diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
@@ -165,13 +165,15 @@
     $meta = config_typed()->get('system.site');
     $property = $meta->get('name');
     $this->assertTrue($property instanceof StringInterface, 'Got the right wrapper fo the site name property.');
-    $this->assertEqual($property->getPluginId(), 'label', 'Got the right string type for site name data.');
     $this->assertEqual($property->getValue(), 'Drupal', 'Got the right string value for site name data.');
+    $definition = $property->getDefinition();
+    $this->assertTrue($definition['translatable'], 'Got the right translatability setting for site name data.');
 
     $property = $meta->get('page')->get('front');
     $this->assertTrue($property instanceof StringInterface, 'Got the right wrapper fo the page.front property.');
-    $this->assertEqual($property->getPluginId(), 'path', 'Got the right type for page.front data (undefined).');
     $this->assertEqual($property->getValue(), 'user', 'Got the right value for page.front data.');
+    $definition = $property->getDefinition();
+    $this->assertTrue(empty($definition['translatable']), 'Got the right translatability setting for page.front data.');
 
     // Check nested array of properties.
     $list = $meta->get('page');
diff -u b/core/modules/system/lib/Drupal/system/Tests/TypedData/TypedDataTest.php b/core/modules/system/lib/Drupal/system/Tests/TypedData/TypedDataTest.php
--- b/core/modules/system/lib/Drupal/system/Tests/TypedData/TypedDataTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/TypedData/TypedDataTest.php
@@ -47,17 +47,13 @@
   }
 
   /**
-   * Creates a typed data object and executes some basic assertions.
+   * Creates a typed data object and ensures it implements TypedDataInterface.
    *
    * @see Drupal\Core\TypedData\TypedDataManager::create().
    */
   protected function createTypedData($definition, $value = NULL, $name = NULL) {
-    // Construct the object.
     $data = $this->typedData->create($definition, $value, $name);
-    // Assert the definition of the wrapper.
     $this->assertTrue($data instanceof \Drupal\Core\TypedData\TypedDataInterface, 'Typed data object is an instance of the typed data interface.');
-    $definition = $data->getDefinition();
-    $this->assertTrue(!empty($definition['type']), format_string('!type data definition was returned.', array('!type' => $definition['type'])));
     return $data;
   }
 
