diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
index e9526d8..f35b254 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchMultilingualEntityTest.php
@@ -49,8 +49,8 @@ function setUp() {
     // Make the body field translatable.
     // The parent class has already created the article and page content types.
     $field = field_info_field('body');
-    $field['translatable'] = TRUE;
-    field_update_field($field);
+    $field->translatable = TRUE;
+    $field->save();
 
     // Create a few page nodes with multilingual body values.
     $default_format = filter_default_format();
diff --git a/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php b/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
index dfbb7ba..48d0293 100644
--- a/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/EntityResolverTest.php
@@ -34,22 +34,20 @@ protected function setUp() {
     parent::setUp();
 
     // Create the test field.
-    $field = array(
+    entity_create('field_entity', array(
       'settings' => array(
         'target_type' => 'entity_test_mulrev',
       ),
       'field_name' => 'field_test_entity_reference',
       'type' => 'entity_reference',
-    );
-    field_create_field($field);
+    ))->save();
 
     // Create the test field instance.
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test_mulrev',
       'field_name' => 'field_test_entity_reference',
       'bundle' => 'entity_test_mulrev',
-    );
-    field_create_instance($instance);
+    ))->save();
   }
 
   /**
diff --git a/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php b/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
index 1d9bff6..74fa8d9 100644
--- a/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/NormalizerTestBase.php
@@ -26,13 +26,13 @@ protected function setUp() {
     $this->installConfig(array('field'));
 
     // Auto-create a field for testing.
-    field_create_field(array(
+    entity_create('field_entity', array(
       'field_name' => 'field_test_text',
       'type' => 'text',
       'cardinality' => 1,
       'translatable' => FALSE,
-    ));
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test_mulrev',
       'field_name' => 'field_test_text',
       'bundle' => 'entity_test_mulrev',
@@ -41,7 +41,7 @@ protected function setUp() {
         'type' => 'text_textfield',
         'weight' => 0,
       ),
-    );
-    field_create_instance($instance);
+    ))->save();
   }
+
 }
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
index b2eed63..4615b39 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/DrupalUnitTestBaseTest.php
@@ -231,17 +231,16 @@ function testEnableModulesFixedList() {
       'bundle' => 'entity_test',
       'mode' => 'default',
     ));
-    $field = array(
+    $field = entity_create('field_entity', array(
       'field_name' => 'test_field',
       'type' => 'test_field'
-    );
-    field_create_field($field);
-    $instance = array(
-      'field_name' => $field['field_name'],
+    ));
+    $field->save();
+    entity_create('field_instance', array(
+      'field_name' => $field->id(),
       'entity_type' => 'entity_test',
       'bundle' => 'entity_test',
-    );
-    field_create_instance($instance);
+    ))->save();
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php b/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
index d3ba0b7..f15f382 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Ajax/MultiFormTest.php
@@ -34,18 +34,16 @@ function setUp() {
 
     // Create a multi-valued field for 'page' nodes to use for Ajax testing.
     $field_name = 'field_ajax_test';
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => $field_name,
       'type' => 'text',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
-    );
-    field_create_field($field);
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'field_name' => $field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
-    );
-    field_create_instance($instance);
+    ))->save();
     entity_get_form_display('node', 'page', 'default')
       ->setComponent($field_name, array('type' => 'text_default'))
       ->save();
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
index 93fc552..4d24a51 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityFieldTest.php
@@ -598,8 +598,8 @@ public function testComputedProperties() {
   protected function assertComputedProperties($entity_type) {
     // Make the test text field processed.
     $instance = field_info_instance($entity_type, 'field_test_text', $entity_type);
-    $instance['settings']['text_processing'] = 1;
-    field_update_instance($instance);
+    $instance->settings['text_processing'] = 1;
+    $instance->save();
 
     $entity = $this->createTestEntity($entity_type);
     $entity->field_test_text->value = "The <strong>text</strong> text to filter.";
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
index 54c6934..faa7090 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryAggregateTest.php
@@ -60,18 +60,17 @@ public function setUp() {
 
     // Add some fieldapi fields to be used in the test.
     for ($i = 1; $i <= 2; $i++) {
-      $field = array(
-        'field_name' => 'field_test_' . $i,
+      $field_name = 'field_test_' . $i;
+      entity_create('field_entity', array(
+        'field_name' => $field_name,
         'type' => 'number_integer',
         'cardinality' => 2,
-      );
-      field_create_field($field);
-      $instance = array(
-        'field_name' => $field['field_name'],
+      ))->save();
+      entity_create('field_instance', array(
+        'field_name' => $field_name,
         'entity_type' => 'entity_test',
         'bundle' => 'entity_test',
-      );
-      field_create_instance($instance);
+      ))->save();
     }
 
