first commit

core/modules/field/tests/modules/field_plugins_test/field_plugins_test.field_type_categories.yml

@@ -0,0 +1,6 @@
+test_category:
+  label: 'Test category'
+  description: 'This is a test field type category.'
+  weight: -10
+  libraries:
+    - field_plugins_test/test_library

core/modules/field/tests/modules/field_plugins_test/field_plugins_test.info.yml

@@ -0,0 +1,12 @@
+name: 'Field Plugins Test'
+type: module
+description: 'Support module for the field and entity display tests.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:text
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_plugins_test/src/Plugin/Field/FieldFormatter/TestTextTrimmedFormatter.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Drupal\field_plugins_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\text\Plugin\Field\FieldFormatter\TextTrimmedFormatter;
+
+/**
+ * Plugin implementation of the 'field_plugins_test_text_formatter' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_plugins_test_text_formatter',
+  label: new TranslatableMarkup('Test Trimmed'),
+  field_types: [
+    'text',
+    'text_long',
+    'text_with_summary',
+  ],
+)]
+class TestTextTrimmedFormatter extends TextTrimmedFormatter {
+}

core/modules/field/tests/modules/field_plugins_test/src/Plugin/Field/FieldWidget/TestTextfieldWidget.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\field_plugins_test\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\text\Plugin\Field\FieldWidget\TextfieldWidget;
+
+/**
+ * Plugin implementation of the 'field_plugins_test_text_widget' widget.
+ */
+#[FieldWidget(
+  id: 'field_plugins_test_text_widget',
+  label: new TranslatableMarkup('Test Text field'),
+  field_types: [
+    'text',
+    'string',
+  ],
+)]
+class TestTextfieldWidget extends TextfieldWidget {
+}

core/modules/field/tests/modules/field_test/field_test.entity.inc

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * @file
+ * Defines an entity type.
+ */
+
+/**
+ * Implements hook_entity_type_alter().
+ */
+function field_test_entity_type_alter(array &$entity_types) {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+  foreach (field_test_entity_info_translatable() as $entity_type => $translatable) {
+    $entity_types[$entity_type]->set('translatable', $translatable);
+  }
+}
+
+/**
+ * Helper function to enable entity translations.
+ */
+function field_test_entity_info_translatable($entity_type_id = NULL, $translatable = NULL) {
+  static $stored_value = [];
+  if (isset($entity_type_id)) {
+    $entity_definition_update_manager = \Drupal::entityDefinitionUpdateManager();
+    $entity_type = $entity_definition_update_manager->getEntityType($entity_type_id);
+    $stored_value[$entity_type_id] = $translatable;
+    if ($translatable != $entity_type->isTranslatable()) {
+      $entity_definition_update_manager->uninstallEntityType($entity_type);
+      $entity_type->set('translatable', $translatable);
+      $entity_definition_update_manager->installEntityType($entity_type);
+    }
+  }
+  return $stored_value;
+}

core/modules/field/tests/modules/field_test/field_test.field.inc

@@ -0,0 +1,62 @@
+<?php
+
+/**
+ * @file
+ * Defines a field type and its formatters and widgets.
+ */
+
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Entity\Exception\FieldStorageDefinitionUpdateForbiddenException;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\field\FieldStorageConfigInterface;
+
+/**
+ * Implements hook_field_widget_info_alter().
+ */
+function field_test_field_widget_info_alter(&$info) {
+  $info['test_field_widget_multiple']['field_types'][] = 'test_field';
+  $info['test_field_widget_multiple']['field_types'][] = 'test_field_with_preconfigured_options';
+  // Add extra widget when needed for tests.
+  // @see \Drupal\field\Tests\FormTest::widgetAlterTest().
+  if ($alter_info = \Drupal::state()->get("field_test.widget_alter_test")) {
+    if ($alter_info['widget'] === 'test_field_widget_multiple_single_value') {
+      $info['test_field_widget_multiple_single_value']['field_types'][] = 'test_field';
+    }
+  }
+}
+
+/**
+ * Implements hook_field_storage_config_update_forbid().
+ */
+function field_test_field_storage_config_update_forbid(FieldStorageConfigInterface $field_storage, FieldStorageConfigInterface $prior_field_storage) {
+  if ($field_storage->getType() == 'test_field' && $field_storage->getSetting('unchangeable') != $prior_field_storage->getSetting('unchangeable')) {
+    throw new FieldStorageDefinitionUpdateForbiddenException("field_test 'unchangeable' setting cannot be changed'");
+  }
+}
+
+/**
+ * Sample 'default value' callback.
+ */
+function field_test_default_value(FieldableEntityInterface $entity, FieldDefinitionInterface $definition) {
+  return [['value' => 99]];
+}
+
+/**
+ * Implements hook_entity_field_access().
+ */
+function field_test_entity_field_access($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, ?FieldItemListInterface $items = NULL) {
+  if ($field_definition->getName() == "field_no_{$operation}_access") {
+    return AccessResult::forbidden();
+  }
+
+  // Only grant view access to test_view_field fields when the user has
+  // 'view test_view_field content' permission.
+  if ($field_definition->getName() == 'test_view_field' && $operation == 'view') {
+    return AccessResult::forbiddenIf(!$account->hasPermission('view test_view_field content'))->cachePerPermissions();
+  }
+
+  return AccessResult::allowed();
+}

core/modules/field/tests/modules/field_test/field_test.field_type_categories.yml

@@ -0,0 +1,3 @@
+field_test_descriptions:
+  label: 'Field Test'
+  description: 'Fields for testing descriptions.'

core/modules/field/tests/modules/field_test/field_test.info.yml

@@ -0,0 +1,12 @@
+name: 'Field API Test'
+type: module
+description: 'Support module for the Field API tests.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:entity_test
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_test/field_test.module

@@ -0,0 +1,277 @@
+<?php
+
+/**
+ * @file
+ * Helper module for the Field API tests.
+ *
+ * The module defines
+ * - a field type and its formatters and widgets (field_test.field.inc)
+ * - a field storage backend (field_test.storage.inc)
+ *
+ * The main field_test.module file implements generic hooks and provides some
+ * test helper functions
+ */
+
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\Query\QueryInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\field\FieldStorageConfigInterface;
+
+require_once __DIR__ . '/field_test.entity.inc';
+require_once __DIR__ . '/field_test.field.inc';
+
+/**
+ * Store and retrieve keyed data for later verification by unit tests.
+ *
+ * This function is a simple in-memory key-value store with the
+ * distinction that it stores all values for a given key instead of
+ * just the most recently set value. field_test module hooks call
+ * this function to record their arguments, keyed by hook name. The
+ * unit tests later call this function to verify that the correct
+ * hooks were called and were passed the correct arguments.
+ *
+ * This function ignores all calls until the first time it is called
+ * with $key of NULL. Each time it is called with $key of NULL, it
+ * erases all previously stored data from its internal cache, but also
+ * returns the previously stored data to the caller. A typical usage
+ * scenario is:
+ *
+ * @code
+ *   // calls to field_test_memorize() here are ignored
+ *
+ *   // turn on memorization
+ *   field_test_memorize();
+ *
+ *   // call some Field API functions that invoke field_test hooks
+ *   FieldStorageConfig::create($field_definition)->save();
+ *
+ *   // retrieve and reset the memorized hook call data
+ *   $mem = field_test_memorize();
+ *
+ *   // make sure hook_field_storage_config_create() is invoked correctly
+ *   assertEquals(1, count($mem['field_test_field_storage_config_create']));
+ *   assertEquals([$field], $mem['field_test_field_storage_config_create'][0]);
+ * @endcode
+ *
+ * @param $key
+ *   The key under which to store to $value, or NULL as described above.
+ * @param $value
+ *   A value to store for $key.
+ *
+ * @return array|null
+ *   An array mapping each $key to an array of each $value passed in
+ *   for that key.
+ */
+function field_test_memorize($key = NULL, $value = NULL) {
+  static $memorize;
+
+  if (!isset($key)) {
+    $return = $memorize;
+    $memorize = [];
+    return $return;
+  }
+  if (is_array($memorize)) {
+    $memorize[$key][] = $value;
+  }
+}
+
+/**
+ * Memorize calls to field_test_field_storage_config_create().
+ */
+function field_test_field_storage_config_create(FieldStorageConfigInterface $field_storage) {
+  $args = func_get_args();
+  field_test_memorize(__FUNCTION__, $args);
+}
+
+/**
+ * Implements hook_entity_display_build_alter().
+ */
+function field_test_entity_display_build_alter(&$output, $context) {
+  $display_options = $context['display']->getComponent('test_field');
+  if (isset($display_options['settings']['alter'])) {
+    $output['test_field'][] = ['#markup' => 'field_test_entity_display_build_alter'];
+  }
+
+  if (isset($output['test_field'])) {
+    $output['test_field'][] = ['#markup' => 'entity language is ' . $context['entity']->language()->getId()];
+  }
+}
+
+/**
+ * Implements hook_field_widget_single_element_form_alter().
+ */
+function field_test_field_widget_single_element_form_alter(&$element, FormStateInterface $form_state, $context) {
+  // Set a message if this is for the form displayed to set default value for
+  // the field.
+  if ($context['default']) {
+    \Drupal::messenger()
+      ->addStatus('From hook_field_widget_single_element_form_alter(): Default form is true.');
+  }
+}
+
+/**
+ * Implements hook_field_widget_complete_form_alter().
+ */
+function field_test_field_widget_complete_form_alter(array &$field_widget_complete_form, FormStateInterface $form_state, array $context) {
+  _field_test_alter_widget("hook_field_widget_complete_form_alter", $field_widget_complete_form, $form_state, $context);
+}
+
+/**
+ * Implements hook_field_widget_complete_WIDGET_TYPE_form_alter().
+ */
+function field_test_field_widget_complete_test_field_widget_multiple_form_alter(array &$field_widget_complete_form, FormStateInterface $form_state, array $context) {
+  _field_test_alter_widget("hook_field_widget_complete_WIDGET_TYPE_form_alter", $field_widget_complete_form, $form_state, $context);
+}
+
+/**
+ * Implements hook_field_widget_complete_WIDGET_TYPE_form_alter().
+ */
+function field_test_field_widget_complete_test_field_widget_multiple_single_value_form_alter(array &$field_widget_complete_form, FormStateInterface $form_state, array $context) {
+  _field_test_alter_widget("hook_field_widget_complete_WIDGET_TYPE_form_alter", $field_widget_complete_form, $form_state, $context);
+}
+
+/**
+ * Sets up alterations for widget alter tests.
+ *
+ * @see \Drupal\field\Tests\FormTest::widgetAlterTest()
+ */
+function _field_test_alter_widget($hook, array &$field_widget_complete_form, FormStateInterface $form_state, array $context) {
+  $elements = &$field_widget_complete_form['widget'];
+  // Set a message if this is for the form displayed to set default value for
+  // the field.
+  if ($context['default']) {
+    \Drupal::messenger()->addStatus("From $hook(): Default form is true.");
+  }
+  $alter_info = \Drupal::state()->get("field_test.widget_alter_test");
+  $name = $context['items']->getFieldDefinition()->getName();
+  if (!empty($alter_info) && $hook === $alter_info['hook'] && $name === $alter_info['field_name']) {
+    $elements['#prefix'] = "From $hook(): prefix on $name parent element.";
+    foreach (Element::children($elements) as $delta => $element) {
+      $elements[$delta]['#suffix'] = "From $hook(): suffix on $name child element.";
+    }
+  }
+}
+
+/**
+ * Implements hook_query_TAG_alter() for tag 'efq_table_prefixing_test'.
+ *
+ * @see \Drupal\system\Tests\Entity\EntityFieldQueryTest::testTablePrefixing()
+ */
+function field_test_query_efq_table_prefixing_test_alter(&$query) {
+  // Add an additional join onto the entity base table. This will cause an
+  // exception if the EFQ does not properly prefix the base table.
+  $query->join('entity_test', 'et2', '[%alias].[id] = [entity_test].[id]');
+}
+
+/**
+ * Implements hook_query_TAG_alter() for tag 'efq_metadata_test'.
+ *
+ * @see \Drupal\system\Tests\Entity\EntityQueryTest::testMetaData()
+ */
+function field_test_query_efq_metadata_test_alter(&$query) {
+  field_test_memorize(__FUNCTION__, $query->getMetadata('foo'));
+}
+
+/**
+ * Implements hook_entity_extra_field_info_alter().
+ */
+function field_test_entity_extra_field_info_alter(&$info) {
+  // Remove all extra fields from the 'no_fields' content type;
+  unset($info['node']['no_fields']);
+}
+
+/**
+ * Implements hook_entity_bundle_field_info_alter().
+ */
+function field_test_entity_bundle_field_info_alter(&$fields, EntityTypeInterface $entity_type, $bundle) {
+  if (($field_name = \Drupal::state()->get('field_test_constraint', FALSE)) && $entity_type->id() == 'entity_test' && $bundle == 'entity_test' && !empty($fields[$field_name])) {
+    // Set a property constraint using
+    // \Drupal\Core\Field\FieldConfigInterface::setPropertyConstraints().
+    $fields[$field_name]->setPropertyConstraints('value', [
+      'TestField' => [
+        'value' => -2,
+        'message' => t('%name does not accept the value @value.', ['%name' => $field_name, '@value' => -2]),
+      ],
+    ]);
+
+    // Add a property constraint using
+    // \Drupal\Core\Field\FieldConfigInterface::addPropertyConstraints().
+    $fields[$field_name]->addPropertyConstraints('value', [
+      'Range' => [
+        'min' => 0,
+        'max' => 32,
+      ],
+    ]);
+  }
+}
+
+/**
+ * Implements hook_field_ui_preconfigured_options_alter().
+ */
+function field_test_field_ui_preconfigured_options_alter(array &$options, $field_type) {
+  if ($field_type === 'test_field_with_preconfigured_options') {
+    $options['custom_options']['entity_view_display']['settings'] = [
+      'test_formatter_setting_multiple' => 'altered dummy test string',
+    ];
+  }
+}
+
+/**
+ * Implements hook_field_info_entity_type_ui_definitions_alter().
+ */
+function field_test_field_info_entity_type_ui_definitions_alter(array &$ui_definitions, string $entity_type_id) {
+  if ($entity_type_id === 'node') {
+    $ui_definitions['boolean']['label'] = new TranslatableMarkup('Boolean (overridden by alter)');
+  }
+}
+
+function field_test_entity_reference_selection_alter(array &$definitions): void {
+  if (\Drupal::state()->get('field_test_disable_broken_entity_reference_handler')) {
+    unset($definitions['broken']);
+  }
+}
+
+/**
+ * Implements hook_entity_query_alter().
+ *
+ * @see Drupal\KernelTests\Core\Entity\EntityQueryTest::testAlterHook
+ */
+function field_test_entity_query_alter(QueryInterface $query): void {
+  if ($query->hasTag('entity_query_alter_hook_test')) {
+    $query->condition('id', '5', '<>');
+  }
+}
+
+/**
+ * Implements hook_entity_query_ENTITY_TYPE_alter() for 'entity_test_mulrev'.
+ *
+ * @see Drupal\KernelTests\Core\Entity\EntityQueryTest::testAlterHook
+ */
+function field_test_entity_query_entity_test_mulrev_alter(QueryInterface $query): void {
+  if ($query->hasTag('entity_query_entity_test_mulrev_alter_hook_test')) {
+    $query->condition('id', '7', '<>');
+  }
+}
+
+/**
+ * Implements hook_entity_query_tag__TAG_alter() for 'entity_query_alter_tag_test'.
+ *
+ * @see Drupal\KernelTests\Core\Entity\EntityQueryTest::testAlterHook
+ */
+function field_test_entity_query_tag__entity_query_alter_tag_test_alter(QueryInterface $query): void {
+  $query->condition('id', '13', '<>');
+}
+
+/**
+ * Implements hook_entity_query_tag__ENTITY_TYPE__TAG_alter().
+ *
+ * Entity type is 'entity_test_mulrev' and tag is
+ * 'entity_query_entity_test_mulrev_alter_tag_test'.
+ *
+ * @see Drupal\KernelTests\Core\Entity\EntityQueryTest::testAlterHook
+ */
+function field_test_entity_query_tag__entity_test_mulrev__entity_query_entity_test_mulrev_alter_tag_test_alter(QueryInterface $query): void {
+  $query->condition('id', '15', '<>');
+}

core/modules/field/tests/modules/field_test/field_test.permissions.yml

@@ -0,0 +1,6 @@
+view test_view_field content:
+  title: 'View test field content'
+  description: 'View published test_view_field content.'
+administer field_test content:
+  title: 'Administer field_test content'
+  description: 'Manage field_test content'

core/modules/field/tests/modules/field_test/field_test.routing.yml

@@ -0,0 +1,27 @@
+field_test.entity_nested_form:
+  path: '/test-entity/nested/{entity_1}/{entity_2}'
+  defaults:
+    _title: 'Nested entity form'
+    _form: '\Drupal\field_test\Form\NestedEntityTestForm'
+  options:
+    parameters:
+      entity_1:
+        type: 'entity:entity_test'
+      entity_2:
+        type: 'entity:entity_test'
+  requirements:
+    _permission: 'administer entity_test content'
+
+field_test.entity_constraints_nested_form:
+  path: '/test-entity-constraints/nested/{entity_1}/{entity_2}'
+  defaults:
+    _title: 'Nested entity form'
+    _form: '\Drupal\field_test\Form\NestedEntityTestForm'
+  options:
+    parameters:
+      entity_1:
+        type: 'entity:entity_test_constraints'
+      entity_2:
+        type: 'entity:entity_test_constraints'
+  requirements:
+    _permission: 'administer entity_test content'

core/modules/field/tests/modules/field_test/src/FieldDefaultValueCallbackProvider.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Drupal\field_test;
+
+/**
+ * Helper class for \Drupal\Tests\field\Functional\FieldDefaultValueCallbackTest.
+ */
+class FieldDefaultValueCallbackProvider {
+
+  /**
+   * Helper callback calculating a default value.
+   */
+  public static function calculateDefaultValue() {
+    return [['value' => 'Calculated default value']];
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Form/NestedEntityTestForm.php

@@ -0,0 +1,109 @@
+<?php
+
+namespace Drupal\field_test\Form;
+
+use Drupal\Core\Entity\EntityChangedInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+
+/**
+ * Provides a form for field_test routes.
+ *
+ * @internal
+ */
+class NestedEntityTestForm extends FormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'field_test_entity_nested_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, ?EntityInterface $entity_1 = NULL, ?EntityInterface $entity_2 = NULL) {
+    // First entity.
+    $form_state->set('entity_1', $entity_1);
+    $form_display_1 = EntityFormDisplay::collectRenderDisplay($entity_1, 'default');
+    $form_state->set('form_display_1', $form_display_1);
+    $form_display_1->buildForm($entity_1, $form, $form_state);
+
+    // Second entity.
+    $form_state->set('entity_2', $entity_2);
+    $form_display_2 = EntityFormDisplay::collectRenderDisplay($entity_2, 'default');
+    $form_state->set('form_display_2', $form_display_2);
+    $form['entity_2'] = [
+      '#type' => 'details',
+      '#title' => t('Second entity'),
+      '#tree' => TRUE,
+      '#parents' => ['entity_2'],
+      '#weight' => 50,
+      '#attributes' => ['class' => ['entity-2']],
+    ];
+
+    $form_display_2->buildForm($entity_2, $form['entity_2'], $form_state);
+
+    if ($entity_2 instanceof EntityChangedInterface) {
+      // Changed must be sent to the client, for later overwrite error checking.
+      // @see \Drupal\Tests\field\Functional\NestedFormTest::testNestedEntityFormEntityLevelValidation()
+      $form['entity_2']['changed'] = [
+        '#type' => 'hidden',
+        '#default_value' => $entity_1->getChangedTime(),
+      ];
+    }
+
+    $form['save'] = [
+      '#type' => 'submit',
+      '#value' => t('Save'),
+      '#weight' => 100,
+    ];
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateForm(array &$form, FormStateInterface $form_state) {
+    $entity_1 = $form_state->get('entity_1');
+    /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $form_display_1 */
+    $form_display_1 = $form_state->get('form_display_1');
+    $form_display_1->extractFormValues($entity_1, $form, $form_state);
+    $form_display_1->validateFormValues($entity_1, $form, $form_state);
+
+    $entity_2 = $form_state->get('entity_2');
+    /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $form_display_2 */
+    $form_display_2 = $form_state->get('form_display_2');
+    $extracted = $form_display_2->extractFormValues($entity_2, $form['entity_2'], $form_state);
+    // Extract the values of fields that are not rendered through widgets, by
+    // simply copying from top-level form values. This leaves the fields that
+    // are not being edited within this form untouched.
+    // @see \Drupal\Tests\field\Functional\NestedFormTest::testNestedEntityFormEntityLevelValidation()
+    foreach ($form_state->getValues()['entity_2'] as $name => $values) {
+      if ($entity_2->hasField($name) && !isset($extracted[$name])) {
+        $entity_2->set($name, $values);
+      }
+    }
+    $form_display_2->validateFormValues($entity_2, $form['entity_2'], $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    /** @var \Drupal\Core\Entity\EntityInterface $entity_1 */
+    $entity_1 = $form_state->get('entity_1');
+    $entity_1->save();
+
+    /** @var \Drupal\Core\Entity\EntityInterface $entity_2 */
+    $entity_2 = $form_state->get('entity_2');
+    $entity_2->save();
+
+    $this->messenger()->addStatus($this->t('test_entities @id_1 and @id_2 have been updated.', ['@id_1' => $entity_1->id(), '@id_2' => $entity_2->id()]));
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldApplicableFormatter.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_test_applicable' formatter.
+ *
+ * It is applicable to test_field fields unless their name is 'deny_applicable'.
+ */
+#[FieldFormatter(
+  id: 'field_test_applicable',
+  label: new TranslatableMarkup('Applicable'),
+  description: new TranslatableMarkup('Applicable formatter'),
+  field_types: [
+    'test_field',
+  ],
+  weight: 15,
+)]
+class TestFieldApplicableFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function isApplicable(FieldDefinitionInterface $field_definition) {
+    return $field_definition->getName() != 'deny_applicable';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    return ['#markup' => 'Nothing to see here'];
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldDefaultFormatter.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_test_default' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_test_default',
+  label: new TranslatableMarkup('Default'),
+  description: new TranslatableMarkup('Default formatter'),
+  field_types: [
+    'test_field',
+    'test_field_with_preconfigured_options',
+  ],
+  weight: 1,
+)]
+class TestFieldDefaultFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_formatter_setting' => 'dummy test string',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['test_formatter_setting'] = [
+      '#title' => $this->t('Setting'),
+      '#type' => 'textfield',
+      '#size' => 20,
+      '#default_value' => $this->getSetting('test_formatter_setting'),
+      '#required' => TRUE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $summary[] = $this->t('@setting: @value', ['@setting' => 'test_formatter_setting', '@value' => $this->getSetting('test_formatter_setting')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    foreach ($items as $delta => $item) {
+      $elements[$delta] = ['#markup' => $this->getSetting('test_formatter_setting') . '|' . $item->value];
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldEmptyFormatter.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_empty_test' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_empty_test',
+  label: new TranslatableMarkup('Field empty test'),
+  field_types: [
+    'test_field',
+  ],
+  weight: -5,
+)]
+class TestFieldEmptyFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_empty_string' => '**EMPTY FIELD**',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    if ($items->isEmpty()) {
+      // For fields with no value, just add the configured "empty" value.
+      $elements[0] = ['#markup' => $this->getSetting('test_empty_string')];
+    }
+    else {
+      foreach ($items as $delta => $item) {
+        // This formatter only needs to output raw for testing.
+        $elements[$delta] = ['#markup' => $item->value];
+      }
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldEmptySettingFormatter.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_empty_setting' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_empty_setting',
+  label: new TranslatableMarkup('Field empty setting'),
+  field_types: [
+    'test_field',
+  ],
+  weight: -1,
+)]
+class TestFieldEmptySettingFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'field_empty_setting' => '',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['field_empty_setting'] = [
+      '#title' => $this->t('Setting'),
+      '#type' => 'textfield',
+      '#size' => 20,
+      '#default_value' => $this->getSetting('field_empty_setting'),
+      '#required' => TRUE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $setting = $this->getSetting('field_empty_setting');
+    if (!empty($setting)) {
+      $summary[] = $this->t('Default empty setting now has a value.');
+    }
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    if (!empty($items)) {
+      foreach ($items as $delta => $item) {
+        $elements[$delta] = ['#markup' => $this->getSetting('field_empty_setting')];
+      }
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldMultipleFormatter.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_test_multiple' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_test_multiple',
+  label: new TranslatableMarkup('Multiple'),
+  description: new TranslatableMarkup('Multiple formatter'),
+  field_types: [
+    'test_field',
+    'test_field_with_preconfigured_options',
+  ],
+  weight: 5,
+)]
+class TestFieldMultipleFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_formatter_setting_multiple' => 'dummy test string',
+      'alter' => FALSE,
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['test_formatter_setting_multiple'] = [
+      '#title' => $this->t('Setting'),
+      '#type' => 'textfield',
+      '#size' => 20,
+      '#default_value' => $this->getSetting('test_formatter_setting_multiple'),
+      '#required' => TRUE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $summary[] = $this->t('@setting: @value', ['@setting' => 'test_formatter_setting_multiple', '@value' => $this->getSetting('test_formatter_setting_multiple')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    if (!empty($items)) {
+      $array = [];
+      foreach ($items as $delta => $item) {
+        $array[] = $delta . ':' . $item->value;
+      }
+      $elements[0] = ['#markup' => $this->getSetting('test_formatter_setting_multiple') . '|' . implode('|', $array)];
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldNoSettingsFormatter.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_no_settings' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_no_settings',
+  label: new TranslatableMarkup('Field no settings'),
+  field_types: [
+    'test_field',
+  ],
+  weight: -10,
+)]
+class TestFieldNoSettingsFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    foreach ($items as $delta => $item) {
+      // This formatter only needs to output raw for testing.
+      $elements[$delta] = ['#markup' => $item->value];
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldFormatter/TestFieldPrepareViewFormatter.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\Attribute\FieldFormatter;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'field_test_with_prepare_view' formatter.
+ */
+#[FieldFormatter(
+  id: 'field_test_with_prepare_view',
+  label: new TranslatableMarkup('With prepare step'),
+  description: new TranslatableMarkup('Tests prepareView() method'),
+  field_types: [
+    'test_field',
+  ],
+  weight: 10,
+)]
+class TestFieldPrepareViewFormatter extends FormatterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_formatter_setting_additional' => 'dummy test string',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['test_formatter_setting_additional'] = [
+      '#title' => $this->t('Setting'),
+      '#type' => 'textfield',
+      '#size' => 20,
+      '#default_value' => $this->getSetting('test_formatter_setting_additional'),
+      '#required' => TRUE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $summary[] = $this->t('@setting: @value', ['@setting' => 'test_formatter_setting_additional', '@value' => $this->getSetting('test_formatter_setting_additional')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function prepareView(array $entities_items) {
+    foreach ($entities_items as $items) {
+      foreach ($items as $item) {
+        // Don't add anything on empty values.
+        if (!$item->isEmpty()) {
+          $item->additional_formatter_value = $item->value + 1;
+        }
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    foreach ($items as $delta => $item) {
+      $elements[$delta] = ['#markup' => $this->getSetting('test_formatter_setting_additional') . '|' . $item->value . '|' . $item->additional_formatter_value];
+    }
+
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/HiddenTestItem.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines the 'hidden_test' entity field item.
+ */
+#[FieldType(
+  id: "hidden_test_field",
+  label: new TranslatableMarkup("Hidden from UI test field"),
+  description: new TranslatableMarkup("Dummy hidden field type used for tests."),
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default",
+  no_ui: TRUE
+)]
+class HiddenTestItem extends TestItem {
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestItem.php