@@ -67,6 +63,7 @@
   public function testGetAndSet() {
     // Boolean type.
     $typed_data = $this->createTypedData(array('type' => 'boolean'), TRUE);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\BooleanInterface, 'Typed data object is an instance of BooleanInterface.');
     $this->assertTrue($typed_data->getValue() === TRUE, 'Boolean value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $typed_data->setValue(FALSE);
@@ -82,6 +79,7 @@
     // String type.
     $value = $this->randomString();
     $typed_data = $this->createTypedData(array('type' => 'string'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\StringInterface, 'Typed data object is an instance of StringInterface.');
     $this->assertTrue($typed_data->getValue() === $value, 'String value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $new_value = $this->randomString();
@@ -99,6 +97,7 @@
     // Integer type.
     $value = rand();
     $typed_data = $this->createTypedData(array('type' => 'integer'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\IntegerInterface, 'Typed data object is an instance of IntegerInterface.');
     $this->assertTrue($typed_data->getValue() === $value, 'Integer value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $new_value = rand();
@@ -115,6 +114,7 @@
     // Float type.
     $value = 123.45;
     $typed_data = $this->createTypedData(array('type' => 'float'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\FloatInterface, 'Typed data object is an instance of FloatInterface.');
     $this->assertTrue($typed_data->getValue() === $value, 'Float value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $new_value = 678.90;
@@ -131,6 +131,7 @@
     // Date Time type.
     $value = '2014-01-01T20:00:00+00:00';
     $typed_data = $this->createTypedData(array('type' => 'datetime_iso8601'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\DateTimeInterface, 'Typed data object is an instance of DateTimeInterface.');
     $this->assertTrue($typed_data->getValue() == $value, 'Date value was fetched.');
     $this->assertEqual($typed_data->getValue(), $typed_data->getDateTime()->format('c'), 'Value representation of a date is ISO 8601');
     $this->assertEqual($typed_data->validate()->count(), 0);
@@ -156,6 +157,7 @@
     // Timestamp type.
     $value = REQUEST_TIME;
     $typed_data = $this->createTypedData(array('type' => 'timestamp'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\DateTimeInterface, 'Typed data object is an instance of DateTimeInterface.');
     $this->assertTrue($typed_data->getValue() == $value, 'Timestamp value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $new_value = REQUEST_TIME + 1;
@@ -178,6 +180,7 @@
     // DurationIso8601 type.
     $value = 'PT20S';
     $typed_data = $this->createTypedData(array('type' => 'duration_iso8601'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\DurationInterface, 'Typed data object is an instance of DurationInterface.');
     $this->assertIdentical($typed_data->getValue(), $value, 'DurationIso8601 value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $typed_data->setValue('P40D');
@@ -201,6 +204,7 @@
     // Time span type.
     $value = 20;
     $typed_data = $this->createTypedData(array('type' => 'timespan'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\DurationInterface, 'Typed data object is an instance of DurationInterface.');
     $this->assertIdentical($typed_data->getValue(), $value, 'Time span value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $typed_data->setValue(60 * 60 * 4);
@@ -223,6 +227,7 @@
     // URI type.
     $uri = 'http://example.com/foo/';
     $typed_data = $this->createTypedData(array('type' => 'uri'), $uri);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\UriInterface, 'Typed data object is an instance of UriInterface.');
     $this->assertTrue($typed_data->getValue() === $uri, 'URI value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     $typed_data->setValue($uri . 'bar.txt');
@@ -249,6 +254,7 @@
     // Email type.
     $value = $this->randomString();
     $typed_data = $this->createTypedData(array('type' => 'email'), $value);
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\StringInterface, 'Typed data object is an instance of StringInterface.');
     $this->assertIdentical($typed_data->getValue(), $value, 'E-mail value was fetched.');
     $new_value = 'test@example.com';
     $typed_data->setValue($new_value);
@@ -263,6 +269,7 @@
 
     // Binary type.
     $typed_data = $this->createTypedData(array('type' => 'binary'), $files[0]->getFileUri());
+    $this->assertTrue($typed_data instanceof \Drupal\Core\TypedData\Type\BinaryInterface, 'Typed data object is an instance of BinaryInterface.');
     $this->assertTrue(is_resource($typed_data->getValue()), 'Binary value was fetched.');
     $this->assertEqual($typed_data->validate()->count(), 0);
     // Try setting by URI.
diff -u b/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextItemBase.php b/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextItemBase.php
--- b/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextItemBase.php
+++ b/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextItemBase.php
@@ -70,7 +70,7 @@
   /**
    * {@inheritdoc}
    */
-  public function prepareCache() {
+  public function prepareCache($properties = array('value')) {
     // Where possible, generate the sanitized version of each field early so
     // that it is cached in the field cache. This avoids the need to look up the
     // field in the filter cache separately.
@@ -78,9 +78,8 @@
     if (!$text_processing || filter_format_allowcache($this->get('format')->getValue())) {
       $itemBC = $this->getValue();
       $langcode = $this->getParent()->getParent()->language()->id;
-      $this->set('safe_value', text_sanitize($text_processing, $langcode, $itemBC, 'value'));
-      if ($this->getPluginId() == 'field_item:text_with_summary') {
-        $this->set('safe_summary', text_sanitize($text_processing, $langcode, $itemBC, 'summary'));
+      foreach ($properties as $name) {
+        $this->set("safe_$name", text_sanitize($text_processing, $langcode, $itemBC, $name));
       }
     }
   }
only in patch2:
unchanged:
--- a/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextWithSummaryItem.php
+++ b/core/modules/text/lib/Drupal/text/Plugin/field/field_type/TextWithSummaryItem.php
@@ -128,4 +128,11 @@ public function instanceSettingsForm(array $form, array &$form_state) {
     return $element;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function prepareCache($properties = array('value', 'summary')) {
+    parent::prepareCache($properties);
+  }
+
 }