     $entity = $this->entityStorageController->create(array(
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
index f36fca7..7a40d9b 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryRelationshipTest.php
@@ -85,14 +85,13 @@ public function setUp() {
       'type' => 'taxonomy_term_reference',
     );
     $field['settings']['allowed_values']['vocabulary'] = $vocabulary->id();
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     // Third, create the instance.
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => 'entity_test',
       'field_name' => $this->fieldName,
       'bundle' => 'entity_test',
-    );
-    field_create_instance($instance);
+    ))->save();
     // Create two terms and also two accounts.
     for ($i = 0; $i <= 1; $i++) {
       $term = entity_create('taxonomy_term', array(
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
index 8b5b19b..b0e52b2 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
@@ -61,13 +61,13 @@ function setUp() {
     $figures = drupal_strtolower($this->randomName());
     $greetings = drupal_strtolower($this->randomName());
     foreach (array($figures => 'shape', $greetings => 'text') as $field_name => $field_type) {
-      $field = array(
+      $fields[] = $field = entity_create('field_instance', array(
         'field_name' => $field_name,
         'type' => $field_type,
         'cardinality' => 2,
         'translatable' => TRUE,
-      );
-      $fields[] = field_create_field($field);
+      ));
+      $field->save();
     }
     $bundles = array();
     for ($i = 0; $i < 2; $i++) {
@@ -78,12 +78,12 @@ function setUp() {
       } while ($bundles && strtolower($bundles[0]) >= strtolower($bundle));
       entity_test_create_bundle($bundle);
       foreach ($fields as $field) {
-        $instance = array(
+        $instance = entity_create('field_instance', array(
           'field_name' => $field['field_name'],
           'entity_type' => 'entity_test_mulrev',
           'bundle' => $bundle,
-        );
-        field_create_instance($instance);
+        ));
+        $instance->save();
       }
       $bundles[] = $bundle;
     }
@@ -410,12 +410,12 @@ protected function testCount() {
     // can test whether cross entity type fields produce the correct query.
     $field_name = $this->figures;
     $bundle = $this->randomName();
-    $instance = array(
+    $instance = entity_create('field_instance', array(
       'field_name' => $field_name,
       'entity_type' => 'entity_test',
       'bundle' => $bundle,
-    );
-    field_create_instance($instance);
+    ));
+    $instance->save();
 
     $entity = entity_create('entity_test', array(
       'id' => 1,
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
index 2a6e833..6623d3f 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationFormTest.php
@@ -105,8 +105,8 @@ function testEntityFormLanguage() {
 
     // Make body translatable.
     $field = field_info_field('body');
-    $field['translatable'] = TRUE;
-    field_update_field($field);
+    $field->translatable = TRUE;
+    $field->save();
     $field = field_info_field('body');
     $this->assertTrue($field['translatable'], 'Field body is translatable.');
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
index 919565c..a235add 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityTranslationTest.php
@@ -50,23 +50,21 @@ function setUp() {
 
     // Create a translatable test field.
     $this->field_name = drupal_strtolower($this->randomName() . '_field_name');
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => $this->field_name,
       'type' => 'text',
       'cardinality' => 4,
       'translatable' => TRUE,
-    );
-    field_create_field($field);
+    ))->save();
     $this->field = field_read_field($this->field_name);
 
     // Create instance in all entity variations.
     foreach (entity_test_entity_types() as $entity_type) {
-      $instance = array(
+      entity_create('field_instance', array(
         'field_name' => $this->field_name,
         'entity_type' => $entity_type,
         'bundle' => $entity_type,
-      );
-      field_create_instance($instance);
+      ))->save();
       $this->instance[$entity_type] = field_read_instance($entity_type, $this->field_name, $entity_type);
     }
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
index f049ac8..ff1bad3 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/ArbitraryRebuildTest.php
@@ -33,15 +33,13 @@ function setUp() {
     parent::setUp();
 
