletes the appropriate data and returns
     // TRUE.
     $files = array(
@@ -114,35 +100,57 @@ function testCRUD() {
     $this->assertIdentical($result, TRUE);
     $this->assertIdentical($names, array());
 
-
-    // Deleting from a non-existing storage bin throws an exception.
+    // Test renaming an object that does not exist throws an exception.
     try {
-      $this->invalidStorage->delete($name);
-      $this->fail('Exception not thrown upon deleting from a non-existing storage bin.');
+      $this->storage->rename('config_test.storage_does_not_exist', 'config_test.storage_does_not_exist_rename');
     }
     catch (\Exception $e) {
       $class = get_class($e);
-      $this->pass($class . ' thrown upon deleting from a non-existing storage bin.');
+      $this->pass($class . ' thrown upon renaming a nonexistent storage bin.');
     }
 
-    // Test renaming an object that does not exist throws an exception.
+    // Test renaming to an object that already exists throws an exception.
     try {
-      $this->storage->rename('config_test.storage_does_not_exist', 'config_test.storage_does_not_exist_rename');
+      $this->storage->rename('system.cron', 'system.performance');
     }
     catch (\Exception $e) {
       $class = get_class($e);
       $this->pass($class . ' thrown upon renaming a nonexistent storage bin.');
     }
+  }
 
-    // Test renaming to an object that already exists throws an exception.
+  /**
+   * Tests an invalid storage.
+   */
+  public function testInvalidStorage() {
+    $name = 'config_test.storage';
+
+    // Write something to the valid storage to prove that the storages do not
+    // pollute one another.
+    $data = array('foo' => 'bar');
+    $result = $this->storage->write($name, $data);
+    $this->assertIdentical($result, TRUE);
+
+    $raw_data = $this->read($name);
+    $this->assertIdentical($raw_data, $data);
+
+    // Reading from a non-existing storage bin returns FALSE.
+    $result = $this->invalidStorage->read($name);
+    $this->assertIdentical($result, FALSE);
+
+    // Deleting from a non-existing storage bin throws an exception.
     try {
-      $this->storage->rename('system.cron', 'system.performance');
+      $this->invalidStorage->delete($name);
+      $this->fail('Exception not thrown upon deleting from a non-existing storage bin.');
     }
     catch (\Exception $e) {
       $class = get_class($e);
-      $this->pass($class . ' thrown upon renaming a nonexistent storage bin.');
+      $this->pass($class . ' thrown upon deleting from a non-existing storage bin.');
     }
 
+    // Listing on a non-existing storage bin returns an empty array.
+    $result = $this->invalidStorage->listAll();
+    $this->assertIdentical($result, array());
     // Writing to a non-existing storage bin creates the bin.
     $this->invalidStorage->write($name, array('foo' => 'bar'));
     $result = $this->invalidStorage->read($name);
@@ -150,6 +158,22 @@ function testCRUD() {
   }
 
   /**
+   * Test that invalid data can not be read from the storage.
+   */
+  public function testInvalidData() {
+    $name = 'config_test.storage';
+
+    // Reading a name containing non-decodeable data returns FALSE.
+    $this->insert($name, '');
+    $data = $this->storage->read($name);
+    $this->assertIdentical($data, FALSE);
+
+    $this->update($name, 'foo');
+    $data = $this->storage->read($name);
+    $this->assertIdentical($data, FALSE);
+  }
+
+  /**
    * Tests storage writing and reading data preserving data type.
    */
   function testDataTypes() {