@@ -0,0 +1,180 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\Field\FieldItemBase;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\TypedData\DataDefinition;
+
+/**
+ * Defines the 'test_field' entity field item.
+ */
+#[FieldType(
+  id: "test_field",
+  label: new TranslatableMarkup("Test field"),
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default"
+)]
+class TestItem extends FieldItemBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultStorageSettings() {
+    return [
+      'test_field_storage_setting' => 'dummy test string',
+      'changeable' => 'a changeable field storage setting',
+      'unchangeable' => 'an unchangeable field storage setting',
+      'translatable_storage_setting' => 'a translatable field storage setting',
+    ] + parent::defaultStorageSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultFieldSettings() {
+    return [
+      'test_field_setting' => 'dummy test string',
+      'translatable_field_setting' => 'a translatable field setting',
+    ] + parent::defaultFieldSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
+    $properties['value'] = DataDefinition::create('integer')
+      ->setLabel(new TranslatableMarkup('Test integer value'))
+      ->setRequired(TRUE);
+
+    return $properties;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function schema(FieldStorageDefinitionInterface $field_definition) {
+    return [
+      'columns' => [
+        'value' => [
+          'type' => 'int',
+          'size' => 'medium',
+        ],
+      ],
+      'indexes' => [
+        'value' => ['value'],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function storageSettingsForm(array &$form, FormStateInterface $form_state, $has_data) {
+    $form['cardinality_container'][] = [
+      '#type' => 'html_tag',
+      '#tag' => 'p',
+      '#value' => 'Greetings from ' . __METHOD__,
+    ];
+    $element = [];
+    $element['test_field_storage_setting'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Field test field storage setting'),
+      '#default_value' => $this->getSetting('test_field_storage_setting'),
+      '#required' => FALSE,
+      '#description' => $this->t('A dummy form element to simulate field storage setting.'),
+    ];
+
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fieldSettingsForm(array $form, FormStateInterface $form_state) {
+    $element = [];
+    $element['test_field_setting'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Field test field setting'),
+      '#default_value' => $this->getSetting('test_field_setting'),
+      '#required' => FALSE,
+      '#description' => $this->t('A dummy form element to simulate field setting.'),
+    ];
+
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete() {
+    // Reports that delete() method is executed for testing purposes.
+    field_test_memorize('field_test_field_delete', [$this->getEntity()]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstraints() {
+    $constraint_manager = \Drupal::typedDataManager()->getValidationConstraintManager();
+    $constraints = parent::getConstraints();
+
+    $constraints[] = $constraint_manager->create('ComplexData', [
+      'value' => [
+        'TestField' => [
+          'value' => -1,
+          'message' => $this->t('%name does not accept the value @value.', ['%name' => $this->getFieldDefinition()->getLabel(), '@value' => -1]),
+        ],
+      ],
+    ]);
+
+    return $constraints;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isEmpty() {
+    return empty($this->value);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function storageSettingsToConfigData(array $settings) {
+    $settings['config_data_from_storage_setting'] = 'TRUE';
+    unset($settings['storage_setting_from_config_data']);
+    return $settings;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function storageSettingsFromConfigData(array $settings) {
+    $settings['storage_setting_from_config_data'] = 'TRUE';
+    unset($settings['config_data_from_storage_setting']);
+    return $settings;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function fieldSettingsToConfigData(array $settings) {
+    $settings['config_data_from_field_setting'] = 'TRUE';
+    unset($settings['field_setting_from_config_data']);
+    return $settings;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function fieldSettingsFromConfigData(array $settings) {
+    $settings['field_setting_from_config_data'] = 'TRUE';
+    unset($settings['config_data_from_field_setting']);
+    return $settings;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestItemWithDependencies.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines the 'test_field_with_dependencies' entity field item.
+ */
+#[FieldType(
+  id: "test_field_with_dependencies",
+  label: new TranslatableMarkup("Test field with dependencies"),
+  description: new TranslatableMarkup("Dummy field type used for tests."),
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default",
+  config_dependencies: [
+    "module" => ["system"],
+  ]
+)]
+class TestItemWithDependencies extends TestItem {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function calculateDependencies(FieldDefinitionInterface $field_definition) {
+    return ['content' => ['node:article:uuid']];
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestItemWithMultipleDescriptions.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines the 'test_field_with_multiple_descriptions' entity field item.
+ */
+#[FieldType(
+  id: "test_field_with_multiple_descriptions",
+  label: new TranslatableMarkup("Test field (multiple descriptions"),
+  description: [
+    new TranslatableMarkup("This multiple line description needs to use an array"),
+    new TranslatableMarkup("This second line contains important information"),
+  ],
+  category: "field_test_descriptions",
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default"
+)]
+class TestItemWithMultipleDescriptions extends TestItem {
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestItemWithPreconfiguredOptions.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Field\PreconfiguredFieldUiOptionsInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines the 'test_field_with_preconfigured_options' entity field item.
+ */
+#[FieldType(
+  id: "test_field_with_preconfigured_options",
+  label: new TranslatableMarkup("Test field with preconfigured options"),
+  description: new TranslatableMarkup("Dummy field type used for tests."),
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default"
+)]
+class TestItemWithPreconfiguredOptions extends TestItem implements PreconfiguredFieldUiOptionsInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getPreconfiguredOptions() {
+    return [
+      'custom_options' => [
+        'label' => new TranslatableMarkup('All custom options'),
+        'field_storage_config' => [
+          'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+          'settings' => [
+            'test_field_storage_setting' => 'preconfigured_storage_setting',
+          ],
+        ],
+        'field_config' => [
+          'required' => TRUE,
+          'settings' => [
+            'test_field_setting' => 'preconfigured_field_setting',
+          ],
+        ],
+        'entity_form_display' => [
+          'type' => 'test_field_widget_multiple',
+        ],
+        'entity_view_display' => [
+          'type' => 'field_test_multiple',
+        ],
+      ],
+    ];
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestItemWithSingleDescription.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines the 'test_field_with_single_description' entity field item.
+ */
+#[FieldType(
+  id: "test_field_with_single_description",
+  label: new TranslatableMarkup("Test field (single description"),
+  description: new TranslatableMarkup("This one-line field description is important for testing"),
+  category: "field_test_descriptions",
+  default_widget: "test_field_widget",
+  default_formatter: "field_test_default"
+)]
+class TestItemWithSingleDescription extends TestItem {
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldType/TestObjectItem.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\Attribute\FieldType;
+use Drupal\Core\Field\FieldItemBase;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\TypedData\DataDefinition;
+
+/**
+ * Defines the 'test_object_field' entity field item.
+ */
+#[FieldType(
+  id: "test_object_field",
+  label: new TranslatableMarkup("Test object field"),
+  description: new TranslatableMarkup("Test field type that has an object to test serialization"),
+  default_widget: "test_object_field_widget",
+  default_formatter: "object_field_test_default"
+)]
+class TestObjectItem extends FieldItemBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
+    $properties['value'] = DataDefinition::create('any')
+      ->setLabel(t('Value'))
+      ->setRequired(TRUE);
+
+    return $properties;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function schema(FieldStorageDefinitionInterface $field_definition) {
+    return [
+      'columns' => [
+        'value' => [
+          'description' => 'The object item value.',
+          'type' => 'blob',
+          'not null' => TRUE,
+          'serialize' => TRUE,
+        ],
+      ],
+    ];
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidget.php

@@ -0,0 +1,118 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\WidgetBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Symfony\Component\Validator\ConstraintViolationInterface;
+
+/**
+ * Plugin implementation of the 'test_field_widget' widget.
+ */
+#[FieldWidget(
+  id: 'test_field_widget',
+  label: new TranslatableMarkup('Test widget'),
+  field_types: [
+    'field_test',
+    'test_field',
+    'hidden_test_field',
+    'test_field_with_preconfigured_options',
+  ],
+  weight: -10,
+)]
+class TestFieldWidget extends WidgetBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_widget_setting' => 'dummy test string',
+      'role' => 'anonymous',
+      'role2' => 'anonymous',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['test_widget_setting'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Field test field widget setting'),
+      '#description' => $this->t('A dummy form element to simulate field widget setting.'),
+      '#default_value' => $this->getSetting('test_widget_setting'),
+      '#required' => FALSE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $summary[] = $this->t('@setting: @value', ['@setting' => 'test_widget_setting', '@value' => $this->getSetting('test_widget_setting')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
+    $element += [
+      '#type' => 'textfield',
+      '#default_value' => $items[$delta]->value ?? '',
+    ];
+    return ['value' => $element];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+    return $element['value'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function calculateDependencies() {
+    $dependencies = parent::calculateDependencies();
+
+    foreach (['role', 'role2'] as $setting) {
+      if (!empty($role_id = $this->getSetting($setting))) {
+        // Create a dependency on the role config entity referenced in settings.
+        $dependencies['config'][] = "user.role.$role_id";
+      }
+    }
+
+    return $dependencies;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onDependencyRemoval(array $dependencies) {
+    $changed = parent::onDependencyRemoval($dependencies);
+
+    // Only the setting 'role' is resolved here. When the dependency related to
+    // this setting is removed, is expected that the widget component will be
+    // update accordingly in the display entity. The 'role2' setting is
+    // deliberately left out from being updated. When the dependency
+    // corresponding to this setting is removed, is expected that the widget
+    // component will be disabled in the display entity.
+    if (!empty($role_id = $this->getSetting('role'))) {
+      if (!empty($dependencies['config']["user.role.$role_id"])) {
+        $this->setSetting('role', 'anonymous');
+        $changed = TRUE;
+      }
+    }
+
+    return $changed;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultilingual.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'test_field_widget_multilingual' widget.
+ */
+#[FieldWidget(
+  id: 'test_field_widget_multilingual',
+  label: new TranslatableMarkup('Test widget - multilingual'),
+  field_types: ['test_field'],
+)]
+class TestFieldWidgetMultilingual extends TestFieldWidget {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(FieldItemListInterface $items, array &$form, FormStateInterface $form_state, $get_delta = NULL) {
+    $elements = parent::form($items, $form, $form_state, $get_delta);
+    $elements['#multilingual'] = TRUE;
+    return $elements;
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultiple.php

@@ -0,0 +1,113 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\WidgetBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Symfony\Component\Validator\ConstraintViolationInterface;
+
+/**
+ * Plugin implementation of the 'test_field_widget_multiple' widget.
+ *
+ * The 'field_types' entry is left empty, and is populated through
+ * hook_field_widget_info_alter().
+ *
+ * @see field_test_field_widget_info_alter()
+ */
+#[FieldWidget(
+  id: 'test_field_widget_multiple',
+  label: new TranslatableMarkup('Test widget - multiple'),
+  multiple_values: TRUE,
+  weight: 10,
+)]
+class TestFieldWidgetMultiple extends WidgetBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'test_widget_setting_multiple' => 'dummy test string',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element['test_widget_setting_multiple'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Field test field widget setting'),
+      '#description' => $this->t('A dummy form element to simulate field widget setting.'),
+      '#default_value' => $this->getSetting('test_widget_setting_multiple'),
+      '#required' => FALSE,
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+    $summary[] = $this->t('@setting: @value', ['@setting' => 'test_widget_setting_multiple', '@value' => $this->getSetting('test_widget_setting_multiple')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
+    $values = [];
+    foreach ($items as $item) {
+      $values[] = $item->value;
+    }
+    $element += [
+      '#type' => 'textfield',
+      '#default_value' => implode(', ', $values),
+      '#element_validate' => [[static::class, 'multipleValidate']],
+    ];
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+    return $element;
+  }
+
+  /**
+   * Element validation helper.
+   */
+  public static function multipleValidate($element, FormStateInterface $form_state) {
+    $values = array_map('trim', explode(',', $element['#value']));
+    $items = [];
+    foreach ($values as $value) {
+      $items[] = ['value' => $value];
+    }
+    $form_state->setValueForElement($element, $items);
+  }
+
+  /**
+   * Test is the widget is applicable to the field definition.
+   *
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
+   *   The field definition that should be checked.
+   *
+   * @return bool
+   *   TRUE if the machine name of the field is not equals to
+   *   field_onewidgetfield, FALSE otherwise.
+   *
+   * @see \Drupal\Tests\field\Functional\EntityReference\EntityReferenceAdminTest::testAvailableFormatters
+   */
+  public static function isApplicable(FieldDefinitionInterface $field_definition) {
+    // Returns FALSE if machine name of the field equals field_onewidgetfield.
+    return $field_definition->getName() != "field_onewidgetfield";
+  }
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultipleSingleValues.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Plugin implementation of the 'test_field_widget_multiple' widget.
+ *
+ * The 'field_types' entry is left empty, and is populated through
+ * hook_field_widget_info_alter().
+ *
+ * @see field_test_field_widget_info_alter()
+ */
+#[FieldWidget(
+  id: 'test_field_widget_multiple_single_value',
+  label: new TranslatableMarkup('Test widget - multiple - single value'),
+  multiple_values: FALSE,
+  weight: 10,
+)]
+class TestFieldWidgetMultipleSingleValues extends TestFieldWidgetMultiple {
+
+}

core/modules/field/tests/modules/field_test/src/Plugin/Validation/Constraint/TestFieldConstraint.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Drupal\field_test\Plugin\Validation\Constraint;
+
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Validation\Attribute\Constraint;
+use Symfony\Component\Validator\Constraints\NotEqualTo;
+
+/**
+ * Checks if a value is not equal.
+ */
+#[Constraint(
+  id: 'TestField',
+  label: new TranslatableMarkup('Test Field', [], ['context' => 'Validation']),
+  type: ['integer']
+)]
+class TestFieldConstraint extends NotEqualTo {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRequiredOptions() {
+    return ['value'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validatedBy() {
+    return '\Symfony\Component\Validator\Constraints\NotEqualToValidator';
+  }
+
+}

core/modules/field/tests/modules/field_test_boolean_access_denied/field_test_boolean_access_denied.info.yml

@@ -0,0 +1,12 @@
+name: 'Boolean field Test'
+type: module
+description: 'Support module for the field and entity display tests.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:field
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_test_boolean_access_denied/field_test_boolean_access_denied.module

@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * @file
+ * Module for testing denying access to boolean fields.
+ */
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Implements hook_entity_field_access().
+ */
+function field_test_boolean_access_denied_entity_field_access($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, ?FieldItemListInterface $items = NULL) {
+  return AccessResult::forbiddenIf($field_definition->getName() === \Drupal::state()->get('field.test_boolean_field_access_field'));
+}

core/modules/field/tests/modules/field_test_config/field_test_config.info.yml

@@ -0,0 +1,10 @@
+name: 'Field API configuration tests'
+type: module
+description: 'Support module for the Field API configuration tests.'
+package: Testing
+# version: VERSION
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_test_config/sync/field.field.entity_test.entity_test.field_test_import_sync.yml

@@ -0,0 +1,17 @@
+id: entity_test.entity_test.field_test_import_sync
+uuid: ea711065-6940-47cd-813d-618f64095481
+langcode: en
+field_name: field_test_import_sync
+entity_type: entity_test
+bundle: entity_test
+label: 'Import from sync'
+description: ''
+required: '0'
+default_value: {  }
+default_value_callback: ''
+settings:
+  allowed_formats: {  }
+field_type: text
+dependencies:
+  config:
+    - field.storage.entity_test.field_test_import_sync

core/modules/field/tests/modules/field_test_config/sync/field.field.entity_test.test_bundle.field_test_import_sync_2.yml

@@ -0,0 +1,17 @@
+id: entity_test.test_bundle.field_test_import_sync_2
+uuid: f07794a2-d7cc-45b6-b40d-13cf021b5552
+langcode: en
+field_name: field_test_import_sync_2
+entity_type: entity_test
+bundle: test_bundle
+label: 'Test import field 2 on test bundle'
+description: ''
+required: '0'
+default_value: {  }
+default_value_callback: ''
+settings:
+  allowed_formats: {  }
+field_type: text
+dependencies:
+  config:
+    - field.storage.entity_test.field_test_import_sync_2

core/modules/field/tests/modules/field_test_config/sync/field.field.entity_test.test_bundle_2.field_test_import_sync_2.yml

@@ -0,0 +1,17 @@
+id: entity_test.test_bundle_2.field_test_import_sync_2
+uuid: 49d6dd19-5097-443d-8f00-fc79525bebce
+langcode: en
+field_name: field_test_import_sync_2
+entity_type: entity_test
+bundle: test_bundle_2
+label: 'Test import field 2 on test bundle 2'
+description: ''
+required: '0'
+default_value: {  }
+default_value_callback: ''
+settings:
+  allowed_formats: {  }
+field_type: text
+dependencies:
+  config:
+    - field.storage.entity_test.field_test_import_sync_2

core/modules/field/tests/modules/field_test_config/sync/field.storage.entity_test.field_test_import_sync.yml

@@ -0,0 +1,21 @@
+id: entity_test.field_test_import_sync
+uuid: 0bf654cc-f14a-4881-b94c-76959e47466b
+langcode: en
+field_name: field_test_import_sync
+entity_type: entity_test
+type: text
+settings:
+  max_length: '255'
+module: text
+locked: '0'
+cardinality: '1'
+translatable: '0'
+indexes:
+  format:
+    - format
+dependencies:
+  module:
+    - entity_test
+    - text
+persist_with_no_fields: false
+custom_storage: false

core/modules/field/tests/modules/field_test_config/sync/field.storage.entity_test.field_test_import_sync_2.yml

@@ -0,0 +1,21 @@
+id: entity_test.field_test_import_sync_2
+uuid: 2165d9aa-9a0c-41a1-be02-2a49f3405c00
+langcode: en
+field_name: field_test_import_sync_2
+entity_type: entity_test
+type: text
+settings:
+  max_length: '255'
+module: text
+locked: '0'
+cardinality: '1'
+translatable: '0'
+indexes:
+  format:
+    - format
+dependencies:
+  module:
+    - entity_test
+    - text
+persist_with_no_fields: false
+custom_storage: false

core/modules/field/tests/modules/field_test_views/field_test_views.info.yml

@@ -0,0 +1,12 @@
+name: 'Field test views'
+type: module
+description: 'Provides default views for views field tests.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:views
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_test_views/test_views/views.view.test_view_field_delete.yml

@@ -0,0 +1,51 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+    - user
+  config:
+    - field.storage.node.field_test
+id: test_view_field_delete
+label: test_view_field_delete
+module: views
+description: ''
+tag: default
+base_table: node
+base_field: nid
+display:
+  default:
+    display_options:
+      access:
+        type: perm
+      fields:
+        nid:
+          field: nid
+          id: nid
+          table: node
+          plugin_id: field
+          entity_type: node
+          entity_field: nid
+        field_test:
+          id: field_test
+          table: node__field_test
+          field: field_test
+          plugin_id: field
+          entity_type: node
+          entity_field: field_test
+      cache:
+        type: tag
+      exposed_form:
+        type: basic
+      pager:
+        type: full
+      query:
+        type: views_query
+      style:
+        type: default
+      row:
+        type: fields
+    display_plugin: default
+    display_title: Default
+    id: default
+    position: 0

core/modules/field/tests/modules/field_test_views/test_views/views.view.test_view_fieldapi.yml

@@ -0,0 +1,72 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+    - user
+id: test_view_fieldapi
+label: test_view_fieldapi
+module: views
+description: ''
+tag: default
+base_table: node_field_data
+base_field: nid
+display:
+  default:
+    display_options:
+      access:
+        type: perm
+      fields:
+        nid:
+          field: nid
+          id: nid
+          table: node_field_data
+          plugin_id: field
+          entity_type: node
+          entity_field: nid
+        field_name_0:
+          id: field_name_0
+          table: node__field_name_0
+          field: field_name_0
+          plugin_id: field
+          entity_type: node
+          entity_field: field_name_0
+        field_name_5:
+          id: field_name_5
+          table: node__field_name_5
+          field: field_name_5
+          plugin_id: field
+          entity_type: node
+          entity_field: field_name_5
+        field_no_view_access:
+          id: field_no_view_access
+          table: node__field_no_view_access
+          field: field_no_view_access
+          plugin_id: field
+          entity_type: node
+          entity_field: field_no_view_access
+      cache:
+        type: tag
+      exposed_form:
+        type: basic
+      pager:
+        type: full
+      query:
+        type: views_query
+      style:
+        type: default
+      row:
+        type: fields
+      sorts:
+        nid:
+          id: nid
+          table: node_field_data
+          field: nid
+          order: ASC
+          plugin_id: field
+          entity_type: node
+          entity_field: nid
+    display_plugin: default
+    display_title: Default
+    id: default
+    position: 0

core/modules/field/tests/modules/field_third_party_test/field_third_party_test.info.yml

@@ -0,0 +1,13 @@
+name: 'Field Third Party Settings Test'
+type: module
+description: 'Support module for the Field API tests.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:entity_test
+  - drupal:field_test
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/modules/field_third_party_test/field_third_party_test.module

@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * @file
+ * Test module.
+ */
+
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FormatterInterface;
+use Drupal\Core\Field\WidgetInterface;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Implements hook_field_widget_third_party_settings_form().
+ */
+function field_third_party_test_field_widget_third_party_settings_form(WidgetInterface $plugin, FieldDefinitionInterface $field_definition, $form_mode, $form, FormStateInterface $form_state) {
+  $element['field_test_widget_third_party_settings_form'] = [
+    '#type' => 'textfield',
+    '#title' => t('3rd party widget settings form'),
+    '#default_value' => $plugin->getThirdPartySetting('field_third_party_test', 'field_test_widget_third_party_settings_form'),
+  ];
+  return $element;
+}
+
+/**
+ * Implements hook_field_widget_settings_summary_alter().
+ */
+function field_third_party_test_field_widget_settings_summary_alter(&$summary, $context) {
+  $summary[] = 'field_test_field_widget_settings_summary_alter';
+  return $summary;
+}
+
+/**
+ * Implements hook_field_formatter_third_party_settings_form().
+ */
+function field_third_party_test_field_formatter_third_party_settings_form(FormatterInterface $plugin, FieldDefinitionInterface $field_definition, $view_mode, $form, FormStateInterface $form_state) {
+  $element['field_test_field_formatter_third_party_settings_form'] = [
+    '#type' => 'textfield',
+    '#title' => t('3rd party formatter settings form'),
+    '#default_value' => $plugin->getThirdPartySetting('field_third_party_test', 'field_test_field_formatter_third_party_settings_form'),
+  ];
+  return $element;
+}
+
+/**
+ * Implements hook_field_formatter_settings_summary_alter().
+ */
+function field_third_party_test_field_formatter_settings_summary_alter(&$summary, $context) {
+  $summary[] = 'field_test_field_formatter_settings_summary_alter';
+  return $summary;
+}

core/modules/field/tests/modules/field_timestamp_test/field_timestamp_test.info.yml

@@ -0,0 +1,13 @@
+name: 'Field Timestamp Test'
+type: module
+description: 'Support module for the Timestamp field item test.'
+package: Testing
+# version: VERSION
+dependencies:
+  - drupal:entity_test
+  - drupal:field
+
+# Information added by Drupal.org packaging script on 2024-07-04
+version: '10.3.1'
+project: 'drupal'
+datestamp: 1720094222

core/modules/field/tests/src/Functional/Boolean/BooleanFieldTest.php

@@ -0,0 +1,250 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Boolean;
+
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests boolean field functionality.
+ *
+ * @group field
+ */
+class BooleanFieldTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'entity_test',
+    'field_ui',
+    'options',
+    'field_test_boolean_access_denied',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * A field to use in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldStorageConfig
+   */
+  protected $fieldStorage;
+
+  /**
+   * The field used in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldConfig
+   */
+  protected $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'administer entity_test form display',
+      'administer entity_test fields',
+    ]));
+  }
+
+  /**
+   * Tests boolean field.
+   */
+  public function testBooleanField(): void {
+    $on = $this->randomMachineName();
+    $off = $this->randomMachineName();
+    $label = $this->randomMachineName();
+
+    // Create a field with settings to validate.
+    $field_name = $this->randomMachineName();
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'boolean',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $label,
+      'required' => TRUE,
+      'settings' => [
+        'on_label' => $on,
+        'off_label' => $off,
+      ],
+    ]);
+    $this->field->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Create a form display for the default form mode.
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'boolean_checkbox',
+      ])
+      ->save();
+    // Create a display for the full view mode.
+    $display_repository->getViewDisplay('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, [
+        'type' => 'boolean',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[value]", '');
+    $this->assertSession()->pageTextContains($this->field->label());
+    $this->assertSession()->responseNotContains($on);
+
+    // Submit and ensure it is accepted.
+    $edit = [
+      "{$field_name}[value]" => 1,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+
+    // Verify that boolean value is displayed.
+    $entity = EntityTest::load($id);
+    $this->drupalGet($entity->toUrl());
+    $this->assertSession()->pageTextContains($on);
+
+    // Test with "On" label option.
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'boolean_checkbox',
+        'settings' => [
+          'display_label' => FALSE,
+        ],
+      ])
+      ->save();
+
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[value]", '');
+    $this->assertSession()->pageTextContains($on);
+    $this->assertSession()->pageTextNotContains($this->field->label());
+
+    // Test if we can change the on label.
+    $on = $this->randomMachineName();
+    $edit = [
+      'settings[on_label]' => $on,
+    ];
+    $this->drupalGet('entity_test/structure/entity_test/fields/entity_test.entity_test.' . $field_name);
+    $this->submitForm($edit, 'Save settings');
+    // Check if we see the updated labels in the creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->pageTextContains($on);
+
+    // Go to the form display page and check if the default settings works as
+    // expected.
+    $fieldEditUrl = 'entity_test/structure/entity_test/form-display';
+    $this->drupalGet($fieldEditUrl);
+
+    // Click on the widget settings button to open the widget settings form.
+    $this->submitForm([], $field_name . "_settings_edit");
+
+    $this->assertSession()->pageTextContains('Use field label instead of the "On" label as the label.');
+
+    // Enable setting.
+    $edit = ['fields[' . $field_name . '][settings_edit_form][settings][display_label]' => 1];
+    $this->submitForm($edit, $field_name . "_plugin_settings_update");
+    $this->submitForm([], 'Save');
+
+    // Go again to the form display page and check if the setting
+    // is stored and has the expected effect.
+    $this->drupalGet($fieldEditUrl);
+    $this->assertSession()->pageTextContains('Use field label: Yes');
+
+    $this->submitForm([], $field_name . "_settings_edit");
+    $this->assertSession()->pageTextContains('Use field label instead of the "On" label as the label.');
+    $this->getSession()->getPage()->hasCheckedField('fields[' . $field_name . '][settings_edit_form][settings][display_label]');
+
+    // Test the boolean field settings.
+    $this->drupalGet('entity_test/structure/entity_test/fields/entity_test.entity_test.' . $field_name);
+    $this->assertSession()->fieldValueEquals('edit-settings-on-label', $on);
+    $this->assertSession()->fieldValueEquals('edit-settings-off-label', $off);
+  }
+
+  /**
+   * Tests field access.
+   */
+  public function testFormAccess(): void {
+    $on = 'boolean_on';
+    $off = 'boolean_off';
+    $label = 'boolean_label';
+    $field_name = 'boolean_name';
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'boolean',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $label,
+      'settings' => [
+        'on_label' => $on,
+        'off_label' => $off,
+      ],
+    ]);
+    $this->field->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Create a form display for the default form mode.
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'boolean_checkbox',
+      ])
+      ->save();
+
+    // Create a display for the full view mode.
+    $display_repository->getViewDisplay('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, [
+        'type' => 'boolean',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldExists("{$field_name}[value]");
+
+    // Should be posted OK.
+    $this->submitForm([], 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+
+    // Tell the test module to disable access to the field.
+    \Drupal::state()->set('field.test_boolean_field_access_field', $field_name);
+    $this->drupalGet('entity_test/add');
+    // Field should not be there anymore.
+    $this->assertSession()->fieldNotExists("{$field_name}[value]");
+    // Should still be able to post the form.
+    $this->submitForm([], 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+  }
+
+}

core/modules/field/tests/src/Functional/Boolean/BooleanFormatterSettingsTest.php

@@ -0,0 +1,140 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Boolean;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the Boolean field formatter settings.
+ *
+ * @group field
+ */
+class BooleanFormatterSettingsTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of the entity bundle that is created in the test.
+   *
+   * @var string
+   */
+  protected $bundle;
+
+  /**
+   * The name of the Boolean field to use for testing.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a content type. Use Node because it has Field UI pages that work.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType(['name' => $type_name, 'type' => $type_name]);
+    $this->bundle = $type->id();
+
+    $admin_user = $this->drupalCreateUser([
+      'access content',
+      'administer content types',
+      'administer node fields',
+      'administer node display',
+      'bypass node access',
+      'administer nodes',
+    ]);
+    $this->drupalLogin($admin_user);
+
+    $this->fieldName = $this->randomMachineName(8);
+
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => 'node',
+      'type' => 'boolean',
+    ]);
+    $field_storage->save();
+
+    $instance = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => $this->bundle,
+      'label' => $this->randomMachineName(),
+    ]);
+    $instance->save();
+
+    \Drupal::service('entity_display.repository')
+      ->getViewDisplay('node', $this->bundle)
+      ->setComponent($this->fieldName, [
+        'type' => 'boolean',
+        'settings' => [],
+      ])
+      ->save();
+  }
+
+  /**
+   * Tests the formatter settings page for the Boolean formatter.
+   */
+  public function testBooleanFormatterSettings(): void {
+    // List the options we expect to see on the settings form. Omit the one
+    // with the Unicode check/x characters, which does not appear to work
+    // well in BrowserTestBase.
+    $options = [
+      'Yes / No',
+      'True / False',
+      'On / Off',
+      'Enabled / Disabled',
+      '1 / 0',
+      'Custom',
+    ];
+
+    // For several different values of the field settings, test that the
+    // options, including default, are shown correctly.
+    $settings = [
+      ['Yes', 'No'],
+      ['On', 'Off'],
+      ['TRUE', 'FALSE'],
+    ];
+
+    $assert_session = $this->assertSession();
+    foreach ($settings as $values) {
+      // Set up the field settings.
+      $this->drupalGet('admin/structure/types/manage/' . $this->bundle . '/fields/node.' . $this->bundle . '.' . $this->fieldName);
+      $this->submitForm([
+        'settings[on_label]' => $values[0],
+        'settings[off_label]' => $values[1],
+      ], 'Save settings');
+
+      // Open the Manage Display page and trigger the field settings form.
+      $this->drupalGet('admin/structure/types/manage/' . $this->bundle . '/display');
+      $this->submitForm([], $this->fieldName . '_settings_edit');
+
+      // Test that the settings options are present in the correct format.
+      foreach ($options as $string) {
+        $assert_session->pageTextContains($string);
+      }
+      $assert_session->pageTextContains("Field settings ({$values[0]} / {$values[1]})");
+
+      // Test that the settings summary are present in the correct format.
+      $this->drupalGet('admin/structure/types/manage/' . $this->bundle . '/display');
+      $this->assertSession()->elementExists('xpath', "//div[contains(@class, 'field-plugin-summary')]");
+      $this->assertSession()->elementTextEquals('xpath', "//div[contains(@class, 'field-plugin-summary')]", "Display: {$values[0]} / {$values[1]}");
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/Email/EmailFieldTest.php