     // Auto-create a field for testing.
-    $field = array(
+    entity_create('field_entity', array(
       'field_name' => 'test_multiple',
       'type' => 'text',
       'cardinality' => -1,
       'translatable' => FALSE,
-    );
-    field_create_field($field);
-
-    $instance = array(
+    ))->save();
+    entity_create('field_instance', array(
       'entity_type' => 'user',
       'field_name' => 'test_multiple',
       'bundle' => 'user',
@@ -49,8 +47,7 @@ function setUp() {
       'settings' => array(
         'user_register_form' => TRUE,
       ),
-    );
-    field_create_instance($instance);
+    ))->save();
     entity_get_form_display('user', 'user', 'default')
       ->setComponent('test_multiple', array(
         'type' => 'text_textfield',
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
index 8e9f649..c580e88 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/RebuildTest.php
@@ -76,13 +76,13 @@ function testPreserveFormActionAfterAJAX() {
       'type' => 'text',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
     );
-    field_create_field($field);
+    entity_create('field_entity', $field)->save();
     $instance = array(
       'field_name' => $field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
     );
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display('node', 'page', 'default')
       ->setComponent($field_name, array('type' => 'text_test'))
       ->save();
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.install b/core/modules/system/tests/modules/entity_test/entity_test.install
index f7b8726..d6f1b34 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.install
+++ b/core/modules/system/tests/modules/entity_test/entity_test.install
@@ -10,13 +10,12 @@
  */
 function entity_test_install() {
   // Auto-create a field for testing.
-  $field = array(
+  entity_create('field_entity', array(
     'field_name' => 'field_test_text',
     'type' => 'text',
     'cardinality' => 1,
     'translatable' => FALSE,
-  );
-  field_create_field($field);
+  ))->save();
 
   $entity_types = array(
     'entity_test',
@@ -25,13 +24,12 @@ function entity_test_install() {
     'entity_test_mulrev',
   );
   foreach ($entity_types as $entity_type) {
-    $instance = array(
+    entity_create('field_instance', array(
       'entity_type' => $entity_type,
       'field_name' => 'field_test_text',
       'bundle' => $entity_type,
       'label' => 'Test text-field',
-    );
-    field_create_instance($instance);
+    ))->save();
 
     entity_get_form_display($entity_type, $entity_type, 'default')
       ->setComponent('field_test_text', array('type' => 'text_text'))
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
index 8da2c2b..170b8ed 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
@@ -195,34 +195,34 @@ function testRegistrationDefaultValues() {
    */
   function testRegistrationWithUserFields() {
     // Create a field, and an instance on 'user' entity type.
-    $field = array(
+    $field = entity_create('field_entity', array(
       'type' => 'test_field',
       'field_name' => 'test_user_field',
       'cardinality' => 1,
-    );
-    field_create_field($field);
-    $instance = array(
+    ));
+    $field->save();
+    $instance = entity_create('field_instance', array(
       'field_name' => 'test_user_field',
       'entity_type' => 'user',
       'label' => 'Some user field',
       'bundle' => 'user',
       'required' => TRUE,
       'settings' => array('user_register_form' => FALSE),
-    );
-    field_create_instance($instance);
+    ));
+    $instance->save();
     entity_get_form_display('user', 'user', 'default')
       ->setComponent('test_user_field', array('type' => 'test_field_widget'))
       ->save();
 
     // Check that the field does not appear on the registration form.
     $this->drupalGet('user/register');
-    $this->assertNoText($instance['label'], 'The field does not appear on user registration form');
+    $this->assertNoText($instance->id(), 'The field does not appear on user registration form');
 
     // Have the field appear on the registration form.
-    $instance['settings']['user_register_form'] = TRUE;
-    field_update_instance($instance);
+    $instance->settings['user_register_form'] = TRUE;
+    $instance->save();
     $this->drupalGet('user/register');
-    $this->assertText($instance['label'], 'The field appears on user registration form');
+    $this->assertText($instance->id(), 'The field appears on user registration form');
 
     // Check that validation errors are correctly reported.
     $edit = array();
@@ -231,11 +231,11 @@ function testRegistrationWithUserFields() {
     // Missing input in required field.
     $edit['test_user_field[und][0][value]'] = '';
     $this->drupalPost(NULL, $edit, t('Create new account'));
-    $this->assertRaw(t('@name field is required.', array('@name' => $instance['label'])), 'Field validation error was correctly reported.');
+    $this->assertRaw(t('@name field is required.', array('@name' => $instance->id())), 'Field validation error was correctly reported.');
     // Invalid input.
     $edit['test_user_field[und][0][value]'] = '-1';
     $this->drupalPost(NULL, $edit, t('Create new account'));
-    $this->assertRaw(t('%name does not accept the value -1.', array('%name' => $instance['label'])), 'Field validation error was correctly reported.');
+    $this->assertRaw(t('%name does not accept the value -1.', array('%name' => $instance->id())), 'Field validation error was correctly reported.');
 
