diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/PasswordItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/PasswordItem.php
index 7de771a..687860c 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/PasswordItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/PasswordItem.php
@@ -63,4 +63,13 @@ public function preSave() {
       }
     }
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isEmpty() {
+    $value = $this->get('value')->getValue();
+    return $value === NULL;
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItemBase.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItemBase.php
index 11ccec6..065310c 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItemBase.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItemBase.php
@@ -44,7 +44,8 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
    * {@inheritdoc}
    */
   public function isEmpty() {
-    return $this->value === NULL || $this->value === '';
+    $value = $this->get('value')->getValue();
+    return $value === NULL || $value === '';
   }
 
 }
diff --git a/core/modules/aggregator/src/Tests/FeedProcessorPluginTest.php b/core/modules/aggregator/src/Tests/FeedProcessorPluginTest.php
index 5142da5..2584021 100644
--- a/core/modules/aggregator/src/Tests/FeedProcessorPluginTest.php
+++ b/core/modules/aggregator/src/Tests/FeedProcessorPluginTest.php
@@ -47,9 +47,10 @@ public function testProcess() {
    */
   public function testDelete() {
     $feed = $this->createFeed();
+    $description = $feed->description->value ?: '';
     $this->updateAndDelete($feed, NULL);
     // Make sure the feed title is changed.
-    $entities = entity_load_multiple_by_properties('aggregator_feed', array('description' => $feed->description->value));
+    $entities = entity_load_multiple_by_properties('aggregator_feed', array('description' => $description));
     $this->assertTrue(empty($entities));
   }
 
diff --git a/core/modules/comment/src/Tests/Migrate/d6/MigrateCommentTest.php b/core/modules/comment/src/Tests/Migrate/d6/MigrateCommentTest.php
index 19e74fe..80404bb 100644
--- a/core/modules/comment/src/Tests/Migrate/d6/MigrateCommentTest.php
+++ b/core/modules/comment/src/Tests/Migrate/d6/MigrateCommentTest.php
@@ -44,6 +44,7 @@ protected function setUp() {
     $node = entity_create('node', array(
       'type' => 'story',
       'nid' => 1,
+      'title' => $this->randomString(),
     ));
     $node->enforceIsNew();
     $node->save();
diff --git a/core/modules/comment/src/Tests/Views/CommentUserNameTest.php b/core/modules/comment/src/Tests/Views/CommentUserNameTest.php
index f0ef7e6..cd7825a 100644
--- a/core/modules/comment/src/Tests/Views/CommentUserNameTest.php
+++ b/core/modules/comment/src/Tests/Views/CommentUserNameTest.php
@@ -50,6 +50,7 @@ protected function setUp($import_test_views = TRUE) {
     $storage
       ->create(array(
         'uid' => 0,
+        'name' => '',
         'status' => 0,
       ))
       ->save();
diff --git a/core/modules/file/src/Tests/Migrate/d6/MigrateUploadBase.php b/core/modules/file/src/Tests/Migrate/d6/MigrateUploadBase.php
index 17ea473..8305cf5 100644
--- a/core/modules/file/src/Tests/Migrate/d6/MigrateUploadBase.php
+++ b/core/modules/file/src/Tests/Migrate/d6/MigrateUploadBase.php
@@ -84,6 +84,7 @@ protected function setUp() {
         'type' => 'story',
         'nid' => $i,
         'vid' => array_shift($vids),
+        'title' => $this->randomString(),
       ));
       $node->enforceIsNew();
       $node->save();
diff --git a/core/modules/node/src/Tests/NodeAccessLanguageAwareCombinationTest.php b/core/modules/node/src/Tests/NodeAccessLanguageAwareCombinationTest.php
index 62a7b0c..d78c546 100644
--- a/core/modules/node/src/Tests/NodeAccessLanguageAwareCombinationTest.php
+++ b/core/modules/node/src/Tests/NodeAccessLanguageAwareCombinationTest.php
@@ -111,6 +111,7 @@ protected function setUp() {
       'private' => FALSE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 0;
     $node->save();
 
@@ -121,6 +122,7 @@ protected function setUp() {
       'private' => TRUE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 0;
     $node->save();
 
@@ -131,6 +133,7 @@ protected function setUp() {
       'private' => FALSE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 0;
     $node->save();
 
@@ -141,6 +144,7 @@ protected function setUp() {
       'private' => FALSE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 1;
     $node->save();
 
@@ -151,6 +155,7 @@ protected function setUp() {
       'private' => FALSE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 1;
     $node->save();
 
@@ -161,6 +166,7 @@ protected function setUp() {
       'private' => TRUE,
     ));
     $translation = $node->getTranslation('ca');
+    $translation->title = $this->randomString();
     $translation->field_private->value = 1;
     $node->save();
 
diff --git a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
index fc5c892..4ff9f22 100644
--- a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
@@ -106,6 +106,7 @@ function testEntityFormLanguage() {
 
     // Create a body translation and check the form language.
     $langcode2 = $this->langcodes[1];
+    $node->getTranslation($langcode2)->title->value = $this->randomString();
     $node->getTranslation($langcode2)->body->value = $this->randomMachineName(16);
     $node->getTranslation($langcode2)->setOwnerId($web_user->id());
     $node->save();
diff --git a/core/modules/system/src/Tests/Module/UninstallTest.php b/core/modules/system/src/Tests/Module/UninstallTest.php
index 4f5e193..4b8df60 100644
--- a/core/modules/system/src/Tests/Module/UninstallTest.php
+++ b/core/modules/system/src/Tests/Module/UninstallTest.php
@@ -51,7 +51,7 @@ function testUninstallPage() {
     $node_type->setThirdPartySetting('module_test', 'key', 'value');
     $node_type->save();
     // Add a node to prevent node from being uninstalled.
-    $node = entity_create('node', array('type' => 'uninstall_blocker'));
+    $node = entity_create('node', array('type' => 'uninstall_blocker', 'title' => $this->randomString()));
     $node->save();
 
     $this->drupalGet('admin/modules/uninstall');
diff --git a/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php b/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php
index 567ae06..ef92e11 100644
--- a/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php
+++ b/core/modules/user/src/Tests/Condition/UserRoleConditionTest.php
@@ -88,6 +88,7 @@ protected function setUp() {
 
     // Setup an anonymous user for our tests.
     $this->anonymous = User::create(array(
+      'name' => '',
       'uid' => 0,
     ));
     $this->anonymous->save();
diff --git a/core/modules/user/src/UserNameItem.php b/core/modules/user/src/UserNameItem.php
index 0e18749..1f66bce 100644
--- a/core/modules/user/src/UserNameItem.php
+++ b/core/modules/user/src/UserNameItem.php
@@ -19,7 +19,7 @@ class UserNameItem extends StringItem {
    */
   public function isEmpty() {
     // Anonymous users do not store anything in the database.
-    if ($this->getEntity()->id() == 0) {
+    if ($this->getEntity()->id() === 0) {
       return $this->value === NULL;
     }