@@ -0,0 +1,128 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Email;
+
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests email field functionality.
+ *
+ * @group field
+ */
+class EmailFieldTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * A field storage to use in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldStorageConfig
+   */
+  protected $fieldStorage;
+
+  /**
+   * The field used in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldConfig
+   */
+  protected $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'administer content types',
+    ]));
+  }
+
+  /**
+   * Tests email field.
+   */
+  public function testEmailField(): void {
+    // Create a field with settings to validate.
+    $field_name = $this->randomMachineName();
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'email',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'bundle' => 'entity_test',
+    ]);
+    $this->field->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Create a form display for the default form mode.
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'email_default',
+        'settings' => [
+          'placeholder' => 'example@example.com',
+        ],
+      ])
+      ->save();
+    // Create a display for the full view mode.
+    $display_repository->getViewDisplay('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, [
+        'type' => 'email_mailto',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->responseContains('placeholder="example@example.com"');
+
+    // Submit a valid email address and ensure it is accepted.
+    $value = 'test@example.com';
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $this->assertSession()->responseContains($value);
+
+    // Verify that a mailto link is displayed.
+    $entity = EntityTest::load($id);
+    $display = $display_repository->getViewDisplay($entity->getEntityTypeId(), $entity->bundle(), 'full');
+    $content = $display->build($entity);
+    $rendered_content = (string) \Drupal::service('renderer')->renderRoot($content);
+    $this->assertStringContainsString('href="mailto:test@example.com"', $rendered_content);
+
+    // Test Email validation message.
+    $this->drupalGet('entity_test/add');
+    $value = 'abc.@in';
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->statusMessageContains("The email address {$value} is not valid. Use the format user@example.com.", 'error');
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAdminTest.php

@@ -0,0 +1,431 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Behat\Mink\Element\NodeElement;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Messenger\MessengerInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\node\Entity\Node;
+use Drupal\taxonomy\Entity\Vocabulary;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\field_ui\Traits\FieldUiTestTrait;
+
+/**
+ * Tests for the administrative UI.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceAdminTest extends BrowserTestBase {
+
+  use FieldUiTestTrait;
+
+  /**
+   * Modules to install.
+   *
+   * Enable path module to ensure that the selection handler does not fail for
+   * entities with a path field.
+   * Enable views_ui module to see the no_view_help text.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'node',
+    'field_ui',
+    'path',
+    'taxonomy',
+    'block',
+    'views_ui',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of the content type created for testing purposes.
+   *
+   * @var string
+   */
+  protected $type;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+
+    // Create a content type, with underscores.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType(['name' => $type_name, 'type' => $type_name]);
+    $this->type = $type->id();
+
+    // Create test user.
+    $admin_user = $this->drupalCreateUser([
+      'access content',
+      'administer node fields',
+      'administer node display',
+      'administer views',
+      'create ' . $type_name . ' content',
+      'edit own ' . $type_name . ' content',
+    ]);
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests the Entity Reference Admin UI.
+   */
+  public function testFieldAdminHandler(): void {
+    $bundle_path = 'admin/structure/types/manage/' . $this->type;
+    // Create a new view and display it as an entity reference.
+    $edit = [
+      'id' => 'node_test_view',
+      'label' => 'Node Test View',
+      'show[wizard_key]' => 'node',
+      'show[sort]' => 'none',
+      'page[create]' => 1,
+      'page[title]' => 'Test Node View',
+      'page[path]' => 'test/node/view',
+      'page[style][style_plugin]' => 'default',
+      'page[style][row_plugin]' => 'fields',
+    ];
+    $this->drupalGet('admin/structure/views/add');
+    $this->submitForm($edit, 'Save and edit');
+    $this->submitForm([], 'Duplicate as Entity Reference');
+    $this->clickLink('Settings');
+    $edit = [
+      'style_options[search_fields][title]' => 'title',
+    ];
+    $this->submitForm($edit, 'Apply');
+
+    // Set sort to NID ascending.
+    $edit = [
+      'name[node_field_data.nid]' => 1,
+    ];
+    $this->drupalGet('admin/structure/views/nojs/add-handler/node_test_view/entity_reference_1/sort');
+    $this->submitForm($edit, 'Add and configure sort criteria');
+    $this->submitForm([], 'Apply');
+
+    $this->drupalGet('admin/structure/views/view/node_test_view/edit/entity_reference_1');
+    $this->submitForm([], 'Save');
+    $this->clickLink('Settings');
+
+    // Create a test entity reference field.
+    $field_name = 'test_entity_ref_field';
+    $this->fieldUIAddNewField($bundle_path, $field_name, 'Test Entity Reference Field', 'field_ui:entity_reference:node', [], [], FALSE);
+
+    // Set to unlimited.
+    $edit = [
+      'field_storage[subform][cardinality]' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ];
+    $this->submitForm($edit, 'Update settings');
+
+    // Add the view to the test field.
+    $edit = [
+      'settings[handler]' => 'views',
+    ];
+    $this->submitForm($edit, 'Change handler');
+    $edit = [
+      'required' => FALSE,
+      'settings[handler_settings][view][view_and_display]' => 'node_test_view:entity_reference_1',
+    ];
+    $this->submitForm($edit, 'Save settings');
+    $this->assertSession()->statusMessageContains("Saved Test Entity Reference Field configuration.", MessengerInterface::TYPE_STATUS);
+    $this->assertFieldExistsOnOverview('Test Entity Reference Field');
+
+    // Create nodes.
+    $node1 = Node::create([
+      'type' => $this->type,
+      'title' => 'Foo Node',
+    ]);
+    $node1->save();
+    $node2 = Node::create([
+      'type' => $this->type,
+      'title' => 'Foo Node',
+    ]);
+    $node2->save();
+
+    // Try to add a new node and fill the entity reference field.
+    $this->drupalGet('node/add/' . $this->type);
+    $field = $this->assertSession()->fieldExists('field_test_entity_ref_field[0][target_id]');
+    $this->assertStringContainsString("/entity_reference_autocomplete/node/views/", $field->getAttribute('data-autocomplete-path'));
+    $target_url = $this->getAbsoluteUrl($field->getAttribute('data-autocomplete-path'));
+    $this->drupalGet($target_url, ['query' => ['q' => 'Foo']]);
+    $this->assertSession()->pageTextContains($node1->getTitle() . ' (' . $node1->id() . ')');
+    $this->assertSession()->pageTextContains($node2->getTitle() . ' (' . $node2->id() . ')');
+
+    // Try to add a new node, fill the entity reference field and submit the
+    // form.
+    $this->drupalGet('node/add/' . $this->type);
+    $this->submitForm([], 'Add another item');
+    $edit = [
+      'title[0][value]' => 'Example',
+      'field_test_entity_ref_field[0][target_id]' => 'Foo Node (' . $node1->id() . ')',
+      'field_test_entity_ref_field[1][target_id]' => 'Foo Node (' . $node2->id() . ')',
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->statusCodeEquals(200);
+
+    $edit = [
+      'title[0][value]' => 'Example',
+      'field_test_entity_ref_field[0][target_id]' => 'Test',
+    ];
+    $this->drupalGet('node/add/' . $this->type);
+    $this->submitForm($edit, 'Save');
+
+    // Assert that entity reference autocomplete field is validated.
+    $this->assertSession()->pageTextContains('There are no content items matching "Test"');
+
+    $edit = [
+      'title[0][value]' => 'Test',
+      'field_test_entity_ref_field[0][target_id]' => $node1->getTitle(),
+    ];
+    $this->drupalGet('node/add/' . $this->type);
+    $this->submitForm($edit, 'Save');
+
+    // Assert the results multiple times to avoid sorting problem of nodes with
+    // the same title.
+    $this->assertSession()->pageTextContains('Multiple content items match this reference;');
+    $this->assertSession()->pageTextContains($node1->getTitle() . ' (' . $node1->id() . ')');
+    $this->assertSession()->pageTextContains($node2->getTitle() . ' (' . $node2->id() . ')');
+    $this->assertSession()->pageTextContains('Specify the one you want by appending the id in parentheses, like "' . $node2->getTitle() . ' (' . $node2->id() . ')' . '".');
+
+    $edit = [
+      'title[0][value]' => 'Test',
+      'field_test_entity_ref_field[0][target_id]' => $node1->getTitle() . ' (' . $node1->id() . ')',
+    ];
+    $this->drupalGet('node/add/' . $this->type);
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->linkExists($node1->getTitle());
+
+    // Tests adding default values to autocomplete widgets.
+    Vocabulary::create(['vid' => 'tags', 'name' => 'tags'])->save();
+    $taxonomy_term_field_name = $this->createEntityReferenceField('taxonomy_term', ['tags']);
+    $field_path = 'node.' . $this->type . '.field_' . $taxonomy_term_field_name;
+    $this->drupalGet($bundle_path . '/fields/' . $field_path);
+    $edit = [
+      'field_storage[subform][cardinality]' => -1,
+    ];
+    $this->submitForm($edit, 'Update settings');
+
+    // Assert that the target bundle handler setting is initially set.
+    $this->assertSession()->checkboxChecked('settings[handler_settings][target_bundles][tags]');
+    // Change the handler to 'views'.
+    $this->submitForm([
+      'settings[handler]' => 'views',
+    ], 'Change handler');
+    $this->assertSession()->fieldValueEquals('settings[handler]', 'views');
+    // Change handler back to 'default'.
+    $this->submitForm([
+      'settings[handler]' => 'default:taxonomy_term',
+    ], 'Change handler');
+    // Assert that changing the handler resets the handler settings.
+    $this->assertSession()->checkboxNotChecked('settings[handler_settings][target_bundles][tags]');
+
+    $term_name = $this->randomString();
+    $result = \Drupal::entityQuery('taxonomy_term')
+      ->condition('name', $term_name)
+      ->condition('vid', 'tags')
+      ->accessCheck(FALSE)
+      ->execute();
+    $this->assertCount(0, $result, "No taxonomy terms exist with the name '$term_name'.");
+    $edit = [
+      'settings[handler_settings][target_bundles][tags]' => TRUE,
+      // This must be set before new entities will be auto-created.
+      'settings[handler_settings][auto_create]' => 1,
+    ];
+    $this->submitForm($edit, 'Save settings');
+    $this->assertFieldExistsOnOverview($taxonomy_term_field_name);
+    $this->drupalGet($bundle_path . '/fields/' . $field_path);
+    $edit = [
+      'set_default_value' => '1',
+      // A term that doesn't yet exist.
+      'default_value_input[field_' . $taxonomy_term_field_name . '][0][target_id]' => $term_name,
+    ];
+    $this->submitForm($edit, 'Save settings');
+    $this->assertFieldExistsOnOverview($taxonomy_term_field_name);
+    // The term should now exist.
+    $result = \Drupal::entityQuery('taxonomy_term')
+      ->condition('name', $term_name)
+      ->condition('vid', 'tags')
+      ->accessCheck(FALSE)
+      ->execute();
+    $this->assertCount(1, $result, 'Taxonomy term was auto created when set as field default.');
+  }
+
+  /**
+   * Tests the formatters for the Entity References.
+   */
+  public function testAvailableFormatters(): void {
+    // Create a new vocabulary.
+    Vocabulary::create(['vid' => 'tags', 'name' => 'tags'])->save();
+
+    // Create entity reference field with taxonomy term as a target.
+    $taxonomy_term_field_name = $this->createEntityReferenceField('taxonomy_term', ['tags']);
+
+    // Create entity reference field with user as a target.
+    $user_field_name = $this->createEntityReferenceField('user');
+
+    // Create entity reference field with node as a target.
+    $node_field_name = $this->createEntityReferenceField('node', [$this->type]);
+
+    // Create entity reference field with date format as a target.
+    $date_format_field_name = $this->createEntityReferenceField('date_format');
+
+    // Display all newly created Entity Reference configuration.
+    $this->drupalGet('admin/structure/types/manage/' . $this->type . '/display');
+
+    // Check for Taxonomy Term select box values.
+    // Test if Taxonomy Term Entity Reference Field has the correct formatters.
+    $this->assertFieldSelectOptions('fields[field_' . $taxonomy_term_field_name . '][type]', [
+      'entity_reference_label',
+      'entity_reference_entity_id',
+      'entity_reference_rss_category',
+      'entity_reference_entity_view',
+    ]);
+
+    // Test if User Reference Field has the correct formatters.
+    // Author should be available for this field.
+    // RSS Category should not be available for this field.
+    $this->assertFieldSelectOptions('fields[field_' . $user_field_name . '][type]', [
+      'author',
+      'entity_reference_entity_id',
+      'entity_reference_entity_view',
+      'entity_reference_label',
+    ]);
+
+    // Test if Node Entity Reference Field has the correct formatters.
+    // RSS Category should not be available for this field.
+    $this->assertFieldSelectOptions('fields[field_' . $node_field_name . '][type]', [
+      'entity_reference_label',
+      'entity_reference_entity_id',
+      'entity_reference_entity_view',
+    ]);
+
+    // Test if Date Format Reference Field has the correct formatters.
+    // RSS Category & Entity View should not be available for this field.
+    // This could be any field without a ViewBuilder.
+    $this->assertFieldSelectOptions('fields[field_' . $date_format_field_name . '][type]', [
+      'entity_reference_label',
+      'entity_reference_entity_id',
+    ]);
+  }
+
+  /**
+   * Tests field settings for an entity reference field.
+   *
+   * The tested entity reference field has multiple target bundles and is set
+   * to auto-create the target entity.
+   */
+  public function testMultipleTargetBundles(): void {
+    /** @var \Drupal\taxonomy\Entity\Vocabulary[] $vocabularies */
+    $vocabularies = [];
+    for ($i = 0; $i < 2; $i++) {
+      $vid = $this->randomMachineName();
+      $vocabularies[$i] = Vocabulary::create([
+        'name' => $this->randomString(),
+        'vid' => $vid,
+      ]);
+      $vocabularies[$i]->save();
+    }
+
+    // Create a new field pointing to the first vocabulary.
+    $field_name = $this->createEntityReferenceField('taxonomy_term', [$vocabularies[0]->id()]);
+    $field_name = "field_$field_name";
+    $field_id = 'node.' . $this->type . '.' . $field_name;
+    $path = 'admin/structure/types/manage/' . $this->type . '/fields/' . $field_id;
+
+    $this->drupalGet($path);
+
+    // Expect that there's no 'auto_create_bundle' selected.
+    $this->assertSession()->fieldNotExists('settings[handler_settings][auto_create_bundle]');
+
+    $edit = [
+      'settings[handler_settings][target_bundles][' . $vocabularies[1]->id() . ']' => TRUE,
+    ];
+    // Enable the second vocabulary as a target bundle.
+    $this->drupalGet($path);
+    $this->submitForm($edit, 'Save settings');
+    $this->drupalGet($path);
+    // Expect a select element with the two vocabularies as options.
+    $this->assertSession()->optionExists('settings[handler_settings][auto_create_bundle]', $vocabularies[0]->id());
+    $this->assertSession()->optionExists('settings[handler_settings][auto_create_bundle]', $vocabularies[1]->id());
+
+    $edit = [
+      'settings[handler_settings][auto_create]' => TRUE,
+      'settings[handler_settings][auto_create_bundle]' => $vocabularies[1]->id(),
+    ];
+    $this->submitForm($edit, 'Save settings');
+
+    /** @var \Drupal\field\Entity\FieldConfig $field_config */
+    $field_config = FieldConfig::load($field_id);
+    // Expect that the target bundle has been saved in the backend.
+    $this->assertEquals($vocabularies[1]->id(), $field_config->getSetting('handler_settings')['auto_create_bundle']);
+
+    // Delete the other bundle. Field config should not be affected.
+    $vocabularies[0]->delete();
+    $field_config = FieldConfig::load($field_id);
+    $this->assertTrue($field_config->getSetting('handler_settings')['auto_create']);
+    $this->assertSame($vocabularies[1]->id(), $field_config->getSetting('handler_settings')['auto_create_bundle']);
+
+    // Delete the bundle set for entity auto-creation. Auto-created settings
+    // should be reset (no auto-creation).
+    $vocabularies[1]->delete();
+    $field_config = FieldConfig::load($field_id);
+    $this->assertFalse($field_config->getSetting('handler_settings')['auto_create']);
+    $this->assertFalse(isset($field_config->getSetting('handler_settings')['auto_create_bundle']));
+  }
+
+  /**
+   * Creates a new Entity Reference fields with a given target type.
+   *
+   * @param string $target_type
+   *   The name of the target type
+   * @param string[] $bundles
+   *   A list of bundle IDs. Defaults to [].
+   *
+   * @return string
+   *   Returns the generated field name
+   */
+  protected function createEntityReferenceField($target_type, $bundles = []) {
+    // Generates a bundle path for the newly created content type.
+    $bundle_path = 'admin/structure/types/manage/' . $this->type;
+
+    // Generate a random field name, must be only lowercase characters.
+    $field_name = $this->randomMachineName();
+
+    $storage_edit = $field_edit = [];
+    $storage_edit['settings[target_type]'] = $target_type;
+    foreach ($bundles as $bundle) {
+      $field_edit['settings[handler_settings][target_bundles][' . $bundle . ']'] = TRUE;
+    }
+
+    $this->fieldUIAddNewField($bundle_path, $field_name, $field_name, 'entity_reference', $storage_edit, $field_edit);
+
+    // Returns the generated field name.
+    return $field_name;
+  }
+
+  /**
+   * Checks if a select element contains the specified options.
+   *
+   * @param string $name
+   *   The field name.
+   * @param array $expected_options
+   *   An array of expected options.
+   *
+   * @internal
+   */
+  protected function assertFieldSelectOptions(string $name, array $expected_options): void {
+    $options = $this->assertSession()->selectExists($name)->findAll('xpath', 'option');
+    array_walk($options, function (NodeElement &$option) {
+      $option = $option->getValue();
+    });
+    $this->assertEqualsCanonicalizing($expected_options, $options);
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php

@@ -0,0 +1,305 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\field\Traits\EntityReferenceFieldCreationTrait;
+use Drupal\taxonomy\Entity\Vocabulary;
+use Drupal\node\Entity\Node;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests creating new entity (e.g. taxonomy-term) from an autocomplete widget.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceAutoCreateTest extends BrowserTestBase {
+
+  use EntityReferenceFieldCreationTrait;
+
+  protected static $modules = ['node', 'taxonomy', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of a content type that will reference $referencedType.
+   *
+   * @var string
+   */
+  protected $referencingType;
+
+  /**
+   * The name of a content type that will be referenced by $referencingType.
+   *
+   * @var string
+   */
+  protected $referencedType;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create "referencing" and "referenced" node types.
+    $referencing = $this->drupalCreateContentType();
+    $this->referencingType = $referencing->id();
+
+    $referenced = $this->drupalCreateContentType();
+    $this->referencedType = $referenced->id();
+
+    FieldStorageConfig::create([
+      'field_name' => 'test_field',
+      'entity_type' => 'node',
+      'translatable' => FALSE,
+      'entity_types' => [],
+      'settings' => [
+        'target_type' => 'node',
+      ],
+      'type' => 'entity_reference',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ])->save();
+
+    FieldConfig::create([
+      'label' => 'Entity reference field',
+      'field_name' => 'test_field',
+      'entity_type' => 'node',
+      'bundle' => $referencing->id(),
+      'settings' => [
+        'handler' => 'default',
+        'handler_settings' => [
+          // Reference a single vocabulary.
+          'target_bundles' => [
+            $referenced->id(),
+          ],
+          // Enable auto-create.
+          'auto_create' => TRUE,
+        ],
+      ],
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getViewDisplay('node', $referencing->id())
+      ->setComponent('test_field')
+      ->save();
+    $display_repository->getFormDisplay('node', $referencing->id(), 'default')
+      ->setComponent('test_field', [
+        'type' => 'entity_reference_autocomplete',
+      ])
+      ->save();
+
+    $account = $this->drupalCreateUser([
+      'access content',
+      "create $this->referencingType content",
+    ]);
+    $this->drupalLogin($account);
+  }
+
+  /**
+   * Tests the autocomplete input element and entity auto-creation.
+   */
+  public function testAutoCreate(): void {
+    $this->drupalGet('node/add/' . $this->referencingType);
+    $target = $this->assertSession()->fieldExists("edit-test-field-0-target-id");
+    $this->assertTrue($target->hasClass("form-autocomplete"));
+
+    $new_title = $this->randomMachineName();
+
+    // Assert referenced node does not exist.
+    $base_query = \Drupal::entityQuery('node')->accessCheck(FALSE);
+    $base_query
+      ->condition('type', $this->referencedType)
+      ->condition('title', $new_title);
+
+    $query = clone $base_query;
+    $result = $query->execute();
+    $this->assertEmpty($result, 'Referenced node does not exist yet.');
+
+    $edit = [
+      'title[0][value]' => $this->randomMachineName(),
+      'test_field[0][target_id]' => $new_title,
+    ];
+    $this->drupalGet("node/add/{$this->referencingType}");
+    $this->submitForm($edit, 'Save');
+
+    // Assert referenced node was created.
+    $query = clone $base_query;
+    $result = $query->execute();
+    $this->assertNotEmpty($result, 'Referenced node was created.');
+    $referenced_nid = key($result);
+    $referenced_node = Node::load($referenced_nid);
+
+    // Assert the referenced node is associated with referencing node.
+    $result = \Drupal::entityQuery('node')
+      ->accessCheck(FALSE)
+      ->condition('type', $this->referencingType)
+      ->execute();
+
+    $referencing_nid = key($result);
+    $referencing_node = Node::load($referencing_nid);
+    $this->assertEquals($referenced_nid, $referencing_node->test_field->target_id, 'Newly created node is referenced from the referencing node.');
+
+    // Now try to view the node and check that the referenced node is shown.
+    $this->drupalGet('node/' . $referencing_node->id());
+    $this->assertSession()->pageTextContains($referencing_node->label());
+    $this->assertSession()->pageTextContains($referenced_node->label());
+  }
+
+  /**
+   * Tests multiple target bundles.
+   *
+   * Tests if an entity reference field having multiple target bundles is
+   * storing the auto-created entity in the right destination.
+   */
+  public function testMultipleTargetBundles(): void {
+    /** @var \Drupal\taxonomy\Entity\Vocabulary[] $vocabularies */
+    $vocabularies = [];
+    for ($i = 0; $i < 2; $i++) {
+      $vid = $this->randomMachineName();
+      $vocabularies[$i] = Vocabulary::create([
+        'name' => $this->randomMachineName(),
+        'vid' => $vid,
+      ]);
+      $vocabularies[$i]->save();
+    }
+
+    // Create a taxonomy term entity reference field that saves the auto-created
+    // taxonomy terms in the second vocabulary from the two that were configured
+    // as targets.
+    $field_name = $this->randomMachineName();
+    $handler_settings = [
+      'target_bundles' => [
+        $vocabularies[0]->id() => $vocabularies[0]->id(),
+        $vocabularies[1]->id() => $vocabularies[1]->id(),
+      ],
+      'auto_create' => TRUE,
+      'auto_create_bundle' => $vocabularies[1]->id(),
+    ];
+    $this->createEntityReferenceField('node', $this->referencingType, $field_name, $this->randomString(), 'taxonomy_term', 'default', $handler_settings);
+    /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $fd */
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay('node', $this->referencingType)
+      ->setComponent($field_name, ['type' => 'entity_reference_autocomplete'])
+      ->save();
+
+    $term_name = $this->randomString();
+    $edit = [
+      $field_name . '[0][target_id]' => $term_name,
+      'title[0][value]' => $this->randomString(),
+    ];
+
+    $this->drupalGet('node/add/' . $this->referencingType);
+    $this->submitForm($edit, 'Save');
+
+    $term_storage = \Drupal::entityTypeManager()->getStorage('taxonomy_term');
+    /** @var \Drupal\taxonomy\Entity\Term $term */
+    $term = $term_storage->loadByProperties(['name' => $term_name]);
+    $term = reset($term);
+
+    // The new term is expected to be stored in the second vocabulary.
+    $this->assertEquals($vocabularies[1]->id(), $term->bundle());
+
+    /** @var \Drupal\field\Entity\FieldConfig $field_config */
+    $field_config = FieldConfig::loadByName('node', $this->referencingType, $field_name);
+    $handler_settings = $field_config->getSetting('handler_settings');
+
+    // Change the field setting to store the auto-created terms in the first
+    // vocabulary and test again.
+    $handler_settings['auto_create_bundle'] = $vocabularies[0]->id();
+    $field_config->setSetting('handler_settings', $handler_settings);
+    $field_config->save();
+
+    $term_name = $this->randomString();
+    $edit = [
+      $field_name . '[0][target_id]' => $term_name,
+      'title[0][value]' => $this->randomString(),
+    ];
+
+    $this->drupalGet('node/add/' . $this->referencingType);
+    $this->submitForm($edit, 'Save');
+    /** @var \Drupal\taxonomy\Entity\Term $term */
+    $term = $term_storage->loadByProperties(['name' => $term_name]);
+    $term = reset($term);
+
+    // The second term is expected to be stored in the first vocabulary.
+    $this->assertEquals($vocabularies[0]->id(), $term->bundle());
+
+    // @todo Re-enable this test when WebTestBase::curlHeaderCallback() provides
+    //   a way to catch and assert user-triggered errors.
+
+    // Test the case when the field config settings are inconsistent.
+    // @code
+    // unset($handler_settings['auto_create_bundle']);
+    // $field_config->setSetting('handler_settings', $handler_settings);
+    // $field_config->save();
+    //
+    // $this->drupalGet('node/add/' . $this->referencingType);
+    // $error_message = sprintf(
+    //   "Create referenced entities if they don't already exist option is enabled but a specific destination bundle is not set. You should re-visit and fix the settings of the '%s' (%s) field.",
+    //   $field_config->getLabel(),
+    //   $field_config->getName()
+    // );
+    // $this->assertErrorLogged($error_message);
+    // @endcode
+  }
+
+  /**
+   * Tests autocreation for an entity that has no bundles.
+   */
+  public function testNoBundles(): void {
+    $account = $this->drupalCreateUser([
+      'access content',
+      "create $this->referencingType content",
+      'administer entity_test content',
+    ]);
+    $this->drupalLogin($account);
+
+    $field_name = $this->randomMachineName();
+    $handler_settings = [
+      'auto_create' => TRUE,
+    ];
+    $this->createEntityReferenceField('node', $this->referencingType, $field_name, $this->randomString(), 'entity_test_no_bundle_with_label', 'default', $handler_settings);
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay('node', $this->referencingType)
+      ->setComponent($field_name, ['type' => 'entity_reference_autocomplete'])
+      ->save();
+
+    $node_title = $this->randomMachineName();
+    $name = $this->randomMachineName();
+    $edit = [
+      $field_name . '[0][target_id]' => $name,
+      'title[0][value]' => $node_title,
+    ];
+
+    $this->drupalGet('node/add/' . $this->referencingType);
+    $this->submitForm($edit, 'Save');
+
+    // Assert referenced entity was created.
+    $result = \Drupal::entityQuery('entity_test_no_bundle_with_label')
+      ->accessCheck(FALSE)
+      ->condition('name', $name)
+      ->execute();
+    $this->assertNotEmpty($result, 'Referenced entity was created.');
+    $referenced_id = key($result);
+
+    // Assert the referenced entity is associated with referencing node.
+    $result = \Drupal::entityQuery('node')
+      ->accessCheck(FALSE)
+      ->condition('type', $this->referencingType)
+      ->execute();
+    $this->assertCount(1, $result);
+    $referencing_nid = key($result);
+    $referencing_node = Node::load($referencing_nid);
+    $this->assertEquals($referenced_id, $referencing_node->$field_name->target_id, 'Newly created node is referenced from the referencing entity.');
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php

