diff --git a/core/config/schema/core.entity.data_types.schema.yml b/core/config/schema/core.entity.data_types.schema.yml
index f0b87ee..36e59fb 100644
--- a/core/config/schema/core.entity.data_types.schema.yml
+++ b/core/config/schema/core.entity.data_types.schema.yml
@@ -18,6 +18,9 @@ entity_field_view_display_base:
     label:
       type: string
       label: 'Label setting machine name'
+    settings:
+      type: sequence
+      label: 'Settings'
 
 # Schema for the base of the form mode display format settings.
 entity_field_form_display_base:
@@ -34,3 +37,6 @@ entity_field_form_display_base:
       label: 'Third party settings'
       sequence:
         - type: entity_form_display.third_party.[%key]
+    settings:
+      type: sequence
+      label: 'Settings'
diff --git a/core/config/schema/core.entity.schema.yml b/core/config/schema/core.entity.schema.yml
index 63a35eb..20a820f 100644
--- a/core/config/schema/core.entity.schema.yml
+++ b/core/config/schema/core.entity.schema.yml
@@ -148,32 +148,14 @@ entity_form_display.field.string_textfield:
 entity_form_display.field.datetime_timestamp:
   type: entity_field_form_display_base
   label: 'Datetime timestamp display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.boolean_checkbox:
   type: entity_field_form_display_base
   label: 'Boolean checkbox display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.hidden:
   type: entity_field_form_display_base
   label: '- Hidden - format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.number:
   type: entity_field_form_display_base
@@ -238,29 +220,11 @@ entity_view_display.field.number_integer:
 entity_view_display.field.number_unformatted:
   type: entity_field_view_display_base
   label: 'Number unformatted display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.uri_link:
   type: entity_field_view_display_base
   label: 'URI as link display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.timestamp_ago:
   type: entity_field_view_display_base
   label: 'Timestamp ago display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
diff --git a/core/modules/comment/config/schema/comment.schema.yml b/core/modules/comment/config/schema/comment.schema.yml
index b5bcd86..f27f81a 100644
--- a/core/modules/comment/config/schema/comment.schema.yml
+++ b/core/modules/comment/config/schema/comment.schema.yml
@@ -3,22 +3,10 @@
 entity_view_display.field.comment_default:
   type: entity_field_view_display_base
   label: 'Comment display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.comment_default:
   type: entity_field_form_display_base
   label: 'Comment display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 action.configuration.comment_publish_action:
   type: action_configuration_default
diff --git a/core/modules/datetime/config/schema/datetime.schema.yml b/core/modules/datetime/config/schema/datetime.schema.yml
index 58e4cc6..3086164 100644
--- a/core/modules/datetime/config/schema/datetime.schema.yml
+++ b/core/modules/datetime/config/schema/datetime.schema.yml
@@ -41,12 +41,6 @@ entity_view_display.field.datetime_default:
 entity_view_display.field.datetime_plain:
   type: entity_field_view_display_base
   label: 'Datetime plain display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.datetime_datelist:
   type: entity_field_form_display_base
@@ -69,9 +63,3 @@ entity_form_display.field.datetime_datelist:
 entity_form_display.field.datetime_default:
   type: entity_field_form_display_base
   label: 'Datetime default display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
diff --git a/core/modules/datetime/src/Tests/DateTimeFieldTest.php b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
index 281e78c..8285a2b 100644
--- a/core/modules/datetime/src/Tests/DateTimeFieldTest.php
+++ b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\field\Tests\FieldItemTestBase;
 use Drupal\simpletest\WebTestBase;
 use Drupal\Core\Datetime\DrupalDateTime;
 