     // Submit with valid data.
     $value = rand(1, 255);
@@ -247,8 +247,8 @@ function testRegistrationWithUserFields() {
     $this->assertEqual($new_user->test_user_field->value, $value, 'The field value was correclty saved.');
 
     // Check that the 'add more' button works.
-    $field['cardinality'] = FIELD_CARDINALITY_UNLIMITED;
-    field_update_field($field);
+    $field->cardinality = FIELD_CARDINALITY_UNLIMITED;
+    $field->save();
     foreach (array('js', 'nojs') as $js) {
       $this->drupalGet('user/register');
       // Add two inputs.
diff --git a/core/modules/user/user.install b/core/modules/user/user.install
index 69d96b6..d445d41 100644
--- a/core/modules/user/user.install
+++ b/core/modules/user/user.install
@@ -317,7 +317,7 @@ function user_install_picture_field() {
       'default_image' => FALSE,
     ),
   );
-  $field = field_create_field($field);
+  entity_create('field_entity', $field)->save();
 
   $instance = array(
     'field_name' => 'user_picture',
@@ -337,7 +337,7 @@ function user_install_picture_field() {
       'default_image' => 0,
     ),
   );
-  field_create_instance($instance);
+  entity_create('field_instance', $instance)->save();
 
   // Assign form display settings for the 'default' view mode.
   entity_get_form_display('user', 'user', 'default')
diff --git a/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php b/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
index 9cfdce9..8bcf05b 100644
--- a/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/DefaultViewsTest.php
@@ -61,7 +61,7 @@ protected function setUp() {
 
     // Setup a field and instance.
     $this->field_name = drupal_strtolower($this->randomName());
-    $this->field = array(
+    entity_create('field_entity', array(
       'field_name' => $this->field_name,
       'type' => 'taxonomy_term_reference',
       'settings' => array(
@@ -72,14 +72,13 @@ protected function setUp() {
           ),
         ),
       )
-    );
-    field_create_field($this->field);
+    ))->save();
     $this->instance = array(
       'field_name' => $this->field_name,
       'entity_type' => 'node',
       'bundle' => 'page',
-    );
-    field_create_instance($this->instance);
+    ));
+    $this->instance->save();
 
     // Create a time in the past for the archive.
     $time = REQUEST_TIME - 3600;
diff --git a/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php b/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
index bb52895..2f870d8 100644
--- a/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/Wizard/TaggedWithTest.php
@@ -55,7 +55,7 @@ function setUp() {
     $this->tag_vocabulary->save();
 
     // Create the tag field itself.
-    $this->tag_field = array(
+    $this->tag_field = entity_create('field_entity', array(
       'field_name' => 'field_views_testing_tags',
       'type' => 'taxonomy_term_reference',
       'cardinality' => FIELD_CARDINALITY_UNLIMITED,
@@ -67,8 +67,8 @@ function setUp() {
           ),
         ),
       ),
-    );
-    field_create_field($this->tag_field);
+    ));
+    $this->tag_field->save();
 
     // Create an instance of the tag field on one of the content types, and
     // configure it to display an autocomplete widget.
@@ -77,7 +77,7 @@ function setUp() {
       'entity_type' => 'node',
       'bundle' => $this->node_type_with_tags->type,
     );
-    field_create_instance($this->tag_instance);
+    entity_create('field_instance', $this->tag_instance)->save();
 
     entity_get_form_display('node', $this->node_type_with_tags->type, 'default')
       ->setComponent('field_views_testing_tags', array(
@@ -108,7 +108,7 @@ function testTaggedWith() {
     $node_add_path = 'node/add/' . $this->node_type_with_tags->type;
 
     // Create three nodes, with different tags.
-    $tag_field = $this->tag_field['field_name'] . '[' . Language::LANGCODE_NOT_SPECIFIED . ']';
+    $tag_field = $this->tag_field->id() . '[' . Language::LANGCODE_NOT_SPECIFIED . ']';
     $edit = array();
     $edit['title'] = $node_tag1_title = $this->randomName();
     $edit[$tag_field] = 'tag1';
@@ -189,7 +189,7 @@ function testTaggedWithByNodeType() {
     // "tagged with" form element should not appear for it too.
     $instance = $this->tag_instance;
     $instance['bundle'] = $this->node_type_without_tags->type;
-    field_create_instance($instance);
+    entity_create('field_instance', $instance)->save();
     entity_get_form_display('node', $this->node_type_without_tags->type, 'default')
       ->setComponent('field_views_testing_tags', array(
         'type' => 'taxonomy_autocomplete',