@@ -0,0 +1,181 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\Tests\SchemaCheckTestTrait;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\node\Entity\Node;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests entity reference field default values storage in CMI.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceFieldDefaultValueTest extends BrowserTestBase {
+
+  use SchemaCheckTestTrait;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  protected static $modules = ['field_ui', 'node'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * A user with permission to administer content types, node fields, etc.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create default content type.
+    $this->drupalCreateContentType(['type' => 'reference_content']);
+    $this->drupalCreateContentType(['type' => 'referenced_content']);
+
+    // Create admin user.
+    $this->adminUser = $this->drupalCreateUser([
+      'access content',
+      'administer content types',
+      'administer node fields',
+      'administer node form display',
+      'bypass node access',
+    ]);
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Tests that default values are correctly translated to UUIDs in config.
+   */
+  public function testEntityReferenceDefaultValue(): void {
+    // Create a node to be referenced.
+    $referenced_node = $this->drupalCreateNode(['type' => 'referenced_content']);
+
+    $field_name = $this->randomMachineName();
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'node',
+      'type' => 'entity_reference',
+      'settings' => ['target_type' => 'node'],
+    ]);
+    $field_storage->save();
+    $field = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'reference_content',
+      'settings' => [
+        'handler' => 'default',
+        'handler_settings' => [
+          'target_bundles' => ['referenced_content'],
+          'sort' => ['field' => '_none'],
+        ],
+      ],
+    ]);
+    $field->save();
+
+    // Set created node as default_value.
+    $field_edit = [
+      'set_default_value' => '1',
+      'default_value_input[' . $field_name . '][0][target_id]' => $referenced_node->getTitle() . ' (' . $referenced_node->id() . ')',
+    ];
+    $this->drupalGet('admin/structure/types/manage/reference_content/fields/node.reference_content.' . $field_name);
+    $this->submitForm($field_edit, 'Save settings');
+
+    // Check that default value is selected in default value form.
+    $this->drupalGet('admin/structure/types/manage/reference_content/fields/node.reference_content.' . $field_name);
+    $this->assertSession()->responseContains('name="default_value_input[' . $field_name . '][0][target_id]" value="' . $referenced_node->getTitle() . ' (' . $referenced_node->id() . ')');
+
+    // Check if the ID has been converted to UUID in config entity.
+    $config_entity = $this->config('field.field.node.reference_content.' . $field_name)->get();
+    $this->assertTrue(isset($config_entity['default_value'][0]['target_uuid']), 'Default value contains target_uuid property');
+    $this->assertEquals($referenced_node->uuid(), $config_entity['default_value'][0]['target_uuid'], 'Content uuid and config entity uuid are the same');
+    // Ensure the configuration has the expected dependency on the entity that
+    // is being used a default value.
+    $this->assertEquals([$referenced_node->getConfigDependencyName()], $config_entity['dependencies']['content']);
+
+    // Clear field definitions cache in order to avoid stale cache values.
+    \Drupal::service('entity_field.manager')->clearCachedFieldDefinitions();
+
+    // Create a new node to check that UUID has been converted to numeric ID.
+    $new_node = Node::create(['type' => 'reference_content']);
+    $this->assertEquals($new_node->get($field_name)->offsetGet(0)->target_id, $referenced_node->id());
+
+    // Ensure that the entity reference config schemas are correct.
+    $field_config = $this->config('field.field.node.reference_content.' . $field_name);
+    $this->assertConfigSchema(\Drupal::service('config.typed'), $field_config->getName(), $field_config->get());
+    $field_storage_config = $this->config('field.storage.node.' . $field_name);
+    $this->assertConfigSchema(\Drupal::service('config.typed'), $field_storage_config->getName(), $field_storage_config->get());
+  }
+
+  /**
+   * Tests that dependencies due to default values can be removed.
+   *
+   * @see \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::onDependencyRemoval()
+   */
+  public function testEntityReferenceDefaultConfigValue(): void {
+    // Create a node to be referenced.
+    $referenced_node_type = $this->drupalCreateContentType(['type' => 'referenced_config_to_delete']);
+    $referenced_node_type2 = $this->drupalCreateContentType(['type' => 'referenced_config_to_preserve']);
+
+    $field_name = $this->randomMachineName();
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'node',
+      'type' => 'entity_reference',
+      'settings' => ['target_type' => 'node_type'],
+      'cardinality' => FieldStorageConfig::CARDINALITY_UNLIMITED,
+    ]);
+    $field_storage->save();
+    $field = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'reference_content',
+      'settings' => [
+        'handler' => 'default',
+        'handler_settings' => [
+          'sort' => ['field' => '_none'],
+        ],
+      ],
+    ]);
+    $field->save();
+
+    // Set created node as default_value.
+    $field_edit = [
+      'set_default_value' => '1',
+      'default_value_input[' . $field_name . '][0][target_id]' => $referenced_node_type->label() . ' (' . $referenced_node_type->id() . ')',
+      'default_value_input[' . $field_name . '][1][target_id]' => $referenced_node_type2->label() . ' (' . $referenced_node_type2->id() . ')',
+    ];
+    $this->drupalGet('admin/structure/types/manage/reference_content/fields/node.reference_content.' . $field_name);
+    $this->assertSession()->fieldExists("default_value_input[{$field_name}][0][target_id]");
+    $this->assertSession()->fieldNotExists("default_value_input[{$field_name}][1][target_id]");
+    $this->submitForm([], 'Add another item');
+    $this->assertSession()->fieldExists("default_value_input[{$field_name}][1][target_id]");
+    $this->submitForm($field_edit, 'Save settings');
+
+    // Check that the field has a dependency on the default value.
+    $config_entity = $this->config('field.field.node.reference_content.' . $field_name)->get();
+    $this->assertContains($referenced_node_type->getConfigDependencyName(), $config_entity['dependencies']['config'], 'The node type referenced_config_to_delete is a dependency of the field.');
+    $this->assertContains($referenced_node_type2->getConfigDependencyName(), $config_entity['dependencies']['config'], 'The node type referenced_config_to_preserve is a dependency of the field.');
+
+    // Check that the field does not have a dependency on the default value
+    // after deleting the node type.
+    $referenced_node_type->delete();
+    $config_entity = $this->config('field.field.node.reference_content.' . $field_name)->get();
+    $this->assertNotContains($referenced_node_type->getConfigDependencyName(), $config_entity['dependencies']['config'], 'The node type referenced_config_to_delete not a dependency of the field.');
+    $this->assertContains($referenced_node_type2->getConfigDependencyName(), $config_entity['dependencies']['config'], 'The node type referenced_config_to_preserve is a dependency of the field.');
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldTranslatedReferenceViewTest.php

@@ -0,0 +1,366 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\content_translation\Traits\ContentTranslationTestTrait;
+
+/**
+ * Tests the translation of entity reference field display on nodes.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceFieldTranslatedReferenceViewTest extends BrowserTestBase {
+
+  use ContentTranslationTestTrait;
+
+  /**
+   * Flag indicating whether the field is translatable.
+   *
+   * @var bool
+   */
+  protected $translatable = TRUE;
+
+  /**
+   * The langcode of the source language.
+   *
+   * @var string
+   */
+  protected $baseLangcode = 'en';
+
+  /**
+   * Target langcode for translation.
+   *
+   * @var string
+   */
+  protected $translateToLangcode = 'hu';
+
+  /**
+   * The test entity type name.
+   *
+   * @var string
+   */
+  protected $testEntityTypeName = 'node';
+
+  /**
+   * Entity type which have the entity reference field.
+   *
+   * @var \Drupal\node\Entity\NodeType
+   */
+  protected $referrerType;
+
+  /**
+   * Entity type which can be referenced.
+   *
+   * @var \Drupal\node\Entity\NodeType
+   */
+  protected $referencedType;
+
+  /**
+   * The referrer entity.
+   *
+   * @var \Drupal\node\Entity\Node
+   */
+  protected $referrerEntity;
+
+  /**
+   * The entity to refer.
+   *
+   * @var \Drupal\node\Entity\Node
+   */
+  protected $referencedEntityWithoutTranslation;
+
+  /**
+   * The entity to refer.
+   *
+   * @var \Drupal\node\Entity\Node
+   */
+  protected $referencedEntityWithTranslation;
+
+  /**
+   * The machine name of the entity reference field.
+   *
+   * @var string
+   */
+  protected $referenceFieldName = 'test_reference_field';
+
+  /**
+   * The label of the untranslated referenced entity, used in assertions.
+   *
+   * @var string
+   */
+  protected $labelOfNotTranslatedReference;
+
+  /**
+   * The original label of the referenced entity, used in assertions.
+   *
+   * @var string
+   */
+  protected $originalLabel;
+
+  /**
+   * The translated label of the referenced entity, used in assertions.
+   *
+   * @var string
+   */
+  protected $translatedLabel;
+
+  /**
+   * A user with permission to edit the referrer entity.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $webUser;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'language',
+    'content_translation',
+    'node',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->labelOfNotTranslatedReference = $this->randomMachineName();
+    $this->originalLabel = $this->randomMachineName();
+    $this->translatedLabel = $this->randomMachineName();
+
+    $this->setUpLanguages();
+
+    // We setup languages, so we need to ensure that the language manager
+    // and language path processor is updated.
+    $this->rebuildContainer();
+
+    $this->setUpContentTypes();
+    $this->enableTranslation();
+    $this->setUpEntityReferenceField();
+    $this->createContent();
+
+    $this->webUser = $this->drupalCreateUser([
+      'edit any ' . $this->referrerType->id() . ' content',
+    ]);
+  }
+
+  /**
+   * Tests if the entity is displayed in an entity reference field.
+   */
+  public function testEntityReferenceDisplay(): void {
+    // Create a translated referrer entity.
+    $this->referrerEntity = $this->createReferrerEntity();
+    $this->assertEntityReferenceDisplay();
+    $this->assertEntityReferenceFormDisplay();
+
+    // Disable translation for referrer content type.
+    static::disableBundleTranslation('node', 'referrer');
+
+    // Create a referrer entity without translation.
+    $this->referrerEntity = $this->createReferrerEntity(FALSE);
+    $this->assertEntityReferenceDisplay();
+    $this->assertEntityReferenceFormDisplay();
+  }
+
+  /**
+   * Assert entity reference display.
+   *
+   * @internal
+   */
+  protected function assertEntityReferenceDisplay(): void {
+    $url = $this->referrerEntity->toUrl();
+    $translation_url = $this->referrerEntity->toUrl('canonical', ['language' => ConfigurableLanguage::load($this->translateToLangcode)]);
+
+    $this->drupalGet($url);
+    $this->assertSession()->pageTextContains($this->labelOfNotTranslatedReference);
+    $this->assertSession()->pageTextContains($this->originalLabel);
+    $this->assertSession()->pageTextNotContains($this->translatedLabel);
+    $this->drupalGet($translation_url);
+    $this->assertSession()->pageTextContains($this->labelOfNotTranslatedReference);
+    $this->assertSession()->pageTextNotContains($this->originalLabel);
+    $this->assertSession()->pageTextContains($this->translatedLabel);
+  }
+
+  /**
+   * Assert entity reference form display.
+   *
+   * @internal
+   */
+  protected function assertEntityReferenceFormDisplay(): void {
+    $this->drupalLogin($this->webUser);
+    $url = $this->referrerEntity->toUrl('edit-form');
+    $translation_url = $this->referrerEntity->toUrl('edit-form', ['language' => ConfigurableLanguage::load($this->translateToLangcode)]);
+
+    $this->drupalGet($url);
+    $this->assertSession()->fieldValueEquals('test_reference_field[0][target_id]', $this->originalLabel . ' (1)');
+    $this->assertSession()->fieldValueEquals('test_reference_field[1][target_id]', $this->labelOfNotTranslatedReference . ' (2)');
+    $this->drupalGet($translation_url);
+    $this->assertSession()->fieldValueEquals('test_reference_field[0][target_id]', $this->translatedLabel . ' (1)');
+    $this->assertSession()->fieldValueEquals('test_reference_field[1][target_id]', $this->labelOfNotTranslatedReference . ' (2)');
+    $this->drupalLogout();
+  }
+
+  /**
+   * Adds additional languages.
+   */
+  protected function setUpLanguages() {
+    static::createLanguageFromLangcode($this->translateToLangcode);
+  }
+
+  /**
+   * Creates a test subject contents, with translation.
+   */
+  protected function createContent() {
+    $this->referencedEntityWithTranslation = $this->createReferencedEntityWithTranslation();
+    $this->referencedEntityWithoutTranslation = $this->createNotTranslatedReferencedEntity();
+  }
+
+  /**
+   * Enables translations where it needed.
+   */
+  protected function enableTranslation() {
+    // Enable translation for the entity types.
+    $this->enableContentTranslation($this->testEntityTypeName, $this->referrerType->id());
+    $this->enableContentTranslation($this->testEntityTypeName, $this->referencedType->id());
+  }
+
+  /**
+   * Adds term reference field for the article content type.
+   */
+  protected function setUpEntityReferenceField() {
+    FieldStorageConfig::create([
+      'field_name' => $this->referenceFieldName,
+      'entity_type' => $this->testEntityTypeName,
+      'type' => 'entity_reference',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+      'translatable' => $this->translatable,
+      'settings' => [
+        'allowed_values' => [
+          [
+            'target_type' => $this->testEntityTypeName,
+          ],
+        ],
+      ],
+    ])->save();
+
+    FieldConfig::create([
+      'field_name' => $this->referenceFieldName,
+      'bundle' => $this->referrerType->id(),
+      'entity_type' => $this->testEntityTypeName,
+    ])
+      ->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getFormDisplay($this->testEntityTypeName, $this->referrerType->id())
+      ->setComponent($this->referenceFieldName, [
+        'type' => 'entity_reference_autocomplete',
+      ])
+      ->save();
+    $display_repository->getViewDisplay($this->testEntityTypeName, $this->referrerType->id())
+      ->setComponent($this->referenceFieldName, [
+        'type' => 'entity_reference_label',
+      ])
+      ->save();
+  }
+
+  /**
+   * Create content types.
+   */
+  protected function setUpContentTypes() {
+    $this->referrerType = $this->drupalCreateContentType([
+      'type' => 'referrer',
+      'name' => 'Referrer',
+    ]);
+    $this->referencedType = $this->drupalCreateContentType([
+      'type' => 'referenced_page',
+      'name' => 'Referenced Page',
+    ]);
+  }
+
+  /**
+   * Create a referenced entity with a translation.
+   */
+  protected function createReferencedEntityWithTranslation() {
+    /** @var \Drupal\node\Entity\Node $node */
+    $node = \Drupal::entityTypeManager()->getStorage($this->testEntityTypeName)->create([
+      'title' => $this->originalLabel,
+      'type' => $this->referencedType->id(),
+      'description' => [
+        'value' => $this->randomMachineName(),
+        'format' => 'basic_html',
+      ],
+      'langcode' => $this->baseLangcode,
+    ]);
+    $node->save();
+    $node->addTranslation($this->translateToLangcode, [
+      'title' => $this->translatedLabel,
+    ]);
+    $node->save();
+
+    return $node;
+  }
+
+  /**
+   * Create the referenced entity.
+   */
+  protected function createNotTranslatedReferencedEntity() {
+    /** @var \Drupal\node\Entity\Node $node */
+    $node = \Drupal::entityTypeManager()->getStorage($this->testEntityTypeName)->create([
+      'title' => $this->labelOfNotTranslatedReference,
+      'type' => $this->referencedType->id(),
+      'description' => [
+        'value' => $this->randomMachineName(),
+        'format' => 'basic_html',
+      ],
+      'langcode' => $this->baseLangcode,
+    ]);
+    $node->save();
+
+    return $node;
+  }
+
+  /**
+   * Create the referrer entity.
+   */
+  protected function createReferrerEntity($translatable = TRUE) {
+    /** @var \Drupal\node\Entity\Node $node */
+    $node = \Drupal::entityTypeManager()->getStorage($this->testEntityTypeName)->create([
+      'title' => $this->randomMachineName(),
+      'type' => $this->referrerType->id(),
+      'description' => [
+        'value' => $this->randomMachineName(),
+        'format' => 'basic_html',
+      ],
+      $this->referenceFieldName => [
+        ['target_id' => $this->referencedEntityWithTranslation->id()],
+        ['target_id' => $this->referencedEntityWithoutTranslation->id()],
+      ],
+      'langcode' => $this->baseLangcode,
+    ]);
+    if ($translatable) {
+      $node->addTranslation($this->translateToLangcode, $node->toArray());
+    }
+    $node->save();
+
+    return $node;
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFileUploadTest.php

@@ -0,0 +1,148 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\TestFileCreationTrait;
+
+/**
+ * Tests an autocomplete widget with file upload.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceFileUploadTest extends BrowserTestBase {
+
+  use TestFileCreationTrait;
+
+  protected static $modules = ['node', 'file'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of a content type that will reference $referencedType.
+   *
+   * @var string
+   */
+  protected $referencingType;
+
+  /**
+   * The name of a content type that will be referenced by $referencingType.
+   *
+   * @var string
+   */
+  protected $referencedType;
+
+  /**
+   * Node id.
+   *
+   * @var int
+   */
+  protected $nodeId;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create "referencing" and "referenced" node types.
+    $referencing = $this->drupalCreateContentType();
+    $this->referencingType = $referencing->id();
+
+    $referenced = $this->drupalCreateContentType();
+    $this->referencedType = $referenced->id();
+    $this->nodeId = $this->drupalCreateNode(['type' => $referenced->id()])->id();
+
+    FieldStorageConfig::create([
+      'field_name' => 'test_field',
+      'entity_type' => 'node',
+      'translatable' => FALSE,
+      'entity_types' => [],
+      'settings' => [
+        'target_type' => 'node',
+      ],
+      'type' => 'entity_reference',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ])->save();
+
+    FieldConfig::create([
+      'label' => 'Entity reference field',
+      'field_name' => 'test_field',
+      'entity_type' => 'node',
+      'required' => TRUE,
+      'bundle' => $referencing->id(),
+      'settings' => [
+        'handler' => 'default',
+        'handler_settings' => [
+          // Reference a single vocabulary.
+          'target_bundles' => [
+            $referenced->id(),
+          ],
+        ],
+      ],
+    ])->save();
+
+    // Create a file field.
+    $file_field_name = 'file_field';
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $file_field_name,
+      'entity_type' => 'node',
+      'type' => 'file',
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'entity_type' => 'node',
+      'field_storage' => $field_storage,
+      'bundle' => $referencing->id(),
+      'label' => $this->randomMachineName() . '_label',
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getViewDisplay('node', $referencing->id())
+      ->setComponent('test_field')
+      ->setComponent($file_field_name)
+      ->save();
+    $display_repository->getFormDisplay('node', $referencing->id())
+      ->setComponent('test_field', [
+        'type' => 'entity_reference_autocomplete',
+      ])
+      ->setComponent($file_field_name, [
+        'type' => 'file_generic',
+      ])
+      ->save();
+  }
+
+  /**
+   * Tests that the autocomplete input element does not cause ajax fatal.
+   */
+  public function testFileUpload(): void {
+    $user1 = $this->drupalCreateUser([
+      'access content',
+      "create $this->referencingType content",
+    ]);
+    $this->drupalLogin($user1);
+
+    $test_file = current($this->getTestFiles('text'));
+    $edit['files[file_field_0]'] = \Drupal::service('file_system')->realpath($test_file->uri);
+    $this->drupalGet('node/add/' . $this->referencingType);
+    $this->submitForm($edit, 'Upload');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [
+      'title[0][value]' => $this->randomMachineName(),
+      'test_field[0][target_id]' => $this->nodeId,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->statusCodeEquals(200);
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php

@@ -0,0 +1,249 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\config\Traits\AssertConfigEntityImportTrait;
+use Drupal\Tests\field\Traits\EntityReferenceFieldCreationTrait;
+
+/**
+ * Tests various Entity reference UI components.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceIntegrationTest extends BrowserTestBase {
+
+  use AssertConfigEntityImportTrait;
+  use EntityReferenceFieldCreationTrait;
+
+  /**
+   * The entity type used in this test.
+   *
+   * @var string
+   */
+  protected $entityType = 'entity_test';
+
+  /**
+   * The bundle used in this test.
+   *
+   * @var string
+   */
+  protected $bundle = 'entity_test';
+
+  /**
+   * The name of the field used in this test.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  protected static $modules = ['config_test', 'entity_test', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a test user.
+    $web_user = $this->drupalCreateUser([
+      'administer entity_test content',
+      'administer entity_test fields',
+      'view test entity',
+    ]);
+    $this->drupalLogin($web_user);
+  }
+
+  /**
+   * Tests the entity reference field with all its supported field widgets.
+   */
+  public function testSupportedEntityTypesAndWidgets(): void {
+    foreach ($this->getTestEntities() as $key => $referenced_entities) {
+      $this->fieldName = 'field_test_' . $referenced_entities[0]->getEntityTypeId();
+
+      // Create an Entity reference field.
+      $this->createEntityReferenceField($this->entityType, $this->bundle, $this->fieldName, $this->fieldName, $referenced_entities[0]->getEntityTypeId(), 'default', [], 2);
+
+      /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+      $display_repository = \Drupal::service('entity_display.repository');
+
+      // Test the default 'entity_reference_autocomplete' widget.
+      $display_repository->getFormDisplay($this->entityType, $this->bundle)
+        ->setComponent($this->fieldName)
+        ->save();
+
+      $entity_name = $this->randomMachineName();
+      $edit = [
+        'name[0][value]' => $entity_name,
+        $this->fieldName . '[0][target_id]' => $referenced_entities[0]->label() . ' (' . $referenced_entities[0]->id() . ')',
+        // Test an input of the entity label without an ' (entity_id)' suffix.
+        $this->fieldName . '[1][target_id]' => $referenced_entities[1]->label(),
+      ];
+      $this->drupalGet($this->entityType . '/add');
+      $this->submitForm($edit, 'Save');
+      $this->assertFieldValues($entity_name, $referenced_entities);
+
+      // Try to post the form again with no modification and check if the field
+      // values remain the same.
+      /** @var \Drupal\Core\Entity\EntityStorageInterface $storage */
+      $storage = $this->container->get('entity_type.manager')->getStorage($this->entityType);
+      $entity = current($storage->loadByProperties(['name' => $entity_name]));
+      $this->drupalGet($this->entityType . '/manage/' . $entity->id() . '/edit');
+      $this->assertSession()->fieldValueEquals($this->fieldName . '[0][target_id]', $referenced_entities[0]->label() . ' (' . $referenced_entities[0]->id() . ')');
+      $this->assertSession()->fieldValueEquals($this->fieldName . '[1][target_id]', $referenced_entities[1]->label() . ' (' . $referenced_entities[1]->id() . ')');
+
+      $this->submitForm([], 'Save');
+      $this->assertFieldValues($entity_name, $referenced_entities);
+
+      // Test the 'entity_reference_autocomplete_tags' widget.
+      $display_repository->getFormDisplay($this->entityType, $this->bundle)
+        ->setComponent($this->fieldName, [
+          'type' => 'entity_reference_autocomplete_tags',
+        ])->save();
+
+      $entity_name = $this->randomMachineName();
+      $target_id = $referenced_entities[0]->label() . ' (' . $referenced_entities[0]->id() . ')';
+      // Test an input of the entity label without an ' (entity_id)' suffix.
+      $target_id .= ', ' . $referenced_entities[1]->label();
+      $edit = [
+        'name[0][value]' => $entity_name,
+        $this->fieldName . '[target_id]' => $target_id,
+      ];
+      $this->drupalGet($this->entityType . '/add');
+      $this->submitForm($edit, 'Save');
+      $this->assertFieldValues($entity_name, $referenced_entities);
+
+      // Try to post the form again with no modification and check if the field
+      // values remain the same.
+      $entity = current($storage->loadByProperties(['name' => $entity_name]));
+      $this->drupalGet($this->entityType . '/manage/' . $entity->id() . '/edit');
+      $this->assertSession()->fieldValueEquals($this->fieldName . '[target_id]', $target_id . ' (' . $referenced_entities[1]->id() . ')');
+
+      $this->submitForm([], 'Save');
+      $this->assertFieldValues($entity_name, $referenced_entities);
+
+      // Test all the other widgets supported by the entity reference field.
+      // Since we don't know the form structure for these widgets, just test
+      // that editing and saving an already created entity works.
+      $exclude = ['entity_reference_autocomplete', 'entity_reference_autocomplete_tags'];
+      $entity = current($storage->loadByProperties(['name' => $entity_name]));
+      $supported_widgets = \Drupal::service('plugin.manager.field.widget')->getOptions('entity_reference');
+      $supported_widget_types = array_diff(array_keys($supported_widgets), $exclude);
+
+      foreach ($supported_widget_types as $widget_type) {
+        $display_repository->getFormDisplay($this->entityType, $this->bundle)
+          ->setComponent($this->fieldName, [
+            'type' => $widget_type,
+          ])->save();
+
+        $this->drupalGet($this->entityType . '/manage/' . $entity->id() . '/edit');
+        $this->submitForm([], 'Save');
+        $this->assertFieldValues($entity_name, $referenced_entities);
+      }
+
+      // Reset to the default 'entity_reference_autocomplete' widget.
+      $display_repository->getFormDisplay($this->entityType, $this->bundle)
+        ->setComponent($this->fieldName)
+        ->save();
+
+      // Set first entity as the default_value.
+      $field_edit = [
+        'set_default_value' => '1',
+        'default_value_input[' . $this->fieldName . '][0][target_id]' => $referenced_entities[0]->label() . ' (' . $referenced_entities[0]->id() . ')',
+      ];
+      if ($key == 'content') {
+        $field_edit['settings[handler_settings][target_bundles][' . $referenced_entities[0]->getEntityTypeId() . ']'] = TRUE;
+      }
+      $this->drupalGet($this->entityType . '/structure/' . $this->bundle . '/fields/' . $this->entityType . '.' . $this->bundle . '.' . $this->fieldName);
+      $this->submitForm($field_edit, 'Save settings');
+      // Ensure the configuration has the expected dependency on the entity that
+      // is being used a default value.
+      $field = FieldConfig::loadByName($this->entityType, $this->bundle, $this->fieldName);
+      $this->assertContains($referenced_entities[0]->getConfigDependencyName(), $field->getDependencies()[$key], 'Expected ' . $key . ' dependency ' . $referenced_entities[0]->getConfigDependencyName() . ' found');
+      // Ensure that the field can be imported without change even after the
+      // default value deleted.
+      $referenced_entities[0]->delete();
+      // Reload the field since deleting the default value can change the field.
+      \Drupal::entityTypeManager()->getStorage($field->getEntityTypeId())->resetCache([$field->id()]);
+      $field = FieldConfig::loadByName($this->entityType, $this->bundle, $this->fieldName);
+      $this->assertConfigEntityImport($field);
+
+      // Once the default value has been removed after saving the dependency
+      // should be removed.
+      $field = FieldConfig::loadByName($this->entityType, $this->bundle, $this->fieldName);
+      $field->save();
+      $dependencies = $field->getDependencies();
+      $this->assertFalse(isset($dependencies[$key]) && in_array($referenced_entities[0]->getConfigDependencyName(), $dependencies[$key]), $key . ' dependency ' . $referenced_entities[0]->getConfigDependencyName() . ' does not exist.');
+    }
+  }
+
+  /**
+   * Asserts that the reference field values are correct.
+   *
+   * @param string $entity_name
+   *   The name of the test entity.
+   * @param \Drupal\Core\Entity\EntityInterface[] $referenced_entities
+   *   An array of referenced entities.
+   *
+   * @internal
+   */
+  protected function assertFieldValues(string $entity_name, array $referenced_entities): void {
+    $entity = current($this->container->get('entity_type.manager')->getStorage(
+    $this->entityType)->loadByProperties(['name' => $entity_name]));
+
+    $this->assertNotEmpty($entity, "$this->entityType: Entity found in the database.");
+
+    $this->assertEquals($referenced_entities[0]->id(), $entity->{$this->fieldName}->target_id);
+    $this->assertEquals($referenced_entities[0]->id(), $entity->{$this->fieldName}->entity->id());
+    $this->assertEquals($referenced_entities[0]->label(), $entity->{$this->fieldName}->entity->label());
+
+    $this->assertEquals($referenced_entities[1]->id(), $entity->{$this->fieldName}[1]->target_id);
+    $this->assertEquals($referenced_entities[1]->id(), $entity->{$this->fieldName}[1]->entity->id());
+    $this->assertEquals($referenced_entities[1]->label(), $entity->{$this->fieldName}[1]->entity->label());
+  }
+
+  /**
+   * Creates two content and two config test entities.
+   *
+   * @return array
+   *   An array of entity objects.
+   */
+  protected function getTestEntities() {
+    $storage = \Drupal::entityTypeManager()->getStorage('config_test');
+    $config_entity_1 = $storage->create(['id' => $this->randomMachineName(), 'label' => $this->randomMachineName()]);
+    $config_entity_1->save();
+    $config_entity_2 = $storage->create(['id' => $this->randomMachineName(), 'label' => $this->randomMachineName()]);
+    $config_entity_2->save();
+
+    $content_entity_1 = EntityTest::create(['name' => $this->randomMachineName()]);
+    $content_entity_1->save();
+    $content_entity_2 = EntityTest::create(['name' => $this->randomMachineName()]);
+    $content_entity_2->save();
+
+    return [
+      'config' => [
+        $config_entity_1,
+        $config_entity_2,
+      ],
+      'content' => [
+        $content_entity_1,
+        $content_entity_2,
+      ],
+    ];
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/EntityReferenceXSSTest.php