@@ -17,7 +18,7 @@
  *
  * @group datetime
  */
-class DateTimeFieldTest extends WebTestBase {
+class DateTimeFieldTest extends FieldItemTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/entity_reference/config/schema/entity_reference.schema.yml b/core/modules/entity_reference/config/schema/entity_reference.schema.yml
index 5404963..22561c9 100644
--- a/core/modules/entity_reference/config/schema/entity_reference.schema.yml
+++ b/core/modules/entity_reference/config/schema/entity_reference.schema.yml
@@ -55,12 +55,6 @@ entity_view_display.field.entity_reference_entity_view:
 entity_view_display.field.entity_reference_entity_id:
   type: entity_field_view_display_base
   label: 'Entity reference entity ID display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.entity_reference_label:
   type: entity_field_view_display_base
diff --git a/core/modules/field/src/Tests/Email/EmailFieldTest.php b/core/modules/field/src/Tests/Email/EmailFieldTest.php
index 2ce3c46..552cad2 100644
--- a/core/modules/field/src/Tests/Email/EmailFieldTest.php
+++ b/core/modules/field/src/Tests/Email/EmailFieldTest.php
@@ -8,14 +8,14 @@
 namespace Drupal\field\Tests\Email;
 
 use Drupal\Component\Utility\Unicode;
-use Drupal\simpletest\WebTestBase;
+use Drupal\field\Tests\FieldItemTestBase;
 
 /**
  * Tests email field functionality.
  *
  * @group field
  */
-class EmailFieldTest extends WebTestBase {
+class EmailFieldTest extends FieldItemTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/field/src/Tests/FieldItemTestBase.php b/core/modules/field/src/Tests/FieldItemTestBase.php
new file mode 100644
index 0000000..1ae1737
--- /dev/null
+++ b/core/modules/field/src/Tests/FieldItemTestBase.php
@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\field\Tests\FieldItemTestBase.
+ */
+
+namespace Drupal\field\Tests;
+
+use Drupal\simpletest\WebTestBase;
+use Drupal\config\Tests\SchemaCheckTestTrait;
+
+class FieldItemTestBase extends WebTestBase {
+
+  use SchemaCheckTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function tearDown() {
+    // Assert schemas for all entity view and form displays.
+    $names = array_merge(
+      $this->container->get('config.storage')->listAll('core.entity_view_display.'),
+      $this->container->get('config.storage')->listAll('core.entity_form_display.')
+    );
+
+    $factory = $this->container->get('config.factory');
+    /** @var \Drupal\Core\Config\TypedConfigManagerInterface $typed_config */
+    $typed_config = $this->container->get('config.typed');
+    foreach ($names as $name) {
+      $config = $factory->get($name);
+      $this->assertConfigSchema($typed_config, $name, $config->get());
+    }
+
+    parent::tearDown();
+  }
+
+}
diff --git a/core/modules/field/src/Tests/Number/NumberFieldTest.php b/core/modules/field/src/Tests/Number/NumberFieldTest.php
index ca1fbb0..a1abf41 100644
--- a/core/modules/field/src/Tests/Number/NumberFieldTest.php
+++ b/core/modules/field/src/Tests/Number/NumberFieldTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\field\Tests\Number;
 
 use Drupal\Component\Utility\Unicode;
+use Drupal\field\Tests\FieldItemTestBase;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -15,7 +16,7 @@
  *
  * @group field
  */
-class NumberFieldTest extends WebTestBase {
+class NumberFieldTest extends FieldItemTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/file/config/schema/file.schema.yml b/core/modules/file/config/schema/file.schema.yml
index cd21f38..0babe38 100644
--- a/core/modules/file/config/schema/file.schema.yml
+++ b/core/modules/file/config/schema/file.schema.yml
@@ -70,43 +70,18 @@ field.file.field_settings:
 entity_view_display.field.file_default:
   type: entity_field_view_display_base
   label: 'Generic file format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.file_rss_enclosure:
   type: entity_field_view_display_base
   label: 'RSS enclosure format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.file_table:
   type: entity_field_view_display_base
   label: 'Table of files format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.file_url_plain:
   type: entity_field_view_display_base
   label: 'URL to file format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
-
 