@@ -0,0 +1,93 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\field\Traits\EntityReferenceFieldCreationTrait;
+
+/**
+ * Tests possible XSS security issues in entity references.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceXSSTest extends BrowserTestBase {
+
+  use EntityReferenceFieldCreationTrait;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node'];
+
+  /**
+   * {@inheritdoc}
+   *
+   * @todo Remove and fix test to not rely on super user.
+   * @see https://www.drupal.org/project/drupal/issues/3437620
+   */
+  protected bool $usesSuperUserAccessPolicy = TRUE;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Tests markup is escaped in the entity reference select and label formatter.
+   */
+  public function testEntityReferenceXSS(): void {
+    $this->drupalCreateContentType(['type' => 'article']);
+
+    // Create a node with markup in the title.
+    $node_type_one = $this->drupalCreateContentType();
+    $node = [
+      'type' => $node_type_one->id(),
+      'title' => '<em>I am kitten</em>',
+    ];
+    $referenced_node = $this->drupalCreateNode($node);
+
+    $node_type_two = $this->drupalCreateContentType(['name' => '<em>bundle with markup</em>']);
+    $this->drupalCreateNode([
+      'type' => $node_type_two->id(),
+      'title' => 'My bundle has markup',
+    ]);
+
+    $this->createEntityReferenceField('node', 'article', 'entity_reference_test', 'Entity Reference test', 'node', 'default', ['target_bundles' => [$node_type_one->id(), $node_type_two->id()]]);
+
+    EntityFormDisplay::load('node.article.default')
+      ->setComponent('entity_reference_test', ['type' => 'options_select'])
+      ->save();
+    EntityViewDisplay::load('node.article.default')
+      ->setComponent('entity_reference_test', ['type' => 'entity_reference_label'])
+      ->save();
+
+    // Create a node and reference the node with markup in the title.
+    $this->drupalLogin($this->rootUser);
+    $this->drupalGet('node/add/article');
+    $this->assertSession()->assertEscaped($referenced_node->getTitle());
+    $this->assertSession()->assertEscaped($node_type_two->label());
+
+    $edit = [
+      'title[0][value]' => $this->randomString(),
+      'entity_reference_test' => $referenced_node->id(),
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->assertEscaped($referenced_node->getTitle());
+
+    // Test the options_buttons type.
+    EntityFormDisplay::load('node.article.default')
+      ->setComponent('entity_reference_test', ['type' => 'options_buttons'])
+      ->save();
+    $this->drupalGet('node/add/article');
+    $this->assertSession()->assertEscaped($referenced_node->getTitle());
+    // options_buttons does not support optgroups.
+    $this->assertSession()->pageTextNotContains('bundle with markup');
+  }
+
+}

core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php

@@ -0,0 +1,130 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\EntityReference\Views;
+
+use Drupal\Component\Serialization\Json;
+use Drupal\Component\Utility\Crypt;
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Site\Settings;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\field\Traits\EntityReferenceFieldCreationTrait;
+use Drupal\views\Views;
+
+/**
+ * Tests entity reference selection handler.
+ *
+ * @group entity_reference
+ */
+class SelectionTest extends BrowserTestBase {
+
+  use EntityReferenceFieldCreationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'node',
+    'views',
+    'entity_reference_test',
+    'entity_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * An array of node titles, keyed by content type and node ID.
+   *
+   * @var \Drupal\node\NodeInterface[]
+   */
+  protected $nodes = [];
+
+  /**
+   * The handler settings for the entity reference field.
+   *
+   * @var array
+   */
+  protected $handlerSettings;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create content types and nodes.
+    $type1 = $this->drupalCreateContentType()->id();
+    $type2 = $this->drupalCreateContentType()->id();
+    // Add some characters that should be escaped but not double escaped.
+    $node1 = $this->drupalCreateNode(['type' => $type1, 'title' => 'Test first node &<>']);
+    $node2 = $this->drupalCreateNode(['type' => $type1, 'title' => 'Test second node &&&']);
+    $node3 = $this->drupalCreateNode(['type' => $type2, 'title' => 'Test third node <span />']);
+
+    foreach ([$node1, $node2, $node3] as $node) {
+      $this->nodes[$node->id()] = $node;
+    }
+
+    // Ensure the bundle to which the field is attached actually exists, or we
+    // will get config validation errors.
+    entity_test_create_bundle('test_bundle');
+
+    // Create an entity reference field.
+    $handler_settings = [
+      'view' => [
+        'view_name' => 'test_entity_reference',
+        'display_name' => 'entity_reference_1',
+      ],
+    ];
+    $this->handlerSettings = $handler_settings;
+    $this->createEntityReferenceField('entity_test', 'test_bundle', 'test_field', $this->randomString(), 'node', 'views', $handler_settings);
+  }
+
+  /**
+   * Tests that the Views selection handles the views output properly.
+   */
+  public function testAutocompleteOutput(): void {
+    // Reset any internal static caching.
+    \Drupal::service('entity_type.manager')->getStorage('node')->resetCache();
+
+    $view = Views::getView('test_entity_reference');
+    $view->setDisplay();
+
+    // Enable the display of the 'type' field so we can test that the output
+    // does not contain only the entity label.
+    $fields = $view->displayHandlers->get('entity_reference_1')->getOption('fields');
+    $fields['type']['exclude'] = FALSE;
+    $view->displayHandlers->get('entity_reference_1')->setOption('fields', $fields);
+    $view->save();
+
+    // Prepare the selection settings key needed by the entity reference
+    // autocomplete route.
+    $target_type = 'node';
+    $selection_handler = 'views';
+    $selection_settings = $this->handlerSettings;
+    $selection_settings_key = Crypt::hmacBase64(serialize($selection_settings) . $target_type . $selection_handler, Settings::getHashSalt());
+    \Drupal::keyValue('entity_autocomplete')->set($selection_settings_key, $selection_settings);
+
+    $result = Json::decode($this->drupalGet('entity_reference_autocomplete/' . $target_type . '/' . $selection_handler . '/' . $selection_settings_key, ['query' => ['q' => 't']]));
+
+    $expected = [
+      0 => [
+        'value' => $this->nodes[1]->bundle() . ': ' . $this->nodes[1]->label() . ' (' . $this->nodes[1]->id() . ')',
+        'label' => '<span class="views-field views-field-type"><span class="field-content">' . $this->nodes[1]->bundle() . '</span></span>: <span class="views-field views-field-title"><span class="field-content">' . Html::escape($this->nodes[1]->label()) . '</span></span>',
+      ],
+      1 => [
+        'value' => $this->nodes[2]->bundle() . ': ' . $this->nodes[2]->label() . ' (' . $this->nodes[2]->id() . ')',
+        'label' => '<span class="views-field views-field-type"><span class="field-content">' . $this->nodes[2]->bundle() . '</span></span>: <span class="views-field views-field-title"><span class="field-content">' . Html::escape($this->nodes[2]->label()) . '</span></span>',
+      ],
+      2 => [
+        'value' => $this->nodes[3]->bundle() . ': ' . $this->nodes[3]->label() . ' (' . $this->nodes[3]->id() . ')',
+        'label' => '<span class="views-field views-field-type"><span class="field-content">' . $this->nodes[3]->bundle() . '</span></span>: <span class="views-field views-field-title"><span class="field-content">' . Html::escape($this->nodes[3]->label()) . '</span></span>',
+      ],
+    ];
+    $this->assertEquals($expected, $result, 'The autocomplete result of the Views entity reference selection handler contains the proper output.');
+  }
+
+}

core/modules/field/tests/src/Functional/FieldAccessTest.php

@@ -0,0 +1,103 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests Field access.
+ *
+ * @group field
+ */
+class FieldAccessTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node', 'field_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Node entity to use in this test.
+   *
+   * @var \Drupal\node\Entity\Node
+   */
+  protected $node;
+
+  /**
+   * Field value to test display on nodes.
+   *
+   * @var string
+   */
+  protected $testViewFieldValue;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $web_user = $this->drupalCreateUser(['view test_view_field content']);
+    $this->drupalLogin($web_user);
+
+    // Create content type.
+    $content_type_info = $this->drupalCreateContentType();
+    $content_type = $content_type_info->id();
+
+    $field_storage = [
+      'field_name' => 'test_view_field',
+      'entity_type' => 'node',
+      'type' => 'text',
+    ];
+    FieldStorageConfig::create($field_storage)->save();
+    $field = [
+      'field_name' => $field_storage['field_name'],
+      'entity_type' => 'node',
+      'bundle' => $content_type,
+    ];
+    FieldConfig::create($field)->save();
+
+    // Assign display properties for the 'default' and 'teaser' view modes.
+    foreach (['default', 'teaser'] as $view_mode) {
+      \Drupal::service('entity_display.repository')
+        ->getViewDisplay('node', $content_type, $view_mode)
+        ->setComponent($field_storage['field_name'])
+        ->save();
+    }
+
+    // Create test node.
+    $this->testViewFieldValue = 'This is some text';
+    $settings = [];
+    $settings['type'] = $content_type;
+    $settings['title'] = 'Field view access test';
+    $settings['test_view_field'] = [['value' => $this->testViewFieldValue]];
+    $this->node = $this->drupalCreateNode($settings);
+  }
+
+  /**
+   * Tests that hook_entity_field_access() is called.
+   */
+  public function testFieldAccess(): void {
+
+    // Assert the text is visible.
+    $this->drupalGet('node/' . $this->node->id());
+    $this->assertSession()->pageTextContains($this->testViewFieldValue);
+
+    // Assert the text is not visible for anonymous users.
+    // The field_test module implements hook_entity_field_access() which will
+    // specifically target the 'test_view_field' field.
+    $this->drupalLogout();
+    $this->drupalGet('node/' . $this->node->id());
+    $this->assertSession()->pageTextNotContains($this->testViewFieldValue);
+  }
+
+}

core/modules/field/tests/src/Functional/FieldDefaultValueCallbackTest.php

@@ -0,0 +1,104 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the default value callback.
+ *
+ * @group field
+ */
+class FieldDefaultValueCallbackTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node', 'field_test', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   *
+   * @todo Remove and fix test to not rely on super user.
+   * @see https://www.drupal.org/project/drupal/issues/3437620
+   */
+  protected bool $usesSuperUserAccessPolicy = TRUE;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The field name.
+   *
+   * @var string
+   */
+  private $fieldName;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->fieldName = 'field_test';
+
+    // Create Article node types.
+    if ($this->profile != 'standard') {
+      $this->drupalCreateContentType([
+        'type' => 'article',
+        'name' => 'Article',
+      ]);
+    }
+
+  }
+
+  public function testDefaultValueCallbackForm(): void {
+    // Create a field and storage for checking.
+    /** @var \Drupal\field\Entity\FieldStorageConfig $field_storage */
+    FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => 'node',
+      'type' => 'text',
+    ])->save();
+    /** @var \Drupal\field\Entity\FieldConfig $field_config */
+    $field_config = FieldConfig::create([
+      'entity_type' => 'node',
+      'field_name' => $this->fieldName,
+      'bundle' => 'article',
+    ]);
+    $field_config->save();
+
+    $this->drupalLogin($this->rootUser);
+
+    // Check that the default field form is visible when no callback is set.
+    $this->drupalGet('/admin/structure/types/manage/article/fields/node.article.field_test');
+    $this->assertSession()->fieldValueEquals('default_value_input[field_test][0][value]', '');
+
+    // Set a different field value, it should be on the field.
+    $default_value = $this->randomString();
+    $field_config->setDefaultValue([['value' => $default_value]])->save();
+    $this->drupalGet('/admin/structure/types/manage/article/fields/node.article.field_test');
+    $this->assertSession()->fieldValueEquals('default_value_input[field_test][0][value]', $default_value);
+
+    // Set a different field value to the field directly, instead of an array.
+    $default_value = $this->randomString();
+    $field_config->setDefaultValue($default_value)->save();
+    $this->drupalGet('/admin/structure/types/manage/article/fields/node.article.field_test');
+    $this->assertSession()->fieldValueEquals('default_value_input[field_test][0][value]', $default_value);
+
+    // Set a default value callback instead, and the default field form should
+    // not be visible.
+    $field_config->setDefaultValueCallback('\Drupal\field_test\FieldDefaultValueCallbackProvider::calculateDefaultValue')->save();
+    $this->drupalGet('/admin/structure/types/manage/article/fields/node.article.field_test');
+    $this->assertSession()->fieldNotExists('default_value_input[field_test][0][value]');
+  }
+
+}

core/modules/field/tests/src/Functional/FieldHelpTest.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests help display for the Field module.
+ *
+ * @group field
+ */
+class FieldHelpTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['field', 'help'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The admin user that will be created.
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create the admin user.
+    $this->adminUser = $this->drupalCreateUser([
+      'access help pages',
+      'view the administration theme',
+    ]);
+  }
+
+  /**
+   * Tests the Field module's help page.
+   */
+  public function testFieldHelp(): void {
+    // Log in the admin user.
+    $this->drupalLogin($this->adminUser);
+
+    // Visit the Help page and make sure no warnings or notices are thrown.
+    $this->drupalGet('admin/help/field');
+
+    // Enable the Options, Email and Field API Test modules.
+    \Drupal::service('module_installer')->install(['options', 'field_test']);
+
+    $this->drupalGet('admin/help/field');
+    $this->assertSession()->linkExists('Options', 0, 'Options module is listed on the Field help page.');
+    // Verify that modules with field types that do not implement hook_help are
+    // listed.
+    $this->assertSession()->pageTextContains('Field API Test');
+    $this->assertSession()->linkNotExists('Field API Test', 'Modules with field types that do not implement hook_help are not linked.');
+    $this->assertSession()->linkNotExists('Link', 'Modules that have not been installed, are not listed.');
+  }
+
+}

core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php

@@ -0,0 +1,147 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests deleting field storage when a module in uninstalled through the UI.
+ *
+ * @group field
+ * @see \Drupal\field\ConfigImporterFieldPurger
+ * @see field_config_import_steps_alter()
+ * @see field_form_config_admin_import_form_alter()
+ */
+class FieldImportDeleteUninstallUiTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'entity_test',
+    'telephone',
+    'config',
+    'filter',
+    'datetime',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser(['synchronize configuration']));
+  }
+
+  /**
+   * Tests deleting field storages and fields as part of config import.
+   */
+  public function testImportDeleteUninstall(): void {
+    // Create a telephone field.
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'field_tel',
+      'entity_type' => 'entity_test',
+      'type' => 'telephone',
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test',
+    ])->save();
+
+    // Create a text field.
+    $date_field_storage = FieldStorageConfig::create([
+      'field_name' => 'field_date',
+      'entity_type' => 'entity_test',
+      'type' => 'datetime',
+    ]);
+    $date_field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $date_field_storage,
+      'bundle' => 'entity_test',
+    ])->save();
+
+    // Create an entity which has values for the telephone and text field.
+    $entity = EntityTest::create();
+    $value = '+0123456789';
+    $entity->field_tel = $value;
+    $entity->field_date = time();
+    $entity->name->value = $this->randomMachineName();
+    $entity->save();
+
+    // Delete the text field before exporting configuration so that we can test
+    // that deleted fields that are provided by modules that will be uninstalled
+    // are also purged and that the UI message includes such fields.
+    $date_field_storage->delete();
+
+    // Verify entity has been created properly.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertEquals($value, $entity->field_tel->value);
+    $this->assertEquals($value, $entity->field_tel[0]->value);
+
+    $active = $this->container->get('config.storage');
+    $sync = $this->container->get('config.storage.sync');
+    $this->copyConfig($active, $sync);
+
+    // Stage uninstall of the Telephone module.
+    $core_extension = $this->config('core.extension')->get();
+    unset($core_extension['module']['telephone']);
+    $sync->write('core.extension', $core_extension);
+
+    // Stage the field deletion including its dependencies.
+    $sync->delete('field.storage.entity_test.field_tel');
+    $sync->delete('field.field.entity_test.entity_test.field_tel');
+    $sync->delete('core.entity_form_display.entity_test.entity_test.default');
+    $this->drupalGet('admin/config/development/configuration');
+    // Test that the message for one field being purged during a configuration
+    // synchronization is correct.
+    $this->assertSession()->pageTextContains('This synchronization will delete data from the field entity_test.field_tel.');
+
+    // Stage an uninstall of the datetime module to test the message for
+    // multiple fields.
+    unset($core_extension['module']['datetime']);
+    $sync->write('core.extension', $core_extension);
+
+    $this->drupalGet('admin/config/development/configuration');
+    $this->assertSession()->pageTextContains('This synchronization will delete data from the fields: entity_test.field_tel, entity_test.field_date.');
+
+    // This will purge all the data, delete the field and uninstall the
+    // Telephone and Text modules.
+    $this->submitForm([], 'Import all');
+    $this->assertSession()->pageTextNotContains('Field data will be deleted by this synchronization.');
+    $this->rebuildContainer();
+    $this->assertFalse(\Drupal::moduleHandler()->moduleExists('telephone'));
+    $this->assertNull(\Drupal::service('entity.repository')->loadEntityByUuid('field_storage_config', $field_storage->uuid()), 'The telephone field has been deleted by the configuration synchronization');
+    $deleted_storages = \Drupal::state()->get('field.storage.deleted', []);
+    $this->assertFalse(isset($deleted_storages[$field_storage->uuid()]), 'Telephone field has been completed removed from the system.');
+    $this->assertFalse(isset($deleted_storages[$field_storage->uuid()]), 'Text field has been completed removed from the system.');
+  }
+
+  /**
+   * Tests if the synchronization form is available when the core.extension.yml is missing.
+   */
+  public function testSynchronizeForm(): void {
+    $sync = $this->container->get('config.storage.sync');
+    $this->copyConfig($this->container->get('config.storage'), $sync);
+
+    $sync->delete('core.extension');
+    $this->drupalGet('admin/config/development/configuration');
+    $assertSession = $this->assertSession();
+    $this->assertSession()->elementExists('css', 'input[value="Import all"]')->click();
+    $assertSession->pageTextContains('The core.extension configuration does not exist.');
+  }
+
+}

core/modules/field/tests/src/Functional/FieldTestBase.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Parent class for Field API tests.
+ */
+abstract class FieldTestBase extends BrowserTestBase {
+
+  /**
+   * Generate random values for a field_test field.
+   *
+   * @param $cardinality
+   *   Number of values to generate.
+   *
+   * @return array
+   *   An array of random values, in the format expected for field values.
+   */
+  public function _generateTestFieldValues($cardinality) {
+    $values = [];
+    for ($i = 0; $i < $cardinality; $i++) {
+      // field_test fields treat 0 as 'empty value'.
+      $values[$i]['value'] = mt_rand(1, 127);
+    }
+    return $values;
+  }
+
+  /**
+   * Assert that a field has the expected values in an entity.
+   *
+   * This function only checks a single column in the field values.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity to test.
+   * @param $field_name
+   *   The name of the field to test
+   * @param $expected_values
+   *   The array of expected values.
+   * @param $langcode
+   *   (Optional) The language code for the values. Defaults to
+   *   \Drupal\Core\Language\LanguageInterface::LANGCODE_DEFAULT.
+   * @param $column
+   *   (Optional) The name of the column to check. Defaults to 'value'.
+   */
+  public function assertFieldValues(EntityInterface $entity, $field_name, $expected_values, $langcode = LanguageInterface::LANGCODE_DEFAULT, $column = 'value') {
+    // Re-load the entity to make sure we have the latest changes.
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($entity->getEntityTypeId());
+    $storage->resetCache([$entity->id()]);
+    $e = $storage->load($entity->id());
+
+    $field = $values = $e->getTranslation($langcode)->$field_name;
+    // Filter out empty values so that they don't mess with the assertions.
+    $field->filterEmptyItems();
+    $values = $field->getValue();
+    $this->assertSameSize($expected_values, $values, 'Expected number of values were saved.');
+    foreach ($expected_values as $key => $value) {
+      $this->assertEquals($value, $values[$key][$column], "Value $value was saved correctly.");
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/FormTest.php

@@ -0,0 +1,771 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Form\FormState;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\entity_test\Entity\EntityTestBaseFieldDisplay;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests field form handling.
+ *
+ * @group field
+ * @group #slow
+ */
+class FormTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * Locale is installed so that TranslatableMarkup actually does something.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'node',
+    'field_test',
+    'options',
+    'entity_test',
+    'locale',
+    'field_ui',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * An array of values defining a field single.
+   *
+   * @var array
+   */
+  protected $fieldStorageSingle;
+
+  /**
+   * An array of values defining a field multiple.
+   *
+   * @var array
+   */
+  protected $fieldStorageMultiple;
+
+  /**
+   * An array of values defining a field with unlimited cardinality.
+   *
+   * @var array
+   */
+  protected $fieldStorageUnlimited;
+
+  /**
+   * An array of values defining a field.
+   *
+   * @var array
+   */
+  protected $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $web_user = $this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'administer entity_test fields',
+    ]);
+    $this->drupalLogin($web_user);
+
+    $this->fieldStorageSingle = [
+      'field_name' => 'field_single',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+    ];
+    $this->fieldStorageMultiple = [
+      'field_name' => 'field_multiple',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => 4,
+    ];
+    $this->fieldStorageUnlimited = [
+      'field_name' => 'field_unlimited',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ];
+
+    $this->field = [
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $this->randomMachineName() . '_label',
+      'description' => '[site:name]_description',
+      'weight' => mt_rand(0, 127),
+      'settings' => [
+        'test_field_setting' => $this->randomMachineName(),
+      ],
+    ];
+  }
+
+  public function testFieldFormSingle(): void {
+    $field_storage = $this->fieldStorageSingle;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+
+    // Create token value expected for description.
+    $token_description = Html::escape($this->config('system.site')->get('name')) . '_description';
+    $this->assertSession()->pageTextContains($token_description);
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[1][value]");
+
+    // Check that hook_field_widget_single_element_form_alter() does not believe
+    // this is the default value form.
+    $this->assertSession()->pageTextNotContains('From hook_field_widget_single_element_form_alter(): Default form is true.');
+    // Check that hook_field_widget_single_element_form_alter() does not believe
+    // this is the default value form.
+    $this->assertSession()->pageTextNotContains('From hook_field_widget_complete_form_alter(): Default form is true.');
+
+    // Submit with invalid value (field-level validation).
+    $edit = [
+      "{$field_name}[0][value]" => -1,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$this->field['label']} does not accept the value -1.");
+    // @todo check that the correct field is flagged for error.
+
+    // Create an entity
+    $value = mt_rand(1, 127);
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $entity = EntityTest::load($id);
+    $this->assertEquals($value, $entity->{$field_name}->value, 'Field value was saved');
+
+    // Display edit form.
+    $this->drupalGet('entity_test/manage/' . $id . '/edit');
+    // Check that the widget is displayed with the correct default value.
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", $value);
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[1][value]");
+
+    // Update the entity.
+    $value = mt_rand(1, 127);
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been updated.');
+    $this->container->get('entity_type.manager')->getStorage('entity_test')->resetCache([$id]);
+    $entity = EntityTest::load($id);
+    $this->assertEquals($value, $entity->{$field_name}->value, 'Field value was updated');
+
+    // Empty the field.
+    $value = '';
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->drupalGet('entity_test/manage/' . $id . '/edit');
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been updated.');
+    $this->container->get('entity_type.manager')->getStorage('entity_test')->resetCache([$id]);
+    $entity = EntityTest::load($id);
+    $this->assertTrue($entity->{$field_name}->isEmpty(), 'Field was emptied');
+  }
+
+  /**
+   * Tests field widget default values on entity forms.
+   */
+  public function testFieldFormDefaultValue(): void {
+    $field_storage = $this->fieldStorageSingle;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    $default = rand(1, 127);
+    $this->field['default_value'] = [['value' => $default]];
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    // Test that the default value is displayed correctly.
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", $default);
+
+    // Try to submit an empty value.
+    $edit = [
+      "{$field_name}[0][value]" => '',
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $entity = EntityTest::load($id);
+    $this->assertTrue($entity->{$field_name}->isEmpty(), 'Field is now empty.');
+  }
+
+  public function testFieldFormSingleRequired(): void {
+    $field_storage = $this->fieldStorageSingle;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    $this->field['required'] = TRUE;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Submit with missing required value.
+    $edit = [];
+    $this->drupalGet('entity_test/add');
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$this->field['label']} field is required.");
+
+    // Create an entity
+    $value = mt_rand(1, 127);
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $entity = EntityTest::load($id);
+    $this->assertEquals($value, $entity->{$field_name}->value, 'Field value was saved');
+
+    // Edit with missing required value.
+    $value = '';
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->drupalGet('entity_test/manage/' . $id . '/edit');
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$this->field['label']} field is required.");
+  }
+
+  public function testFieldFormUnlimited(): void {
+    $field_storage = $this->fieldStorageUnlimited;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Verify that only one "Default value" field
+    // exists on the Manage field display.
+    $this->drupalGet("entity_test/structure/entity_test/fields/entity_test.entity_test.{$field_name}");
+    $this->assertSession()->elementsCount('xpath', "//table[@id='field-unlimited-values']/tbody/tr//input[contains(@class, 'form-text')]", 1);
+
+    // Display creation form -> 1 widget.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[1][value]");
+
+    // Check if aria-describedby attribute is placed on multiple value widgets.
+    $this->assertSession()->elementAttributeContains('xpath', '//table[@id="field-unlimited-values"]', 'aria-describedby', 'edit-field-unlimited--description');
+
+    // Press 'add more' button -> 2 widgets.
+    $this->submitForm([], 'Add another item');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->fieldValueEquals("{$field_name}[1][value]", '');
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[2][value]");
+    // @todo check that non-field inputs are preserved ('title'), etc.
+
+    // Yet another time so that we can play with more values -> 3 widgets.
+    $this->submitForm([], 'Add another item');
+
+    // Prepare values and weights.
+    $count = 3;
+    $delta_range = $count - 1;
+    $values = $weights = $pattern = $expected_values = [];
+    $edit = [];
+    for ($delta = 0; $delta <= $delta_range; $delta++) {
+      // Assign unique random values and weights.
+      do {
+        $value = mt_rand(1, 127);
+      } while (in_array($value, $values));
+      do {
+        $weight = mt_rand(-$delta_range, $delta_range);
+      } while (in_array($weight, $weights));
+      $edit["{$field_name}[$delta][value]"] = $value;
+      $edit["{$field_name}[$delta][_weight]"] = $weight;
+      // We'll need three slightly different formats to check the values.
+      $values[$delta] = $value;
+      $weights[$delta] = $weight;
+      $field_values[$weight]['value'] = (string) $value;
+      $pattern[$weight] = "<input [^>]*value=\"$value\" [^>]*";
+    }
+
+    // Press 'add more' button -> 4 widgets
+    $this->submitForm($edit, 'Add another item');
+    for ($delta = 0; $delta <= $delta_range; $delta++) {
+      $this->assertSession()->fieldValueEquals("{$field_name}[$delta][value]", $values[$delta]);
+      $this->assertSession()->fieldValueEquals("{$field_name}[$delta][_weight]", $weights[$delta]);
+    }
+    ksort($pattern);
+    $pattern = implode('.*', array_values($pattern));
+    // Verify that the widgets are displayed in the correct order.
+    $this->assertSession()->responseMatches("|$pattern|s");
+    $this->assertSession()->fieldValueEquals("{$field_name}[$delta][value]", '');
+    $this->assertSession()->fieldValueEquals("{$field_name}[$delta][_weight]", $delta);
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[" . ($delta + 1) . '][value]');
+
+    // Submit the form and create the entity.
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $entity = EntityTest::load($id);
+    ksort($field_values);
+    $field_values = array_values($field_values);
+    $this->assertSame($field_values, $entity->{$field_name}->getValue(), 'Field values were saved in the correct order');
+
+    // Display edit form: check that the expected number of widgets is
+    // displayed, with correct values change values, reorder, leave an empty
+    // value in the middle.
+    // Submit: check that the entity is updated with correct values
+    // Re-submit: check that the field can be emptied.
+
+    // Test with several multiple fields in a form
+  }
+
+  /**
+   * Tests the position of the required label.
+   */
+  public function testFieldFormUnlimitedRequired(): void {
+    $field_name = $this->fieldStorageUnlimited['field_name'];
+    $this->field['field_name'] = $field_name;
+    $this->field['required'] = TRUE;
+    FieldStorageConfig::create($this->fieldStorageUnlimited)->save();
+    FieldConfig::create($this->field)->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Display creation form -> 1 widget.
+    $this->drupalGet('entity_test/add');
+    // Check that the Required symbol is present for the label of the field
+    // with unlimited cardinality.
+    $this->assertSession()->elementAttributeContains('xpath', "//h4[contains(@class, 'label') and contains(text(), '{$this->field['label']}')]", 'class', 'js-form-required');
+    // Check that the label of the field input is visually hidden and contains
+    // the field title and an indication of the delta for a11y.
+    $this->assertSession()->elementExists('xpath', "//label[@for='edit-field-unlimited-0-value' and contains(@class, 'visually-hidden') and contains(text(), '{$this->field['label']} (value 1)')]");
+  }
+
+  /**
+   * Tests widget handling of multiple required radios.
+   */
+  public function testFieldFormMultivalueWithRequiredRadio(): void {
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Create a multivalue test field.
+    $field_storage = $this->fieldStorageUnlimited;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    $display_repository->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($field_name)
+      ->save();
+
+    // Add a required radio field.
+    FieldStorageConfig::create([
+      'field_name' => 'required_radio_test',
+      'entity_type' => 'entity_test',
+      'type' => 'list_string',
+      'settings' => [
+        'allowed_values' => ['yes' => 'yes', 'no' => 'no'],
+      ],
+    ])->save();
+    $field = [
+      'field_name' => 'required_radio_test',
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'required' => TRUE,
+    ];
+    FieldConfig::create($field)->save();
+    $display_repository->getFormDisplay($field['entity_type'], $field['bundle'])
+      ->setComponent($field['field_name'], [
+        'type' => 'options_buttons',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+
+    // Press the 'Add more' button.
+    $this->submitForm([], 'Add another item');
+
+    // Verify that no error is thrown by the radio element.
+    $this->assertSession()->elementNotExists('xpath', '//div[contains(@class, "error")]');
+
+    // Verify that the widget is added.
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->fieldValueEquals("{$field_name}[1][value]", '');
+    // Verify that no extraneous widget is displayed.
+    $this->assertSession()->fieldNotExists("{$field_name}[2][value]");
+  }
+
+  /**
+   * Tests widgets handling multiple values.
+   */
+  public function testFieldFormMultipleWidget(): void {
+    // Create a field with fixed cardinality, configure the form to use a
+    // "multiple" widget.
+    $field_storage = $this->fieldStorageMultiple;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+    $form = \Drupal::service('entity_display.repository')->getFormDisplay($this->field['entity_type'], $this->field['bundle'], 'default')
+      ->setComponent($field_name, [
+        'type' => 'test_field_widget_multiple',
+      ]);
+    $form->save();
+    $session = $this->assertSession();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals($field_name, '');
+
+    // Create entity with three values.
+    $edit = [
+      $field_name => '1, 2, 3',
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+
+    // Check that the values were saved.
+    $entity_init = EntityTest::load($id);
+    $this->assertFieldValues($entity_init, $field_name, [1, 2, 3]);
+
+    // Display the form, check that the values are correctly filled in.
+    $this->drupalGet('entity_test/manage/' . $id . '/edit');
+    $this->assertSession()->fieldValueEquals($field_name, '1, 2, 3');
+
+    // Submit the form with more values than the field accepts.
+    $edit = [$field_name => '1, 2, 3, 4, 5'];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains('this field cannot hold more than 4 values');
+    // Check that the field values were not submitted.
+    $this->assertFieldValues($entity_init, $field_name, [1, 2, 3]);
+
+    // Check that Attributes are rendered on the multivalue container if it is
+    // a multiple widget form.
+    $form->setComponent($field_name, [
+      'type' => 'entity_reference_autocomplete',
+    ])
+      ->save();
+    $this->drupalGet('entity_test/manage/' . $id . '/edit');
+    $name = str_replace('_', '-', $field_name);
+    $session->responseContains('data-drupal-selector="edit-' . $name . '"');
+  }
+
+  /**
+   * Tests fields with no 'edit' access.
+   */
+  public function testFieldFormAccess(): void {
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $entity_type = 'entity_test_rev';
+    // Create a "regular" field.
+    $field_storage = $this->fieldStorageSingle;
+    $field_storage['entity_type'] = $entity_type;
+    $field_name = $field_storage['field_name'];
+    $field = $this->field;
+    $field['field_name'] = $field_name;
+    $field['entity_type'] = $entity_type;
+    $field['bundle'] = $entity_type;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($field)->save();
+    $display_repository->getFormDisplay($entity_type, $entity_type)
+      ->setComponent($field_name)
+      ->save();
+
+    // Create a field with no edit access. See
+    // field_test_entity_field_access().
+    $field_storage_no_access = [
+      'field_name' => 'field_no_edit_access',
+      'entity_type' => $entity_type,
+      'type' => 'test_field',
+    ];
+    $field_name_no_access = $field_storage_no_access['field_name'];
+    $field_no_access = [
+      'field_name' => $field_name_no_access,
+      'entity_type' => $entity_type,
+      'bundle' => $entity_type,
+      'default_value' => [0 => ['value' => 99]],
+    ];
+    FieldStorageConfig::create($field_storage_no_access)->save();
+    FieldConfig::create($field_no_access)->save();
+    $display_repository->getFormDisplay($field_no_access['entity_type'], $field_no_access['bundle'])
+      ->setComponent($field_name_no_access)
+      ->save();
+
+    // Test that the form structure includes full information for each delta
+    // apart from #access.
+    $entity = $this->container->get('entity_type.manager')
+      ->getStorage($entity_type)
+      ->create(['id' => 0, 'revision_id' => 0]);
+
+    $display = $display_repository->getFormDisplay($entity_type, $entity_type);
+    $form = [];
+    $form_state = new FormState();
+    $display->buildForm($entity, $form, $form_state);
+
+    $this->assertFalse($form[$field_name_no_access]['#access'], 'Field #access is FALSE for the field without edit access.');
+
+    // Display creation form.
+    $this->drupalGet($entity_type . '/add');
+    // Check that the widget is not displayed if field access is denied.
+    $this->assertSession()->fieldNotExists("{$field_name_no_access}[0][value]");
+
+    // Create entity.
+    $edit = [
+      "{$field_name}[0][value]" => 1,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match("|$entity_type/manage/(\d+)|", $this->getUrl(), $match);
+    $id = $match[1];
+
+    // Check that the default value was saved.
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($entity_type);
+    $entity = $storage->load($id);
+    $this->assertEquals(99, $entity->{$field_name_no_access}->value, 'Default value was saved for the field with no edit access.');
+    $this->assertEquals(1, $entity->{$field_name}->value, 'Entered value vas saved for the field with edit access.');
+
+    // Create a new revision.
+    $edit = [
+      "{$field_name}[0][value]" => 2,
+      'revision' => TRUE,
+    ];
+    $this->drupalGet($entity_type . '/manage/' . $id . '/edit');
+    $this->submitForm($edit, 'Save');
+
+    // Check that the new revision has the expected values.
+    $storage->resetCache([$id]);
+    $entity = $storage->load($id);
+    $this->assertEquals(99, $entity->{$field_name_no_access}->value, 'New revision has the expected value for the field with no edit access.');
+    $this->assertEquals(2, $entity->{$field_name}->value, 'New revision has the expected value for the field with edit access.');
+
+    // Check that the revision is also saved in the revisions table.
+    /** @var \Drupal\Core\Entity\RevisionableStorageInterface $storage */
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($entity_type);
+    $entity = $storage->loadRevision($entity->getRevisionId());
+    $this->assertEquals(99, $entity->{$field_name_no_access}->value, 'New revision has the expected value for the field with no edit access.');
+    $this->assertEquals(2, $entity->{$field_name}->value, 'New revision has the expected value for the field with edit access.');
+  }
+
+  /**
+   * Tests hiding a field in a form.
+   */
+  public function testHiddenField(): void {
+    $entity_type = 'entity_test_rev';
+    $field_storage = $this->fieldStorageSingle;
+    $field_storage['entity_type'] = $entity_type;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    $this->field['default_value'] = [0 => ['value' => 99]];
+    $this->field['entity_type'] = $entity_type;
+    $this->field['bundle'] = $entity_type;
+    FieldStorageConfig::create($field_storage)->save();
+    $this->field = FieldConfig::create($this->field);
+    $this->field->save();
+    // We explicitly do not assign a widget in a form display, so the field
+    // stays hidden in forms.
+
+    // Display the entity creation form.
+    $this->drupalGet($entity_type . '/add');
+
+    // Create an entity and test that the default value is assigned correctly to
+    // the field that uses the hidden widget.
+    $this->assertSession()->fieldNotExists("{$field_name}[0][value]");
+    $this->submitForm([], 'Save');
+    preg_match('|' . $entity_type . '/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test_rev ' . $id . ' has been created.');
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($entity_type);
+
+    $entity = $storage->load($id);
+    $this->assertEquals(99, $entity->{$field_name}->value, 'Default value was saved');
+
+    // Update the field to remove the default value, and switch to the default
+    // widget.
+    $this->field->setDefaultValue([]);
+    $this->field->save();
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($entity_type, $this->field->getTargetBundle())
+      ->setComponent($this->field->getName(), [
+        'type' => 'test_field_widget',
+      ])
+      ->save();
+
+    // Display edit form.
+    $this->drupalGet($entity_type . '/manage/' . $id . '/edit');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", 99);
+
+    // Update the entity.
+    $value = mt_rand(1, 127);
+    $edit = ["{$field_name}[0][value]" => $value];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains('entity_test_rev ' . $id . ' has been updated.');
+    $storage->resetCache([$id]);
+    $entity = $storage->load($id);
+    $this->assertEquals($value, $entity->{$field_name}->value, 'Field value was updated');
+
+    // Set the field back to hidden.
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($entity_type, $this->field->getTargetBundle())
+      ->removeComponent($this->field->getName())
+      ->save();
+
+    // Create a new revision.
+    $edit = ['revision' => TRUE];
+    $this->drupalGet($entity_type . '/manage/' . $id . '/edit');
+    $this->submitForm($edit, 'Save');
+
+    // Check that the expected value has been carried over to the new revision.
+    $storage->resetCache([$id]);
+    $entity = $storage->load($id);
+    $this->assertEquals($value, $entity->{$field_name}->value, 'New revision has the expected value for the field with the Hidden widget');
+  }
+
+  /**
+   * Tests the form display of the label for multi-value fields.
+   */
+  public function testLabelOnMultiValueFields(): void {
+    $user = $this->drupalCreateUser(['administer entity_test content']);
+    $this->drupalLogin($user);
+
+    // Ensure that the 'bar' bundle exists, to avoid config validation errors.
+    entity_test_create_bundle('bar', entity_type: 'entity_test_base_field_display');
+
+    FieldStorageConfig::create([
+      'entity_type' => 'entity_test_base_field_display',
+      'field_name' => 'foo',
+      'type' => 'text',
+      'cardinality' => FieldStorageConfig::CARDINALITY_UNLIMITED,
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test_base_field_display',
+      'bundle' => 'bar',
+      'field_name' => 'foo',
+      // Set a dangerous label to test XSS filtering.
+      'label' => "<script>alert('a configurable field');</script>",
+    ])->save();
+    EntityFormDisplay::create([
+      'targetEntityType' => 'entity_test_base_field_display',
+      'bundle' => 'bar',
+      'mode' => 'default',
+    ])->setComponent('foo', ['type' => 'text_textfield'])->enable()->save();
+
+    $entity = EntityTestBaseFieldDisplay::create(['type' => 'bar']);
+    $entity->save();
+
+    $this->drupalGet('entity_test_base_field_display/manage/' . $entity->id());
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->pageTextContains('A field with multiple values');
+    // Test if labels were XSS filtered.
+    $this->assertSession()->assertEscaped("<script>alert('a configurable field');</script>");
+  }
+
+  /**
+   * Tests hook_field_widget_complete_form_alter().
+   */
+  public function testFieldFormMultipleWidgetAlter(): void {
+    $this->widgetAlterTest('hook_field_widget_complete_form_alter', 'test_field_widget_multiple');
+  }
+
+  /**
+   * Tests hook_field_widget_complete_form_alter() with single value elements.
+   */
+  public function testFieldFormMultipleWidgetAlterSingleValues(): void {
+    $this->widgetAlterTest('hook_field_widget_complete_form_alter', 'test_field_widget_multiple_single_value');
+  }
+
+  /**
+   * Tests hook_field_widget_complete_WIDGET_TYPE_form_alter().
+   */
+  public function testFieldFormMultipleWidgetTypeAlter(): void {
+    $this->widgetAlterTest('hook_field_widget_complete_WIDGET_TYPE_form_alter', 'test_field_widget_multiple');
+  }
+
+  /**
+   * Tests hook_field_widget_complete_WIDGET_TYPE_form_alter() with single value elements.
+   */
+  public function testFieldFormMultipleWidgetTypeAlterSingleValues(): void {
+    $this->widgetAlterTest('hook_field_widget_complete_WIDGET_TYPE_form_alter', 'test_field_widget_multiple_single_value');
+  }
+
+  /**
+   * Tests widget alter hooks for a given hook name.
+   */
+  protected function widgetAlterTest($hook, $widget) {
+    // Create a field with fixed cardinality, configure the form to use a
+    // "multiple" widget.
+    $field_storage = $this->fieldStorageMultiple;
+    $field_name = $field_storage['field_name'];
+    $this->field['field_name'] = $field_name;
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($this->field)->save();
+
+    // Set a flag in state so that the hook implementations will run.
+    \Drupal::state()->set("field_test.widget_alter_test", [
+      'hook' => $hook,
+      'field_name' => $field_name,
+      'widget' => $widget,
+    ]);
+    \Drupal::service('entity_display.repository')->getFormDisplay($this->field['entity_type'], $this->field['bundle'], 'default')
+      ->setComponent($field_name, [
+        'type' => $widget,
+      ])
+      ->save();
+
+    // We need to rebuild hook information after setting the component through
+    // the API.
+    $this->rebuildAll();
+
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->pageTextMatchesCount(1, '/From ' . $hook . '.* prefix on ' . $field_name . ' parent element\./');
+    if ($widget === 'test_field_widget_multiple_single_value') {
+      $suffix_text = "From $hook(): suffix on $field_name child element.";
+      $this->assertEquals($field_storage['cardinality'], substr_count($this->getTextContent(), $suffix_text), "'$suffix_text' was found {$field_storage['cardinality']} times  using widget $widget");
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/FunctionalString/StringFieldTest.php

@@ -0,0 +1,120 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\FunctionalString;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the creation of string fields.
+ *
+ * @group text
+ */
+class StringFieldTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['entity_test', 'file'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * A user without any special permissions.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $webUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->webUser = $this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'access content',
+    ]);
+    $this->drupalLogin($this->webUser);
+  }
+
+  // Test fields.
+
+  /**
+   * Tests widgets.
+   */
+  public function testTextfieldWidgets(): void {
+    $this->_testTextfieldWidgets('string', 'string_textfield');
+    $this->_testTextfieldWidgets('string_long', 'string_textarea');
+  }
+
+  /**
+   * Helper function for testTextfieldWidgets().
+   */
+  public function _testTextfieldWidgets($field_type, $widget_type) {
+    // Create a field.
+    $field_name = $this->randomMachineName();
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => $field_type,
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test',
+      'label' => $this->randomMachineName() . '_label',
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => $widget_type,
+        'settings' => [
+          'placeholder' => 'A placeholder on ' . $widget_type,
+        ],
+      ])
+      ->save();
+    $display_repository->getViewDisplay('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name)
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->fieldNotExists("{$field_name}[0][format]");
+    $this->assertSession()->responseContains(new FormattableMarkup('placeholder="A placeholder on @widget_type"', ['@widget_type' => $widget_type]));
+
+    // Submit with some value.
+    $value = $this->randomMachineName();
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+
+    // Display the entity.
+    $entity = EntityTest::load($id);
+    $display = $display_repository->getViewDisplay($entity->getEntityTypeId(), $entity->bundle(), 'full');
+    $content = $display->build($entity);
+    $rendered_entity = \Drupal::service('renderer')->renderRoot($content);
+    $this->assertStringContainsString($value, (string) $rendered_entity);
+  }
+
+}

core/modules/field/tests/src/Functional/GenericTest.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\Tests\system\Functional\Module\GenericModuleTestBase;
+
+/**
+ * Generic module test for field.
+ *
+ * @group field
+ */
+class GenericTest extends GenericModuleTestBase {}

core/modules/field/tests/src/Functional/NestedFormTest.php

@@ -0,0 +1,233 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests field elements in nested forms.
+ *
+ * @group field
+ */
+class NestedFormTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['field_test', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * @var array
+   */
+  protected array $fieldStorageSingle;
+
+  /**
+   * @var array
+   */
+  protected array $fieldStorageUnlimited;
+
+  /**
+   * @var array
+   */
+  protected array $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $web_user = $this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+    ]);
+    $this->drupalLogin($web_user);
+
+    $this->fieldStorageSingle = [
+      'field_name' => 'field_single',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+    ];
+    $this->fieldStorageUnlimited = [
+      'field_name' => 'field_unlimited',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ];
+
+    $this->field = [
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $this->randomMachineName() . '_label',
+      'description' => '[site:name]_description',
+      'weight' => mt_rand(0, 127),
+      'settings' => [
+        'test_field_setting' => $this->randomMachineName(),
+      ],
+    ];
+  }
+
+  /**
+   * Tests Field API form integration within a subform.
+   */
+  public function testNestedFieldForm(): void {
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Add two fields on the 'entity_test'
+    FieldStorageConfig::create($this->fieldStorageSingle)->save();
+    FieldStorageConfig::create($this->fieldStorageUnlimited)->save();
+    $this->field['field_name'] = 'field_single';
+    $this->field['label'] = 'Single field';
+    FieldConfig::create($this->field)->save();
+    $display_repository->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($this->field['field_name'])
+      ->save();
+    $this->field['field_name'] = 'field_unlimited';
+    $this->field['label'] = 'Unlimited field';
+    FieldConfig::create($this->field)->save();
+    $display_repository->getFormDisplay($this->field['entity_type'], $this->field['bundle'])
+      ->setComponent($this->field['field_name'])
+      ->save();
+
+    // Create two entities.
+    $entity_type = 'entity_test';
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($entity_type);
+
+    $entity_1 = $storage->create(['id' => 1]);
+    $entity_1->enforceIsNew();
+    $entity_1->field_single->value = 1;
+    $entity_1->field_unlimited->value = 2;
+    $entity_1->save();
+
+    $entity_2 = $storage->create(['id' => 2]);
+    $entity_2->enforceIsNew();
+    $entity_2->field_single->value = 10;
+    $entity_2->field_unlimited->value = 11;
+    $entity_2->save();
+
+    // Display the 'combined form'.
+    $this->drupalGet('test-entity/nested/1/2');
+    $this->assertSession()->fieldValueEquals('field_single[0][value]', 1);
+    $this->assertSession()->fieldValueEquals('field_unlimited[0][value]', 2);
+    $this->assertSession()->fieldValueEquals('entity_2[field_single][0][value]', 10);
+    $this->assertSession()->fieldValueEquals('entity_2[field_unlimited][0][value]', 11);
+
+    // Submit the form and check that the entities are updated accordingly.
+    $edit = [
+      'field_single[0][value]' => 1,
+      'field_unlimited[0][value]' => 2,
+      'field_unlimited[1][value]' => 3,
+      'entity_2[field_single][0][value]' => 11,
+      'entity_2[field_unlimited][0][value]' => 12,
+      'entity_2[field_unlimited][1][value]' => 13,
+    ];
+    $this->submitForm($edit, 'Save');
+    $entity_1 = $storage->load(1);
+    $entity_2 = $storage->load(2);
+    $this->assertFieldValues($entity_1, 'field_single', [1]);
+    $this->assertFieldValues($entity_1, 'field_unlimited', [2, 3]);
+    $this->assertFieldValues($entity_2, 'field_single', [11]);
+    $this->assertFieldValues($entity_2, 'field_unlimited', [12, 13]);
+
+    // Submit invalid values and check that errors are reported on the
+    // correct widgets.
+    $edit = [
+      'field_unlimited[1][value]' => -1,
+    ];
+    $this->drupalGet('test-entity/nested/1/2');
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("Unlimited field does not accept the value -1.");
+    // Entity 1: check that the error was flagged on the correct element.
+    $error_field = $this->assertSession()->fieldExists('edit-field-unlimited-1-value');
+    $this->assertTrue($error_field->hasClass('error'));
+    $edit = [
+      'entity_2[field_unlimited][1][value]' => -1,
+    ];
+    $this->drupalGet('test-entity/nested/1/2');
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("Unlimited field does not accept the value -1.");
+    // Entity 2: check that the error was flagged on the correct element.
+    $error_field = $this->assertSession()->fieldExists('edit-entity-2-field-unlimited-1-value');
+    $this->assertTrue($error_field->hasClass('error'));
+
+    // Test that reordering works on both entities.
+    $edit = [
+      'field_unlimited[0][_weight]' => 0,
+      'field_unlimited[1][_weight]' => -1,
+      'entity_2[field_unlimited][0][_weight]' => 0,
+      'entity_2[field_unlimited][1][_weight]' => -1,
+    ];
+    $this->drupalGet('test-entity/nested/1/2');
+    $this->submitForm($edit, 'Save');
+    $this->assertFieldValues($entity_1, 'field_unlimited', [3, 2]);
+    $this->assertFieldValues($entity_2, 'field_unlimited', [13, 12]);
+
+    // Test the 'add more' buttons.
+    // 'Add more' button in the first entity:
+    $this->drupalGet('test-entity/nested/1/2');
+    $this->submitForm([], 'field_unlimited_add_more');
+    $this->assertSession()->fieldValueEquals('field_unlimited[0][value]', 3);
+    $this->assertSession()->fieldValueEquals('field_unlimited[1][value]', 2);
+    $this->assertSession()->fieldValueEquals('field_unlimited[2][value]', '');
+    $this->assertSession()->fieldValueEquals('field_unlimited[3][value]', '');
+    // 'Add more' button in the first entity (changing field values):
+    $edit = [
+      'entity_2[field_unlimited][0][value]' => 13,
+      'entity_2[field_unlimited][1][value]' => 14,
+      'entity_2[field_unlimited][2][value]' => 15,
+    ];
+    $this->submitForm($edit, 'entity_2_field_unlimited_add_more');
+    $this->assertSession()->fieldValueEquals('entity_2[field_unlimited][0][value]', 13);
+    $this->assertSession()->fieldValueEquals('entity_2[field_unlimited][1][value]', 14);
+    $this->assertSession()->fieldValueEquals('entity_2[field_unlimited][2][value]', 15);
+    $this->assertSession()->fieldValueEquals('entity_2[field_unlimited][3][value]', '');
+    // Save the form and check values are saved correctly.
+    $this->submitForm([], 'Save');
+    $this->assertFieldValues($entity_1, 'field_unlimited', [3, 2]);
+    $this->assertFieldValues($entity_2, 'field_unlimited', [13, 14, 15]);
+  }
+
+  /**
+   * Tests entity level validation within subforms.
+   */
+  public function testNestedEntityFormEntityLevelValidation(): void {
+    // Create two entities.
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage('entity_test_constraints');
+
+    $entity_1 = $storage->create();
+    $entity_1->save();
+
+    $entity_2 = $storage->create();
+    $entity_2->save();
+
+    $page = $this->getSession()->getPage();
+    $assert_session = $this->assertSession();
+
+    // Display the 'combined form'.
+    $this->drupalGet("test-entity-constraints/nested/{$entity_1->id()}/{$entity_2->id()}");
+    $assert_session->hiddenFieldValueEquals('entity_2[changed]', (string) \Drupal::time()->getRequestTime());
+
+    // Submit the form and check that the entities are updated accordingly.
+    $assert_session->hiddenFieldExists('entity_2[changed]')
+      ->setValue(\Drupal::time()->getRequestTime() - 86400);
+    $page->pressButton('Save');
+
+    $elements = $this->cssSelect('.entity-2.error');
+    $this->assertCount(1, $elements, 'The whole nested entity form has been correctly flagged with an error class.');
+  }
+
+}

core/modules/field/tests/src/Functional/Number/NumberFieldTest.php

@@ -0,0 +1,468 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Number;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\FieldConfigInterface;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the creation of numeric fields.
+ *
+ * @group field
+ * @group #slow
+ */
+class NumberFieldTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'administer content types',
+      'administer node fields',
+      'administer node display',
+      'bypass node access',
+      'administer entity_test fields',
+    ]));
+  }
+
+  /**
+   * Tests decimal field.
+   */
+  public function testNumberDecimalField(): void {
+    // Create a field with settings to validate.
+    $field_name = $this->randomMachineName();
+    FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'decimal',
+      'settings' => ['precision' => 8, 'scale' => 4],
+    ])->save();
+    FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number',
+        'settings' => [
+          'placeholder' => '0.00',
+        ],
+      ])
+      ->save();
+    $display_repository->getViewDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number_decimal',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->responseContains('placeholder="0.00"');
+
+    // Submit a signed decimal value within the allowed precision and scale.
+    $value = '-1234.5678';
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $this->assertSession()->responseContains($value);
+
+    // Try to create entries with more than one decimal separator; assert fail.
+    $wrong_entries = [
+      '3.14.159',
+      '0..45469',
+      '..4589',
+      '6.459.52',
+      '6.3..25',
+    ];
+
+    foreach ($wrong_entries as $wrong_entry) {
+      $this->drupalGet('entity_test/add');
+      $edit = [
+        "{$field_name}[0][value]" => $wrong_entry,
+      ];
+      $this->submitForm($edit, 'Save');
+      $this->assertSession()->pageTextContains("{$field_name} must be a number.");
+    }
+
+    // Try to create entries with minus sign not in the first position.
+    $wrong_entries = [
+      '3-3',
+      '4-',
+      '1.3-',
+      '1.2-4',
+      '-10-10',
+    ];
+
+    foreach ($wrong_entries as $wrong_entry) {
+      $this->drupalGet('entity_test/add');
+      $edit = [
+        "{$field_name}[0][value]" => $wrong_entry,
+      ];
+      $this->submitForm($edit, 'Save');
+      $this->assertSession()->pageTextContains("{$field_name} must be a number.");
+    }
+  }
+
+  /**
+   * Tests integer field.
+   */
+  public function testNumberIntegerField(): void {
+    $minimum = rand(-4000, -2000);
+    $maximum = rand(2000, 4000);
+
+    // Create a field with settings to validate.
+    $field_name = $this->randomMachineName();
+    $storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'integer',
+    ]);
+    $storage->save();
+
+    FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'settings' => [
+        'min' => $minimum,
+        'max' => $maximum,
+        'prefix' => 'ThePrefix',
+      ],
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number',
+        'settings' => [
+          'placeholder' => '4',
+        ],
+      ])
+      ->save();
+    $display_repository->getViewDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number_integer',
+        'settings' => [
+          'prefix_suffix' => FALSE,
+        ],
+      ])
+      ->save();
+
+    // Check the storage schema.
+    $expected = [
+      'columns' => [
+        'value' => [
+          'type' => 'int',
+          'unsigned' => '',
+          'size' => 'normal',
+        ],
+      ],
+      'unique keys' => [],
+      'indexes' => [],
+      'foreign keys' => [],
+    ];
+    $this->assertEquals($expected, $storage->getSchema());
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->responseContains('placeholder="4"');
+
+    // Submit a valid integer
+    $value = rand($minimum, $maximum);
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+
+    // Try to set a value below the minimum value
+    $this->drupalGet('entity_test/add');
+    $edit = [
+      "{$field_name}[0][value]" => $minimum - 1,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$field_name} must be higher than or equal to {$minimum}.");
+
+    // Try to set a decimal value
+    $this->drupalGet('entity_test/add');
+    $edit = [
+      "{$field_name}[0][value]" => 1.5,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$field_name} is not a valid number.");
+
+    // Try to set a value above the maximum value
+    $this->drupalGet('entity_test/add');
+    $edit = [
+      "{$field_name}[0][value]" => $maximum + 1,
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$field_name} must be lower than or equal to {$maximum}.");
+
+    // Try to set a wrong integer value.
+    $this->drupalGet('entity_test/add');
+    $edit = [
+      "{$field_name}[0][value]" => '20-40',
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains("{$field_name} must be a number.");
+
+    // Test with valid entries.
+    $valid_entries = [
+      '-1234',
+      '0',
+      '1234',
+    ];
+
+    foreach ($valid_entries as $valid_entry) {
+      $this->drupalGet('entity_test/add');
+      $edit = [
+        "{$field_name}[0][value]" => $valid_entry,
+      ];
+      $this->submitForm($edit, 'Save');
+      preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+      $id = $match[1];
+      $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+      $this->assertSession()->responseContains($valid_entry);
+      // Verify that the "content" attribute is not present since the Prefix is
+      // not being displayed.
+      $this->assertSession()->elementNotExists('xpath', '//div[@content="' . $valid_entry . '"]');
+    }
+
+    // Test for the content attribute when a Prefix is displayed. Presumably this also tests for the attribute when a Suffix is displayed.
+    $display_repository->getViewDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number_integer',
+        'settings' => [
+          'prefix_suffix' => TRUE,
+        ],
+      ])
+      ->save();
+    $integer_value = '123';
+    $this->drupalGet('entity_test/add');
+    $edit = [
+      "{$field_name}[0][value]" => $integer_value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+    $this->drupalGet('entity_test/' . $id);
+    // Verify that the "content" attribute has been set to the value of the
+    // field, and the prefix is being displayed.
+    $this->assertSession()->elementTextContains('xpath', '//div[@content="' . $integer_value . '"]', 'ThePrefix' . $integer_value);
+
+    $field_configuration_url = 'entity_test/structure/entity_test/fields/entity_test.entity_test.' . $field_name;
+    $this->drupalGet($field_configuration_url);
+
+    // Tests Number validation messages.
+    $edit = [
+      'settings[min]' => 10,
+      'settings[max]' => 8,
+    ];
+    $this->submitForm($edit, 'Save settings');
+    $this->assertSession()->pageTextContains("The minimum value must be less than or equal to {$edit['settings[max]']}.");
+  }
+
+  /**
+   * Tests float field.
+   */
+  public function testNumberFloatField(): void {
+    // Create a field with settings to validate.
+    $field_name = $this->randomMachineName();
+    FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'float',
+    ])->save();
+
+    FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    $display_repository->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number',
+        'settings' => [
+          'placeholder' => '0.00',
+        ],
+      ])
+      ->save();
+
+    $display_repository->getViewDisplay('entity_test', 'entity_test')
+      ->setComponent($field_name, [
+        'type' => 'number_decimal',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertSession()->fieldValueEquals("{$field_name}[0][value]", '');
+    $this->assertSession()->responseContains('placeholder="0.00"');
+
+    // Submit a signed decimal value within the allowed precision and scale.
+    $value = -1234.5678;
+    $edit = [
+      "{$field_name}[0][value]" => $value,
+    ];
+    $this->submitForm($edit, 'Save');
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertSession()->pageTextContains('entity_test ' . $id . ' has been created.');
+
+    // Ensure that the 'number_decimal' formatter displays the number with the
+    // expected rounding.
+    $this->drupalGet('entity_test/' . $id);
+    $this->assertSession()->responseContains(round($value, 2));
+
+    // Try to create entries with more than one decimal separator; assert fail.
+    $wrong_entries = [
+      '3.14.159',
+      '0..45469',
+      '..4589',
+      '6.459.52',
+      '6.3..25',
+    ];
+
+    foreach ($wrong_entries as $wrong_entry) {
+      $this->drupalGet('entity_test/add');
+      $edit = [
+        "{$field_name}[0][value]" => $wrong_entry,
+      ];
+      $this->submitForm($edit, 'Save');
+      $this->assertSession()->pageTextContains("{$field_name} must be a number.");
+    }
+
+    // Try to create entries with minus sign not in the first position.
+    $wrong_entries = [
+      '3-3',
+      '4-',
+      '1.3-',
+      '1.2-4',
+      '-10-10',
+    ];
+
+    foreach ($wrong_entries as $wrong_entry) {
+      $this->drupalGet('entity_test/add');
+      $edit = [
+        "{$field_name}[0][value]" => $wrong_entry,
+      ];
+      $this->submitForm($edit, 'Save');
+      $this->assertSession()->pageTextContains("{$field_name} must be a number.");
+    }
+  }
+
+  /**
+   * Tests setting the minimum value of a float field through the interface.
+   */
+  public function testCreateNumberFloatField(): void {
+    // Create a float field.
+    $field_name = $this->randomMachineName();
+    FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'float',
+    ])->save();
+
+    $field = FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+    ]);
+    $field->save();
+
+    // Set the minimum value to a float value.
+    $this->assertSetMinimumValue($field, 0.0001);
+    // Set the minimum value to an integer value.
+    $this->assertSetMinimumValue($field, 1);
+  }
+
+  /**
+   * Tests setting the minimum value of a decimal field through the interface.
+   */
+  public function testCreateNumberDecimalField(): void {
+    // Create a decimal field.
+    $field_name = $this->randomMachineName();
+    FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'decimal',
+    ])->save();
+
+    $field = FieldConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+    ]);
+    $field->save();
+
+    // Set the minimum value to a decimal value.
+    $this->assertSetMinimumValue($field, 0.1);
+    // Set the minimum value to an integer value.
+    $this->assertSetMinimumValue($field, 1);
+  }
+
+  /**
+   * Helper function to set the minimum value of a field.
+   *
+   * @internal
+   */
+  public function assertSetMinimumValue(FieldConfigInterface $field, $minimum_value): void {
+    $field_configuration_url = 'entity_test/structure/entity_test/fields/entity_test.entity_test.' . $field->getName();
+
+    // Set the minimum value.
+    $edit = [
+      'settings[min]' => $minimum_value,
+    ];
+    $this->drupalGet($field_configuration_url);
+    $this->submitForm($edit, 'Save settings');
+    // Check if an error message is shown.
+    $this->assertSession()->pageTextNotContains("Minimum is not a valid number.");
+    // Check if a success message is shown.
+    $this->assertSession()->pageTextContains("Saved {$field->getLabel()} configuration.");
+    // Check if the minimum value was actually set.
+    $this->drupalGet($field_configuration_url);
+    $this->assertSession()->fieldValueEquals('edit-settings-min', $minimum_value);
+  }
+
+}