 entity_form_display.field.file_generic:
   type: entity_field_form_display_base
diff --git a/core/modules/image/config/schema/image.schema.yml b/core/modules/image/config/schema/image.schema.yml
index f0db0d5..33e8a90 100644
--- a/core/modules/image/config/schema/image.schema.yml
+++ b/core/modules/image/config/schema/image.schema.yml
@@ -137,12 +137,6 @@ field.image.value:
 entity_view_display.field.image:
   type: entity_field_view_display_base
   label: 'Image field display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Format settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.image_image:
   type: entity_field_form_display_base
diff --git a/core/modules/image/src/Tests/ImageFieldTestBase.php b/core/modules/image/src/Tests/ImageFieldTestBase.php
index 33e7fc1..554954b 100644
--- a/core/modules/image/src/Tests/ImageFieldTestBase.php
+++ b/core/modules/image/src/Tests/ImageFieldTestBase.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\image\Tests;
 
+use Drupal\field\Tests\FieldItemTestBase;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -25,7 +26,7 @@
 /**
  * This class provides methods specifically for testing Image's field handling.
  */
-abstract class ImageFieldTestBase extends WebTestBase {
+abstract class ImageFieldTestBase extends FieldItemTestBase {
 
   /**
    * Modules to enable.
diff --git a/core/modules/options/config/schema/options.schema.yml b/core/modules/options/config/schema/options.schema.yml
index 03cb81f..f0d444a 100644
--- a/core/modules/options/config/schema/options.schema.yml
+++ b/core/modules/options/config/schema/options.schema.yml
@@ -114,39 +114,15 @@ field.list_string.value:
 entity_view_display.field.list_default:
   type: entity_field_view_display_base
   label: 'Options list default display settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.list_key:
   type: entity_field_view_display_base
   label: 'Key format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.options_buttons:
   type: entity_field_form_display_base
   label: 'Check boxes/radio buttons format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.options_select:
   type: entity_field_form_display_base
   label: 'Select list format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
diff --git a/core/modules/path/config/schema/path.schema.yml b/core/modules/path/config/schema/path.schema.yml
index f595e4b..ebed69c 100644
--- a/core/modules/path/config/schema/path.schema.yml
+++ b/core/modules/path/config/schema/path.schema.yml
@@ -3,6 +3,3 @@
 entity_form_display.field.path:
   type: entity_field_form_display_base
   label: 'Link format settings'
-  mapping:
-    settings:
-      type: sequence
diff --git a/core/modules/taxonomy/config/schema/taxonomy.schema.yml b/core/modules/taxonomy/config/schema/taxonomy.schema.yml
index 579f673..e9aed2b 100644
--- a/core/modules/taxonomy/config/schema/taxonomy.schema.yml
+++ b/core/modules/taxonomy/config/schema/taxonomy.schema.yml
@@ -94,12 +94,6 @@ entity_view_display.field.taxonomy_term_reference_rss_category:
 entity_view_display.field.taxonomy_term_reference_link:
   type: entity_field_view_display_base
   label: 'Taxonomy format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_form_display.field.taxonomy_autocomplete:
   type: entity_field_form_display_base
diff --git a/core/modules/text/config/schema/text.schema.yml b/core/modules/text/config/schema/text.schema.yml
index f472aec..f211cbf 100644
--- a/core/modules/text/config/schema/text.schema.yml
+++ b/core/modules/text/config/schema/text.schema.yml
@@ -93,12 +93,6 @@ field.text_with_summary.value:
 entity_view_display.field.text_default:
   type: entity_field_view_display_base
   label: 'Formatted text default display format settings'
-  mapping:
-    settings:
-      type: sequence
-      label: 'Settings'
-      sequence:
-        - type: string
 
 entity_view_display.field.text_summary_or_trimmed:
   type: entity_field_view_display_base