core/modules/field/tests/src/Functional/ReEnableModuleFieldTest.php

@@ -0,0 +1,144 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\Tests\Traits\Core\CronRunTrait;
+
+/**
+ * Tests the behavior of a field module after being disabled and re-enabled.
+ *
+ * @group field
+ */
+class ReEnableModuleFieldTest extends BrowserTestBase {
+
+  use CronRunTrait;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'field',
+    'node',
+    // We use telephone module instead of test_field because test_field is
+    // hidden and does not display on the admin/modules page.
+    'telephone',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalCreateContentType(['type' => 'article']);
+    $this->drupalLogin($this->drupalCreateUser([
+      'create article content',
+      'edit own article content',
+    ]));
+  }
+
+  /**
+   * Tests the behavior of a field module after being disabled and re-enabled.
+   *
+   * @see field_system_info_alter()
+   */
+  public function testReEnabledField(): void {
+    // Add a telephone field to the article content type.
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'field_telephone',
+      'entity_type' => 'node',
+      'type' => 'telephone',
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'article',
+      'label' => 'Telephone Number',
+    ])->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+    $display_repository->getFormDisplay('node', 'article')
+      ->setComponent('field_telephone', [
+        'type' => 'telephone_default',
+        'settings' => [
+          'placeholder' => '123-456-7890',
+        ],
+      ])
+      ->save();
+
+    $display_repository->getViewDisplay('node', 'article')
+      ->setComponent('field_telephone', [
+        'type' => 'telephone_link',
+        'weight' => 1,
+      ])
+      ->save();
+
+    // Display the article node form and verify the telephone widget is present.
+    $this->drupalGet('node/add/article');
+    $this->assertSession()->fieldValueEquals("field_telephone[0][value]", '');
+
+    // Submit an article node with a telephone field so data exist for the
+    // field.
+    $edit = [
+      'title[0][value]' => $this->randomMachineName(),
+      'field_telephone[0][value]' => "123456789",
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->responseContains('<a href="tel:123456789">');
+
+    // Test that the module can't be uninstalled from the UI while there is data
+    // for its fields.
+    $admin_user = $this->drupalCreateUser([
+      'access administration pages',
+      'administer modules',
+    ]);
+    $this->drupalLogin($admin_user);
+    $this->drupalGet('admin/modules/uninstall');
+    $this->assertSession()->pageTextContains("The Telephone number field type is used in the following field: node.field_telephone");
+
+    // Add another telephone field to a different entity type in order to test
+    // the message for the case when multiple fields are blocking the
+    // uninstallation of a module.
+    $field_storage2 = FieldStorageConfig::create([
+      'field_name' => 'field_telephone_2',
+      'entity_type' => 'user',
+      'type' => 'telephone',
+    ]);
+    $field_storage2->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage2,
+      'bundle' => 'user',
+      'label' => 'User Telephone Number',
+    ])->save();
+
+    $this->drupalGet('admin/modules/uninstall');
+    $this->assertSession()->pageTextContains("The Telephone number field type is used in the following fields: node.field_telephone, user.field_telephone_2");
+
+    // Delete both fields.
+    $field_storage->delete();
+    $field_storage2->delete();
+
+    $this->drupalGet('admin/modules/uninstall');
+    $this->assertSession()->pageTextContains('Uninstall');
+    $this->assertSession()->pageTextContains('Fields pending deletion');
+    $this->cronRun();
+    $this->drupalGet('admin/modules/uninstall');
+    $this->assertSession()->pageTextContains('Uninstall');
+    $this->assertSession()->pageTextNotContains("The Telephone number field type is used in the following field: node.field_telephone");
+    $this->assertSession()->pageTextNotContains('Fields pending deletion');
+  }
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigJsonAnonTest.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigJsonAnonTest extends FieldConfigResourceTestBase {
+
+  use AnonResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigJsonBasicAuthTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigJsonBasicAuthTest extends FieldConfigResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigJsonCookieTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigJsonCookieTest extends FieldConfigResourceTestBase {
+
+  use CookieResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigResourceTestBase.php

@@ -0,0 +1,120 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\node\Entity\NodeType;
+use Drupal\Tests\rest\Functional\EntityResource\ConfigEntityResourceTestBase;
+
+abstract class FieldConfigResourceTestBase extends ConfigEntityResourceTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field', 'field_ui', 'node'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $entityTypeId = 'field_config';
+
+  /**
+   * @var \Drupal\field\FieldConfigInterface
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpAuthorization($method) {
+    $this->grantPermissionsToTestedRole(['administer node fields']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    $camelids = NodeType::create([
+      'name' => 'Camelids',
+      'type' => 'camelids',
+    ]);
+    $camelids->save();
+
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'field_llama',
+      'entity_type' => 'node',
+      'type' => 'text',
+    ]);
+    $field_storage->save();
+
+    $entity = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'camelids',
+    ]);
+    $entity->save();
+
+    return $entity;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedNormalizedEntity() {
+    return [
+      'bundle' => 'camelids',
+      'default_value' => [],
+      'default_value_callback' => '',
+      'dependencies' => [
+        'config' => [
+          'field.storage.node.field_llama',
+          'node.type.camelids',
+        ],
+        'module' => [
+          'text',
+        ],
+      ],
+      'description' => '',
+      'entity_type' => 'node',
+      'field_name' => 'field_llama',
+      'field_type' => 'text',
+      'id' => 'node.camelids.field_llama',
+      'label' => 'field_llama',
+      'langcode' => 'en',
+      'required' => FALSE,
+      'settings' => [
+        'allowed_formats' => [],
+      ],
+      'status' => TRUE,
+      'translatable' => TRUE,
+      'uuid' => $this->entity->uuid(),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNormalizedPostEntity() {
+    // @todo Update in https://www.drupal.org/node/2300677.
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedCacheContexts() {
+    return [
+      'user.permissions',
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedUnauthorizedAccessMessage($method) {
+    return "The 'administer node fields' permission is required.";
+  }
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigXmlAnonTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigXmlAnonTest extends FieldConfigResourceTestBase {
+
+  use AnonResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigXmlBasicAuthTest.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigXmlBasicAuthTest extends FieldConfigResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldConfigXmlCookieTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldConfigXmlCookieTest extends FieldConfigResourceTestBase {
+
+  use CookieResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonAnonTest.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigJsonAnonTest extends FieldStorageConfigResourceTestBase {
+
+  use AnonResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonBasicAuthTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigJsonBasicAuthTest extends FieldStorageConfigResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonCookieTest.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigJsonCookieTest extends FieldStorageConfigResourceTestBase {
+
+  use CookieResourceTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'application/json';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigResourceTestBase.php

@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\rest\Functional\EntityResource\ConfigEntityResourceTestBase;
+
+abstract class FieldStorageConfigResourceTestBase extends ConfigEntityResourceTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field_ui', 'node'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $entityTypeId = 'field_storage_config';
+
+  /**
+   * @var \Drupal\field\FieldConfigStorage
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpAuthorization($method) {
+    $this->grantPermissionsToTestedRole(['administer node fields']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'true_llama',
+      'entity_type' => 'node',
+      'type' => 'boolean',
+    ]);
+    $field_storage->save();
+    return $field_storage;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedNormalizedEntity() {
+    return [
+      'cardinality' => 1,
+      'custom_storage' => FALSE,
+      'dependencies' => [
+        'module' => ['node'],
+      ],
+      'entity_type' => 'node',
+      'field_name' => 'true_llama',
+      'id' => 'node.true_llama',
+      'indexes' => [],
+      'langcode' => 'en',
+      'locked' => FALSE,
+      'module' => 'core',
+      'persist_with_no_fields' => FALSE,
+      'settings' => [],
+      'status' => TRUE,
+      'translatable' => TRUE,
+      'type' => 'boolean',
+      'uuid' => $this->entity->uuid(),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNormalizedPostEntity() {
+    // @todo Update in https://www.drupal.org/node/2300677.
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedUnauthorizedAccessMessage($method) {
+    switch ($method) {
+      case 'GET':
+        return "The 'administer node fields' permission is required.";
+
+      default:
+        return parent::getExpectedUnauthorizedAccessMessage($method);
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlAnonTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\AnonResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigXmlAnonTest extends FieldStorageConfigResourceTestBase {
+
+  use AnonResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlBasicAuthTest.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigXmlBasicAuthTest extends FieldStorageConfigResourceTestBase {
+
+  use BasicAuthResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['basic_auth'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'basic_auth';
+
+}

core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlCookieTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\CookieResourceTestTrait;
+use Drupal\Tests\rest\Functional\EntityResource\XmlEntityNormalizationQuirksTrait;
+
+/**
+ * @group rest
+ */
+class FieldStorageConfigXmlCookieTest extends FieldStorageConfigResourceTestBase {
+
+  use CookieResourceTestTrait;
+  use XmlEntityNormalizationQuirksTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $format = 'xml';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $mimeType = 'text/xml; charset=UTF-8';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $auth = 'cookie';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+}

core/modules/field/tests/src/Functional/TranslationWebTest.php

@@ -0,0 +1,153 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional;
+
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\language\Entity\ConfigurableLanguage;
+
+/**
+ * Tests multilingual fields logic that require a full environment.
+ *
+ * @group field
+ */
+class TranslationWebTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['language', 'field_test', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of the field to use in this test.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * The name of the entity type to use in this test.
+   *
+   * @var string
+   */
+  protected $entityTypeId = 'entity_test_mulrev';
+
+  /**
+   * The field storage to use in this test.
+   *
+   * @var \Drupal\field\Entity\FieldStorageConfig
+   */
+  protected $fieldStorage;
+
+  /**
+   * The field to use in this test.
+   *
+   * @var \Drupal\field\Entity\FieldConfig
+   */
+  protected $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->fieldName = $this->randomMachineName() . '_field_name';
+
+    $field_storage = [
+      'field_name' => $this->fieldName,
+      'entity_type' => $this->entityTypeId,
+      'type' => 'test_field',
+      'cardinality' => 4,
+    ];
+    FieldStorageConfig::create($field_storage)->save();
+    $this->fieldStorage = FieldStorageConfig::load($this->entityTypeId . '.' . $this->fieldName);
+
+    $field = [
+      'field_storage' => $this->fieldStorage,
+      'bundle' => $this->entityTypeId,
+    ];
+    FieldConfig::create($field)->save();
+    $this->field = FieldConfig::load($this->entityTypeId . '.' . $field['bundle'] . '.' . $this->fieldName);
+
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay($this->entityTypeId, $this->entityTypeId)
+      ->setComponent($this->fieldName)
+      ->save();
+
+    for ($i = 0; $i < 3; ++$i) {
+      ConfigurableLanguage::create([
+        'id' => 'l' . $i,
+        'label' => $this->randomString(),
+      ])->save();
+    }
+  }
+
+  /**
+   * Tests field translations when creating a new revision.
+   */
+  public function testFieldFormTranslationRevisions(): void {
+    $web_user = $this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+    ]);
+    $this->drupalLogin($web_user);
+
+    // Prepare the field translations.
+    field_test_entity_info_translatable($this->entityTypeId, TRUE);
+    $entity = $this->container->get('entity_type.manager')
+      ->getStorage($this->entityTypeId)
+      ->create();
+    $available_langcodes = array_flip(array_keys($this->container->get('language_manager')->getLanguages()));
+    $field_name = $this->fieldStorage->getName();
+
+    // Store the field translations.
+    ksort($available_langcodes);
+    $entity->langcode->value = key($available_langcodes);
+    foreach ($available_langcodes as $langcode => $value) {
+      $translation = $entity->hasTranslation($langcode) ? $entity->getTranslation($langcode) : $entity->addTranslation($langcode);
+      $translation->{$field_name}->value = $value + 1;
+    }
+    $entity->save();
+
+    // Create a new revision.
+    $edit = [
+      "{$field_name}[0][value]" => $entity->{$field_name}->value,
+      'revision' => TRUE,
+    ];
+    $this->drupalGet($this->entityTypeId . '/manage/' . $entity->id() . '/edit');
+    $this->submitForm($edit, 'Save');
+
+    // Check translation revisions.
+    $this->checkTranslationRevisions($entity->id(), $entity->getRevisionId(), $available_langcodes);
+    $this->checkTranslationRevisions($entity->id(), $entity->getRevisionId() + 1, $available_langcodes);
+  }
+
+  /**
+   * Tests translation revisions.
+   *
+   * Check if the field translation attached to the entity revision identified
+   * by the passed arguments were correctly stored.
+   */
+  private function checkTranslationRevisions($id, $revision_id, $available_langcodes) {
+    $field_name = $this->fieldStorage->getName();
+    /** @var \Drupal\Core\Entity\RevisionableStorageInterface $storage */
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($this->entityTypeId);
+    $entity = $storage->loadRevision($revision_id);
+    foreach ($available_langcodes as $langcode => $value) {
+      $passed = $entity->getTranslation($langcode)->{$field_name}->value == $value + 1;
+      $this->assertTrue($passed, "The $langcode translation for revision {$entity->getRevisionId()} was correctly stored");
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/Views/FieldTestBase.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Views;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\node\Entity\NodeType;
+use Drupal\Tests\views\Functional\ViewTestBase;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Provides some helper methods for testing fieldapi integration into views.
+ *
+ * @todo Test on a generic entity not on a node. What has to be tested:
+ *   - Make sure that every wanted field is added to the according entity type.
+ *   - Make sure the joins are done correctly.
+ *   - Use basic fields and make sure that the full wanted object is built.
+ *   - Use relationships between different entity types, for example node and
+ *     the node author(user).
+ */
+abstract class FieldTestBase extends ViewTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['node', 'field_test_views'];
+
+  /**
+   * Stores the field definitions used by the test.
+   *
+   * @var array
+   */
+  public $fieldStorages;
+
+  /**
+   * Stores the fields of the field storage.
+   *
+   * @var array
+   */
+  public $fields;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp($import_test_views = TRUE, $modules = ['field_test_views']): void {
+    parent::setUp($import_test_views, $modules);
+
+    // Ensure the page node type exists.
+    NodeType::create([
+      'type' => 'page',
+      'name' => 'page',
+    ])->save();
+  }
+
+  public function setUpFieldStorages($amount = 3, $type = 'string') {
+    // Create three fields.
+    $field_names = [];
+    for ($i = 0; $i < $amount; $i++) {
+      $field_names[$i] = 'field_name_' . $i;
+      $this->fieldStorages[$i] = FieldStorageConfig::create([
+        'field_name' => $field_names[$i],
+        'entity_type' => 'node',
+        'type' => $type,
+      ]);
+      $this->fieldStorages[$i]->save();
+    }
+    return $field_names;
+  }
+
+  public function setUpFields($bundle = 'page') {
+    foreach ($this->fieldStorages as $key => $field_storage) {
+      $this->fields[$key] = FieldConfig::create([
+        'field_storage' => $field_storage,
+        'bundle' => $bundle,
+      ]);
+      $this->fields[$key]->save();
+    }
+  }
+
+}

core/modules/field/tests/src/Functional/Views/FieldUITest.php

@@ -0,0 +1,168 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Functional\Views;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\views\Views;
+
+/**
+ * Tests the UI of the field handler.
+ *
+ * @group field
+ * @see \Drupal\field\Plugin\views\field\Field
+ */
+class FieldUITest extends FieldTestBase {
+
+  /**
+   * Views used by this test.
+   *
+   * @var array
+   */
+  public static $testViews = ['test_view_fieldapi'];
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['views_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * A user with the 'administer views' permission.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $account;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp($import_test_views = TRUE, $modules = ['field_test_views']): void {
+    parent::setUp($import_test_views, $modules);
+
+    $this->account = $this->drupalCreateUser(['administer views']);
+    $this->drupalLogin($this->account);
+
+    $this->setUpFieldStorages(1, 'text');
+    $this->setUpFields();
+  }
+
+  /**
+   * Tests basic field handler settings in the UI.
+   */
+  public function testHandlerUI(): void {
+    $url = "admin/structure/views/nojs/handler/test_view_fieldapi/default/field/field_name_0";
+    $this->drupalGet($url);
+
+    // Tests the available formatter options.
+    $options = $this->assertSession()->selectExists('edit-options-type')->findAll('css', 'option');
+    $options = array_map(function ($item) {
+      return $item->getValue();
+    }, $options);
+    $this->assertEqualsCanonicalizing(['text_default', 'text_trimmed'], $options);
+
+    $this->submitForm(['options[type]' => 'text_trimmed'], 'Apply');
+
+    $this->drupalGet($url);
+    $this->assertTrue($this->assertSession()->optionExists('edit-options-type', 'text_trimmed')->isSelected());
+
+    $random_number = rand(100, 400);
+    $this->submitForm(['options[settings][trim_length]' => $random_number], 'Apply');
+    $this->drupalGet($url);
+    $this->assertSession()->fieldValueEquals('options[settings][trim_length]', $random_number);
+
+    // Save the view and test whether the settings are saved.
+    $this->drupalGet('admin/structure/views/view/test_view_fieldapi');
+    $this->submitForm([], 'Save');
+    $view = Views::getView('test_view_fieldapi');
+    $view->initHandlers();
+    $this->assertEquals('text_trimmed', $view->field['field_name_0']->options['type']);
+    $this->assertEquals($random_number, $view->field['field_name_0']->options['settings']['trim_length']);
+
+    // Now change the formatter back to 'default' which doesn't have any
+    // settings. We want to ensure that the settings are empty then.
+    $edit['options[type]'] = 'text_default';
+    $this->drupalGet('admin/structure/views/nojs/handler/test_view_fieldapi/default/field/field_name_0');
+    $this->submitForm($edit, 'Apply');
+    $this->drupalGet('admin/structure/views/view/test_view_fieldapi');
+    $this->submitForm([], 'Save');
+    $view = Views::getView('test_view_fieldapi');
+    $view->initHandlers();
+    $this->assertEquals('text_default', $view->field['field_name_0']->options['type']);
+    $this->assertEquals([], $view->field['field_name_0']->options['settings']);
+
+    // Ensure that the view depends on the field storage.
+    $dependencies = \Drupal::service('config.manager')->findConfigEntityDependencies('config', [$this->fieldStorages[0]->getConfigDependencyName()]);
+    $this->assertTrue(isset($dependencies['views.view.test_view_fieldapi']), 'The view is dependent on the field storage.');
+  }
+
+  /**
+   * Tests the basic field handler form when aggregation is enabled.
+   */
+  public function testHandlerUIAggregation(): void {
+    // Enable aggregation.
+    $edit = ['group_by' => '1'];
+    $this->drupalGet('admin/structure/views/nojs/display/test_view_fieldapi/default/group_by');
+    $this->submitForm($edit, 'Apply');
+
+    $url = "admin/structure/views/nojs/handler/test_view_fieldapi/default/field/field_name_0";
+    $this->drupalGet($url);
+    $this->assertSession()->statusCodeEquals(200);
+
+    // Test the click sort column options.
+    // Tests the available formatter options.
+    $options = $this->assertSession()->selectExists('edit-options-click-sort-column')->findAll('css', 'option');
+    $options = array_map(function ($item) {
+      return $item->getValue();
+    }, $options);
+    $this->assertEqualsCanonicalizing(['format', 'value'], $options);
+  }
+
+  /**
+   * Tests adding a boolean field filter handler.
+   */
+  public function testBooleanFilterHandler(): void {
+    // Create a boolean field.
+    $field_name = 'field_boolean';
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'node',
+      'type' => 'boolean',
+    ]);
+    $field_storage->save();
+    $field = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'page',
+    ]);
+    $field->save();
+
+    $url = "admin/structure/views/nojs/add-handler/test_view_fieldapi/default/filter";
+    $this->drupalGet($url);
+    $this->submitForm([
+      'name[node__' . $field_name . '.' . $field_name . '_value]' => TRUE,
+    ], 'Add and configure filter criteria');
+    $this->assertSession()->statusCodeEquals(200);
+    // Verify that using a boolean field as a filter also results in using the
+    // boolean plugin.
+    $this->assertSession()->elementTextEquals('xpath', '//label[@for="edit-options-value-1"]', 'True');
+    $this->assertSession()->elementTextEquals('xpath', '//label[@for="edit-options-value-0"]', 'False');
+
+    // Expose the filter and see if the 'Any' option is added and if we can save
+    // it.
+    $this->submitForm([], 'Expose filter');
+    $this->assertSession()->elementTextEquals('xpath', '//label[@for="edit-options-value-all"]', '- Any -');
+    $this->submitForm(['options[value]' => 'All', 'options[expose][required]' => FALSE], 'Apply');
+    $this->submitForm([], 'Save');
+    $this->drupalGet('/admin/structure/views/nojs/handler/test_view_fieldapi/default/filter/field_boolean_value');
+    $this->assertSession()->checkboxChecked('edit-options-value-all');
+  }
+
+}

core/modules/field/tests/src/FunctionalJavascript/Boolean/BooleanFormatterSettingsTest.php

@@ -0,0 +1,135 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\FunctionalJavascript\Boolean;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+
+/**
+ * Tests the Boolean field formatter settings.
+ *
+ * @group field
+ */
+class BooleanFormatterSettingsTest extends WebDriverTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of the entity bundle that is created in the test.
+   *
+   * @var string
+   */
+  protected $bundle;
+
+  /**
+   * The name of the Boolean field to use for testing.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a content type. Use Node because it has Field UI pages that work.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType(['name' => $type_name, 'type' => $type_name]);
+    $this->bundle = $type->id();
+
+    $admin_user = $this->drupalCreateUser([
+      'access content',
+      'administer content types',
+      'administer node fields',
+      'administer node display',
+      'bypass node access',
+      'administer nodes',
+    ]);
+    $this->drupalLogin($admin_user);
+
+    $this->fieldName = $this->randomMachineName(8);
+
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => 'node',
+      'type' => 'boolean',
+    ]);
+    $field_storage->save();
+
+    $instance = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => $this->bundle,
+      'label' => $this->randomMachineName(),
+    ]);
+    $instance->save();
+
+    $display = \Drupal::service('entity_display.repository')->getViewDisplay('node', $this->bundle)
+      ->setComponent($this->fieldName, [
+        'type' => 'boolean',
+        'settings' => [],
+      ]);
+    $display->save();
+  }
+
+  /**
+   * Tests the formatter settings page for the Boolean formatter.
+   */
+  public function testBooleanFormatterSettings(): void {
+    // List the options we expect to see on the settings form. Omit the one
+    // with the Unicode check/x characters, which does not appear to work
+    // well in BrowserTestBase.
+    $options = [
+      'Yes / No',
+      'True / False',
+      'On / Off',
+      'Enabled / Disabled',
+      '1 / 0',
+      'Custom',
+    ];
+
+    // For several different values of the field settings, test that the
+    // options, including default, are shown correctly.
+    $settings = [
+      ['Yes', 'No'],
+      ['On', 'Off'],
+      ['TRUE', 'FALSE'],
+    ];
+
+    $assert_session = $this->assertSession();
+    foreach ($settings as $values) {
+      // Set up the field settings.
+      $this->drupalGet('admin/structure/types/manage/' . $this->bundle . '/fields/node.' . $this->bundle . '.' . $this->fieldName);
+      $this->submitForm([
+        'settings[on_label]' => $values[0],
+        'settings[off_label]' => $values[1],
+      ], 'Save settings');
+
+      // Open the Manage Display page and trigger the field settings form.
+      $this->drupalGet('admin/structure/types/manage/' . $this->bundle . '/display');
+      $this->getSession()->getPage()->pressButton($this->fieldName . '_settings_edit');
+      $assert_session->waitForElement('css', '.ajax-new-content');
+
+      // Test that the settings options are present in the correct format.
+      foreach ($options as $string) {
+        $assert_session->pageTextContains($string);
+      }
+      $assert_session->pageTextContains("Field settings ({$values[0]} / {$values[1]})");
+    }
+  }
+
+}

core/modules/field/tests/src/FunctionalJavascript/EntityReference/EntityReferenceAdminTest.php

@@ -0,0 +1,367 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\FunctionalJavascript\EntityReference;
+
+use Behat\Mink\Element\NodeElement;
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Core\Url;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+use Drupal\Tests\field_ui\Traits\FieldUiJSTestTrait;
+use Drupal\Tests\field_ui\Traits\FieldUiTestTrait;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests for the administrative UI.
+ *
+ * @group entity_reference
+ */
+class EntityReferenceAdminTest extends WebDriverTestBase {
+
+  use FieldUiTestTrait;
+  use FieldUiJSTestTrait;
+
+  /**
+   * Modules to install.
+   *
+   * Enable path module to ensure that the selection handler does not fail for
+   * entities with a path field.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'node',
+    'field_ui',
+    'path',
+    'taxonomy',
+    'block',
+    'views_ui',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * The name of the content type created for testing purposes.
+   *
+   * @var string
+   */
+  protected $type;
+
+  /**
+   * Name of a second content type to be used as a target of entity references.
+   *
+   * @var string
+   */
+  protected $targetType;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+
+    // Create a content type, with underscores.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType(['name' => $type_name, 'type' => $type_name]);
+    $this->type = $type->id();
+
+    // Create a second content type, to be a target for entity reference fields.
+    $type_name = $this->randomMachineName(8) . '_test';
+    $type = $this->drupalCreateContentType(['name' => $type_name, 'type' => $type_name]);
+    $this->targetType = $type->id();
+
+    // Change the title field label.
+    $fields = \Drupal::service('entity_field.manager')
+      ->getFieldDefinitions('node', $type->id());
+    $fields['title']->getConfig($type->id())
+      ->setLabel($type->id() . ' title')->save();
+
+    // Add text field to the second content type.
+    FieldStorageConfig::create([
+      'field_name' => 'field_text',
+      'entity_type' => 'node',
+      'type' => 'text',
+      'entity_types' => ['node'],
+    ])->save();
+    FieldConfig::create([
+      'label' => 'Text Field',
+      'field_name' => 'field_text',
+      'entity_type' => 'node',
+      'bundle' => $this->targetType,
+      'settings' => [],
+      'required' => FALSE,
+    ])->save();
+
+    // Create test user.
+    $admin_user = $this->drupalCreateUser([
+      'access content',
+      'administer node fields',
+      'administer node display',
+      'administer views',
+      'create ' . $this->type . ' content',
+      'edit own ' . $this->type . ' content',
+    ]);
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests the Entity Reference Admin UI.
+   */
+  public function testFieldAdminHandler(): void {
+    $bundle_path = 'admin/structure/types/manage/' . $this->type;
+
+    $page = $this->getSession()->getPage();
+    /** @var \Drupal\FunctionalJavascriptTests\JSWebAssert $assert_session */
+    $assert_session = $this->assertSession();
+
+    // First step: 'Add new field' on the 'Manage fields' page.
+    $this->drupalGet($bundle_path . '/fields/add-field');
+
+    // Check if the commonly referenced entity types appear in the list.
+    $page->find('css', "[name='new_storage_type'][value='reference']")->getParent()->click();
+    $page->pressButton('Continue');
+    $assert_session->pageTextContains('Choose an option below');
+    $this->assertSession()->elementExists('css', "[name='group_field_options_wrapper'][value='field_ui:entity_reference:node']");
+    $this->assertSession()->elementExists('css', "[name='group_field_options_wrapper'][value='field_ui:entity_reference:user']");
+
+    $page->pressButton('Back');
+    $this->fieldUIAddNewFieldJS(NULL, 'test', 'Test', 'entity_reference', FALSE);
+
+    // Node should be selected by default.
+    $this->assertSession()->fieldValueEquals('field_storage[subform][settings][target_type]', 'node');
+
+    // Check that all entity types can be referenced.
+    $this->assertFieldSelectOptions('field_storage[subform][settings][target_type]', array_keys(\Drupal::entityTypeManager()->getDefinitions()));
+
+    // The base handler should be selected by default.
+    $this->assertSession()->fieldValueEquals('settings[handler]', 'default:node');
+
+    // The base handler settings should be displayed.
+    $entity_type_id = 'node';
+    // Check that the type label is correctly displayed.
+    $assert_session->pageTextContains('Content type');
+    // Check that sort options are not yet visible.
+    $sort_by = $page->findField('settings[handler_settings][sort][field]');
+    $this->assertNotEmpty($sort_by);
+    $this->assertFalse($sort_by->isVisible(), 'The "sort by" options are hidden.');
+    $bundles = $this->container->get('entity_type.bundle.info')->getBundleInfo($entity_type_id);
+    foreach ($bundles as $bundle_name => $bundle_info) {
+      $this->assertSession()->fieldExists('settings[handler_settings][target_bundles][' . $bundle_name . ']');
+    }
+
+    reset($bundles);
+
+    // Initially, no bundles are selected so no sort options are available.
+    $this->assertFieldSelectOptions('settings[handler_settings][sort][field]', ['_none']);
+
+    // Select this bundle so that standard sort options are available.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->type . ']')->setValue($this->type);
+    $assert_session->assertWaitOnAjaxRequest();
+    // Test that a non-translatable base field is a sort option.
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'nid');
+    // Test that a translatable base field is a sort option.
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'title');
+    // Test that a configurable field is a sort option.
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'body.value');
+    // Test that a field not on this bundle is not a sort option.
+    $assert_session->optionNotExists('settings[handler_settings][sort][field]', 'field_text.value');
+    // Test that the title option appears once, with the default label.
+    $title_options = $sort_by->findAll('xpath', 'option[@value="title"]');
+    $this->assertEquals(1, count($title_options));
+    $this->assertEquals('Title', $title_options[0]->getText());
+
+    // Also select the target bundle so that field_text is also available.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->targetType . ']')->setValue($this->targetType);
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'nid');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'title');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'body.value');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'field_text.value');
+
+    // Select only the target bundle. The options should be the same.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->type . ']')->uncheck();
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'nid');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'title');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'body.value');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'field_text.value');
+    // Exception: the title option has a different label.
+    $title_options = $sort_by->findAll('xpath', 'option[@value="title"]');
+    $this->assertEquals(1, count($title_options));
+    $this->assertEquals($this->targetType . ' title', $title_options[0]->getText());
+
+    // Test the sort settings.
+    // Option 0: no sort.
+    $this->assertSession()->fieldValueEquals('settings[handler_settings][sort][field]', '_none');
+    $sort_direction = $page->findField('settings[handler_settings][sort][direction]');
+    $this->assertFalse($sort_direction->isVisible());
+    // Option 1: sort by field.
+    $sort_by->setValue('nid');
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertTrue($sort_direction->isVisible());
+    $this->assertSession()->fieldValueEquals('settings[handler_settings][sort][direction]', 'ASC');
+
+    // Test that the sort-by options are sorted.
+    $labels = array_map(function (NodeElement $element) {
+      return $element->getText();
+    }, $sort_by->findAll('xpath', 'option'));
+    for ($i = count($labels) - 1, $sorted = TRUE; $i > 0; --$i) {
+      if ($labels[$i - 1] > $labels[$i]) {
+        $sorted = FALSE;
+        break;
+      }
+    }
+    $this->assertTrue($sorted, 'The "sort by" options are sorted.');
+
+    // Set back to no sort.
+    $sort_by->setValue('_none');
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertFalse($sort_direction->isVisible());
+
+    // Sort by nid, then select no bundles. The sort fields and sort direction
+    // should not display.
+    $sort_by->setValue('nid');
+    $assert_session->assertWaitOnAjaxRequest();
+    foreach ($bundles as $bundle_name => $bundle_info) {
+      $this->assertSession()->fieldExists('settings[handler_settings][target_bundles][' . $bundle_name . ']');
+      $checkbox = $page->findField('settings[handler_settings][target_bundles][' . $bundle_name . ']');
+      if ($checkbox->isChecked()) {
+        $checkbox->uncheck();
+        $assert_session->assertWaitOnAjaxRequest();
+      }
+    }
+    $this->assertFalse($sort_by->isVisible(), 'The "sort by" options are hidden.');
+    $this->assertFalse($sort_direction->isVisible());
+
+    // Select a bundle and check the same two fields.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->targetType . ']')->setValue($this->targetType);
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertTrue($sort_by->isVisible(), 'The "sort by" options are visible.');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'field_text.value');
+
+    // Un-select the bundle and check the same two fields.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->targetType . ']')->uncheck();
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertFalse($sort_by->isVisible(), 'The "sort by" options are hidden yet again.');
+    $this->assertFieldSelectOptions('settings[handler_settings][sort][field]', ['_none']);
+
+    // Third step: confirm.
+    $page->findField('settings[handler_settings][target_bundles][' . $this->targetType . ']')->setValue($this->targetType);
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->submitForm(['required' => '1'], 'Save settings');
+
+    // Check that the field appears in the overview form.
+    $this->assertSession()->elementTextContains('xpath', '//table[@id="field-overview"]//tr[@id="field-test"]/td[1]', "Test");
+
+    // Check that the field settings form can be submitted again, even when the
+    // field is required.
+    // The first 'Edit' link is for the Body field.
+    $this->clickLink('Edit', 1);
+    $this->submitForm([], 'Save settings');
+
+    // Switch the target type to 'taxonomy_term' and check that the settings
+    // specific to its selection handler are displayed.
+    $field_name = 'node.' . $this->type . '.field_test';
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $page->findField('field_storage[subform][settings][target_type]')->setValue('taxonomy_term');
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->assertSession()->fieldExists('settings[handler_settings][auto_create]');
+    $this->assertSession()->fieldValueEquals('settings[handler]', 'default:taxonomy_term');
+
+    // Switch the target type to 'user' and check that the settings specific to
+    // its selection handler are displayed.
+    $field_name = 'node.' . $this->type . '.field_test';
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $target_type_input = $assert_session->fieldExists('field_storage[subform][settings][target_type]');
+    $target_type_input->setValue('user');
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertSession()->fieldValueEquals('settings[handler_settings][filter][type]', '_none');
+    $this->assertSession()->fieldValueEquals('settings[handler_settings][sort][field]', '_none');
+    $assert_session->optionNotExists('settings[handler_settings][sort][field]', 'nid');
+    $assert_session->optionExists('settings[handler_settings][sort][field]', 'uid');
+
+    // Check that sort direction is visible only when a sort field is selected.
+    $sort_direction = $page->findField('settings[handler_settings][sort][direction]');
+    $this->assertFalse($sort_direction->isVisible());
+    $sort_by->setValue('name');
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertTrue($sort_direction->isVisible());
+
+    // Switch the target type to 'node'.
+    $field_name = 'node.' . $this->type . '.field_test';
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $page->findField('field_storage[subform][settings][target_type]')->setValue('node');
+
+    // Try to select the views handler.
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $page->findField('settings[handler]')->setValue('views');
+    $views_text = (string) new FormattableMarkup('No eligible views were found. <a href=":create">Create a view</a> with an <em>Entity Reference</em> display, or add such a display to an <a href=":existing">existing view</a>.', [
+      ':create' => Url::fromRoute('views_ui.add')->toString(),
+      ':existing' => Url::fromRoute('entity.view.collection')->toString(),
+    ]);
+    $assert_session->waitForElement('xpath', '//a[contains(text(), "Create a view")]');
+    $assert_session->responseContains($views_text);
+
+    $this->submitForm([], 'Save settings');
+    // If no eligible view is available we should see a message.
+    $assert_session->pageTextContains('The views entity selection mode requires a view.');
+
+    // Enable the entity_reference_test module which creates an eligible view.
+    $this->container->get('module_installer')
+      ->install(['entity_reference_test']);
+    $this->resetAll();
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $page->findField('settings[handler]')->setValue('views');
+    $assert_session
+      ->waitForField('settings[handler_settings][view][view_and_display]')
+      ->setValue('test_entity_reference:entity_reference_1');
+    $this->submitForm([], 'Save settings');
+    $assert_session->pageTextContains('Saved Test configuration.');
+
+    // Switch the target type to 'entity_test'.
+    $this->drupalGet($bundle_path . '/fields/' . $field_name);
+    $page->findField('field_storage[subform][settings][target_type]')->setValue('entity_test');
+    $assert_session->assertWaitOnAjaxRequest();
+    $page->findField('settings[handler]')->setValue('views');
+    $page
+      ->findField('settings[handler_settings][view][view_and_display]')
+      ->selectOption('test_entity_reference_entity_test:entity_reference_1');
+    $edit = [
+      'required' => FALSE,
+    ];
+    $this->submitForm($edit, 'Save settings');
+    $assert_session->pageTextContains('Saved Test configuration.');
+  }
+
+  /**
+   * Checks if a select element contains the specified options.
+   *
+   * @param string $name
+   *   The field name.
+   * @param array $expected_options
+   *   An array of expected options.
+   *
+   * @internal
+   */
+  protected function assertFieldSelectOptions(string $name, array $expected_options): void {
+    $field = $this->assertSession()->selectExists($name);
+    $options = $field->findAll('xpath', 'option');
+    $optgroups = $field->findAll('xpath', 'optgroup');
+    $nested_options = [];
+    foreach ($optgroups as $optgroup) {
+      $nested_options[] = $optgroup->findAll('xpath', 'option');
+    }
+    $options = array_merge($options, ...$nested_options);
+    array_walk($options, function (NodeElement &$option) {
+      $option = $option->getAttribute('value');
+    });
+    $this->assertEqualsCanonicalizing($expected_options, $options);
+  }
+
+}

core/modules/field/tests/src/FunctionalJavascript/MultipleValueWidgetTest.php

@@ -0,0 +1,213 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\FunctionalJavascript;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+
+/**
+ * Tests widget form for a multiple value field.
+ *
+ * @group field
+ */
+class MultipleValueWidgetTest extends WebDriverTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field_test', 'entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $account = $this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+    ]);
+    $this->drupalLogin($account);
+
+    $field = [
+      'field_name' => 'field_unlimited',
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $this->randomMachineName() . '_label',
+      'description' => '[site:name]_description',
+      'weight' => mt_rand(0, 127),
+      'settings' => [
+        'test_field_setting' => $this->randomMachineName(),
+      ],
+    ];
+
+    FieldStorageConfig::create([
+      'field_name' => 'field_unlimited',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED,
+    ])->save();
+    FieldConfig::create($field)->save();
+
+    $entity_form_display = EntityFormDisplay::load($field['entity_type'] . '.' . $field['bundle'] . '.default');
+    $entity_form_display->setComponent($field['field_name'])->save();
+  }
+
+  /**
+   * Tests the 'Add more' functionality.
+   */
+  public function testFieldMultipleValueWidget(): void {
+    $this->drupalGet('entity_test/add');
+
+    $assert_session = $this->assertSession();
+    $page = $this->getSession()->getPage();
+    $add_more_button = $page->findButton('field_unlimited_add_more');
+
+    // First set a value on the first input field.
+    $field_0 = $page->findField('field_unlimited[0][value]');
+    $field_0->setValue('1');
+
+    $field_0_remove_button = $page->findButton('field_unlimited_0_remove_button');
+    $this->assertNotEmpty($field_0_remove_button, 'First field has a remove button.');
+
+    // Add another item.
+    $add_more_button->click();
+    $field_1 = $assert_session->waitForField('field_unlimited[1][value]');
+    $this->assertNotEmpty($field_1, 'Successfully added another item.');
+
+    $field_1_remove_button = $page->findButton('field_unlimited_1_remove_button');
+    $this->assertNotEmpty($field_1_remove_button, 'Also second field has a remove button.');
+
+    // Validate the value of the first field has not changed.
+    $this->assertEquals('1', $field_0->getValue(), 'Value for the first item has not changed.');
+
+    // Validate the value of the second item is empty.
+    $this->assertEmpty($field_1->getValue(), 'Value for the second item is currently empty.');
+
+    // Add another item.
+    $add_more_button->click();
+    $field_2 = $assert_session->waitForField('field_unlimited[2][value]');
+    $this->assertNotEmpty($field_2, 'Successfully added another item.');
+
+    // Set values for the 2nd and 3rd fields to validate dragging.
+    $field_1->setValue('2');
+    $field_2->setValue('3');
+
+    $field_weight_0 = $page->findField('field_unlimited[0][_weight]');
+    $field_weight_1 = $page->findField('field_unlimited[1][_weight]');
+    $field_weight_2 = $page->findField('field_unlimited[2][_weight]');
+
+    // Assert starting situation matches expectations.
+    $this->assertGreaterThan($field_weight_0->getValue(), $field_weight_1->getValue());
+    $this->assertGreaterThan($field_weight_1->getValue(), $field_weight_2->getValue());
+
+    // Drag the first row after the third row.
+    $dragged = $field_0->find('xpath', 'ancestor::tr[contains(@class, "draggable")]//a[starts-with(@class, "tabledrag-handle")]');
+    $target = $field_2->find('xpath', 'ancestor::tr[contains(@class, "draggable")]');
+    $dragged->dragTo($target);
+
+    // Assert the order of items is updated correctly after dragging.
+    $this->assertGreaterThan($field_weight_2->getValue(), $field_weight_0->getValue());
+    $this->assertGreaterThan($field_weight_1->getValue(), $field_weight_2->getValue());
+
+    // Validate the order of items conforms to the last drag action after a
+    // updating the form via the server.
+    $add_more_button->click();
+    $field_3 = $assert_session->waitForField('field_unlimited[3][value]');
+    $this->assertNotEmpty($field_3);
+    $this->assertGreaterThan($field_weight_2->getValue(), $field_weight_0->getValue());
+    $this->assertGreaterThan($field_weight_1->getValue(), $field_weight_2->getValue());
+
+    // Validate no extraneous widget is displayed.
+    $element = $page->findField('field_unlimited[4][value]');
+    $this->assertEmpty($element);
+
+    // Test removing items/values.
+    $field_0_remove_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    // Test the updated widget.
+    // First item is the initial second item.
+    $this->assertEquals('2', $field_0->getValue(), 'Value for the first item has changed.');
+    // We do not have the initial first item anymore.
+    $this->assertEmpty($field_2->getValue(), 'Value for the third item is currently empty.');
+    $element = $page->findField('field_unlimited[3][value]');
+    $this->assertEmpty($element);
+
+    // We can also remove empty items.
+    $field_2_remove_button = $page->findButton('field_unlimited_2_remove_button');
+    $field_2_remove_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $element = $page->findField('field_unlimited[2][value]');
+    $this->assertEmpty($element, 'Empty field also removed.');
+
+    // Assert that the wrapper exists and isn't nested.
+    $this->assertSession()->elementsCount('css', '[data-drupal-selector="edit-field-unlimited-wrapper"]', 1);
+
+    // Test removing items/values on saved entities resets to initial value.
+    $this->submitForm([], 'Save');
+    $field_2_remove_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $field_1_remove_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $field_0_remove_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $add_more_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->assertSame('', $field_0->getValue());
+    $add_more_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->assertSame('', $field_1->getValue());
+  }
+
+  /**
+   * Tests that no validation occurs on field on "Add more" click.
+   */
+  public function testFieldMultipleValueWidgetAddMoreNoValidation(): void {
+    // Set unlimited field to be required.
+    $field_name = 'field_unlimited';
+    $field = FieldConfig::loadByName('entity_test', 'entity_test', $field_name);
+    $field->setRequired(TRUE);
+    $field->save();
+
+    $this->drupalGet('entity_test/add');
+    $assert_session = $this->assertSession();
+    $page = $this->getSession()->getPage();
+
+    // Add another item with the first item being empty, even though the field
+    // is required.
+    $add_more_button = $page->findButton('field_unlimited_add_more');
+    $add_more_button->click();
+    $field_1 = $assert_session->waitForField('field_unlimited[1][value]');
+    $this->assertNotEmpty($field_1, 'Successfully added another item.');
+    // Confirm the new item has focus.
+    $this->assertHasFocusByAttribute('name', 'field_unlimited[1][value]');
+    // The first item should not be in error state.
+    $assert_session->elementNotExists('css', 'input[name="field_unlimited[0][value]"].error');
+  }
+
+  /**
+   * Asserts an element specified by an attribute value has focus.
+   *
+   * @param string $name
+   *   The attribute name.
+   * @param string $value
+   *   The attribute value.
+   *
+   * @todo Replace with assertHasFocus() in https://drupal.org/i/3041768.
+   */
+  private function assertHasFocusByAttribute(string $name, string $value): void {
+    $active_element = $this->getSession()->evaluateScript('document.activeElement');
+    $this->assertSame($value, $active_element->attribute($name));
+  }
+
+}

core/modules/field/tests/src/FunctionalJavascript/Number/NumberFieldTest.php

@@ -0,0 +1,190 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\FunctionalJavascript\Number;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+use Drupal\node\Entity\Node;
+
+/**
+ * Tests the numeric field widget.
+ *
+ * @group field
+ */
+class NumberFieldTest extends WebDriverTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'administer content types',
+      'administer node fields',
+      'administer node display',
+      'bypass node access',
+      'administer entity_test fields',
+    ]));
+  }
+
+  /**
+   * Tests default formatter behavior.
+   */
+  public function testNumberFormatter(): void {
+    $type = $this->randomMachineName();
+    $float_field = $this->randomMachineName();
+    $integer_field = $this->randomMachineName();
+    $thousand_separators = ['', '.', ',', ' ', chr(8201), "'"];
+    $decimal_separators = ['.', ','];
+    $prefix = $this->randomMachineName();
+    $suffix = $this->randomMachineName();
+    $random_float = rand(0, pow(10, 6));
+    $random_integer = rand(0, pow(10, 6));
+    $assert_session = $this->assertSession();
+
+    // Create a content type containing float and integer fields.
+    $this->drupalCreateContentType(['type' => $type]);
+
+    FieldStorageConfig::create([
+      'field_name' => $float_field,
+      'entity_type' => 'node',
+      'type' => 'float',
+    ])->save();
+
+    FieldStorageConfig::create([
+      'field_name' => $integer_field,
+      'entity_type' => 'node',
+      'type' => 'integer',
+    ])->save();
+
+    FieldConfig::create([
+      'field_name' => $float_field,
+      'entity_type' => 'node',
+      'bundle' => $type,
+      'settings' => [
+        'prefix' => $prefix,
+        'suffix' => $suffix,
+      ],
+    ])->save();
+
+    FieldConfig::create([
+      'field_name' => $integer_field,
+      'entity_type' => 'node',
+      'bundle' => $type,
+      'settings' => [
+        'prefix' => $prefix,
+        'suffix' => $suffix,
+      ],
+    ])->save();
+
+    \Drupal::service('entity_display.repository')->getFormDisplay('node', $type, 'default')
+      ->setComponent($float_field, [
+        'type' => 'number',
+        'settings' => [
+          'placeholder' => '0.00',
+        ],
+      ])
+      ->setComponent($integer_field, [
+        'type' => 'number',
+        'settings' => [
+          'placeholder' => '0.00',
+        ],
+      ])
+      ->save();
+
+    \Drupal::service('entity_display.repository')->getViewDisplay('node', $type)
+      ->setComponent($float_field, [
+        'type' => 'number_decimal',
+      ])
+      ->setComponent($integer_field, [
+        'type' => 'number_unformatted',
+      ])
+      ->save();
+
+    // Create a node to test formatters.
+    $node = Node::create([
+      'type' => $type,
+      'title' => $this->randomMachineName(),
+      $float_field => ['value' => $random_float],
+      $integer_field => ['value' => $random_integer],
+    ]);
+    $node->save();
+
+    // Go to manage display page.
+    $this->drupalGet("admin/structure/types/manage/$type/display");
+
+    // Configure number_decimal formatter for the 'float' field type.
+    $thousand_separator = $thousand_separators[array_rand($thousand_separators)];
+    $decimal_separator = $decimal_separators[array_rand($decimal_separators)];
+    $scale = rand(0, 10);
+
+    $page = $this->getSession()->getPage();
+    $page->pressButton("{$float_field}_settings_edit");
+    $assert_session->waitForElement('css', '.ajax-new-content');
+    $edit = [
+      "fields[{$float_field}][settings_edit_form][settings][prefix_suffix]" => TRUE,
+      "fields[{$float_field}][settings_edit_form][settings][scale]" => $scale,
+      "fields[{$float_field}][settings_edit_form][settings][decimal_separator]" => $decimal_separator,
+      "fields[{$float_field}][settings_edit_form][settings][thousand_separator]" => $thousand_separator,
+    ];
+    foreach ($edit as $name => $value) {
+      $page->fillField($name, $value);
+    }
+    $page->pressButton("{$float_field}_plugin_settings_update");
+    $assert_session->waitForElement('css', '.field-plugin-summary-cell > .ajax-new-content');
+    $this->submitForm([], 'Save');
+
+    // Check number_decimal and number_unformatted formatters behavior.
+    $this->drupalGet('node/' . $node->id());
+    $float_formatted = number_format($random_float, $scale, $decimal_separator, $thousand_separator);
+    $this->assertSession()->responseContains("$prefix$float_formatted$suffix");
+    $this->assertSession()->responseContains((string) $random_integer);
+
+    // Configure the number_decimal formatter.
+    \Drupal::service('entity_display.repository')->getViewDisplay('node', $type)
+      ->setComponent($integer_field, [
+        'type' => 'number_integer',
+      ])
+      ->save();
+    $this->drupalGet("admin/structure/types/manage/$type/display");
+
+    $thousand_separator = $thousand_separators[array_rand($thousand_separators)];
+
+    $page = $this->getSession()->getPage();
+    $page->pressButton("{$integer_field}_settings_edit");
+    $assert_session->waitForElement('css', '.ajax-new-content');
+    $edit = [
+      "fields[{$integer_field}][settings_edit_form][settings][prefix_suffix]" => FALSE,
+      "fields[{$integer_field}][settings_edit_form][settings][thousand_separator]" => $thousand_separator,
+    ];
+    foreach ($edit as $name => $value) {
+      $page->fillField($name, $value);
+    }
+    $page->pressButton("{$integer_field}_plugin_settings_update");
+    $assert_session->waitForElement('css', '.field-plugin-summary-cell > .ajax-new-content');
+    $this->submitForm([], 'Save');
+
+    // Check number_integer formatter behavior.
+    $this->drupalGet('node/' . $node->id());
+
+    $integer_formatted = number_format($random_integer, 0, '', $thousand_separator);
+    $this->assertSession()->responseContains($integer_formatted);
+  }
+
+}

core/modules/field/tests/src/Kernel/AddToAllBundlesConfigActionTest.php

@@ -0,0 +1,148 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel;
+
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
+use Drupal\Core\Config\Action\ConfigActionException;
+use Drupal\Core\Entity\EntityFieldManagerInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Recipe\RecipeRunner;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\FunctionalTests\Core\Recipe\RecipeTestTrait;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\node\Entity\NodeType;
+
+/**
+ * @covers \Drupal\field\Plugin\ConfigAction\AddToAllBundles
+ *
+ * @group Recipe
+ * @group field
+ */
+class AddToAllBundlesConfigActionTest extends KernelTestBase {
+
+  use RecipeTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field', 'node', 'system', 'text', 'user'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    NodeType::create([
+      'type' => 'one',
+      'name' => 'One',
+    ])->save();
+    NodeType::create([
+      'type' => 'two',
+      'name' => 'Two',
+    ])->save();
+  }
+
+  /**
+   * Tests instantiating a field on all bundles of an entity type.
+   */
+  public function testInstantiateNewFieldOnAllBundles(): void {
+    // Ensure the body field doesn't actually exist yet.
+    $storage_definitions = $this->container->get(EntityFieldManagerInterface::class)
+      ->getFieldStorageDefinitions('node');
+    $this->assertArrayNotHasKey('body', $storage_definitions);
+
+    $this->applyAction('field.storage.node.body');
+
+    // Fields and expected data exist.
+    /** @var \Drupal\field\FieldConfigInterface[] $body_fields */
+    $body_fields = $this->container->get(EntityTypeManagerInterface::class)
+      ->getStorage('field_config')
+      ->loadByProperties([
+        'entity_type' => 'node',
+        'field_name' => 'body',
+      ]);
+    ksort($body_fields);
+    $this->assertSame(['node.one.body', 'node.two.body'], array_keys($body_fields));
+    foreach ($body_fields as $field) {
+      $this->assertSame('Body field label', $field->label());
+      $this->assertSame('Set by config actions.', $field->getDescription());
+    }
+
+    // Expect an error when the 'addToAllBundles' action is invoked on anything
+    // other than a field storage config entity.
+    $this->expectException(PluginNotFoundException::class);
+    $this->expectExceptionMessage('The "addToAllBundles" plugin does not exist.');
+    $this->applyAction('user.role.anonymous');
+  }
+
+  /**
+   * Tests that the action can be set to fail if the field already exists.
+   */
+  public function testFailIfExists(): void {
+    $this->installConfig('node');
+    node_add_body_field(NodeType::load('one'));
+
+    $this->expectException(ConfigActionException::class);
+    $this->expectExceptionMessage('Field node.one.body already exists.');
+    $this->applyAction('field.storage.node.body', TRUE);
+  }
+
+  /**
+   * Tests that the action will ignore existing fields by default.
+   */
+  public function testIgnoreExistingFields(): void {
+    $this->installConfig('node');
+
+    node_add_body_field(NodeType::load('one'))
+      ->setLabel('Original label')
+      ->setDescription('Original description')
+      ->save();
+
+    $this->applyAction('field.storage.node.body');
+
+    // The existing field should not be changed.
+    $field = FieldConfig::loadByName('node', 'one', 'body');
+    $this->assertInstanceOf(FieldConfig::class, $field);
+    $this->assertSame('Original label', $field->label());
+    $this->assertSame('Original description', $field->getDescription());
+
+    // But the new field should be created as expected.
+    $field = FieldConfig::loadByName('node', 'two', 'body');
+    $this->assertInstanceOf(FieldConfig::class, $field);
+    $this->assertSame('Body field label', $field->label());
+    $this->assertSame('Set by config actions.', $field->getDescription());
+  }
+
+  /**
+   * Applies a recipe with the addToAllBundles action.
+   *
+   * @param string $config_name
+   *   The name of the config object which should run the addToAllBundles
+   *   action.
+   * @param bool $fail_if_exists
+   *   (optional) Whether the action should fail if the field already exists on
+   *   any bundle. Defaults to FALSE.
+   */
+  private function applyAction(string $config_name, bool $fail_if_exists = FALSE): void {
+    $fail_if_exists = var_export($fail_if_exists, TRUE);
+    $contents = <<<YAML
+name: Instantiate field on all bundles
+config:
+  import:
+    node:
+      - field.storage.node.body
+  actions:
+    $config_name:
+      addToAllBundles:
+        label: Body field label
+        description: Set by config actions.
+        fail_if_exists: $fail_if_exists
+YAML;
+    $recipe = $this->createRecipe($contents);
+    RecipeRunner::processRecipe($recipe);
+  }
+
+}

core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php

@@ -0,0 +1,147 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Boolean;
+
+use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests the boolean formatter.
+ *
+ * @group field
+ */
+class BooleanFormatterTest extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = [
+    'field',
+    'text',
+    'entity_test',
+    'user',
+    'system',
+  ];
+
+  /**
+   * @var string
+   */
+  protected $entityType;
+
+  /**
+   * @var string
+   */
+  protected $bundle;
+
+  /**
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface
+   */
+  protected $display;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installConfig(['field']);
+    $this->installEntitySchema('entity_test');
+
+    $this->entityType = 'entity_test';
+    $this->bundle = $this->entityType;
+    $this->fieldName = $this->randomMachineName();
+
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => $this->entityType,
+      'type' => 'boolean',
+    ]);
+    $field_storage->save();
+
+    $instance = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => $this->bundle,
+      'label' => $this->randomMachineName(),
+    ]);
+    $instance->save();
+
+    $this->display = \Drupal::service('entity_display.repository')
+      ->getViewDisplay($this->entityType, $this->bundle)
+      ->setComponent($this->fieldName, [
+        'type' => 'boolean',
+        'settings' => [],
+      ]);
+    $this->display->save();
+  }
+
+  /**
+   * Renders fields of a given entity with a given display.
+   *
+   * @param \Drupal\Core\Entity\FieldableEntityInterface $entity
+   *   The entity object with attached fields to render.
+   * @param \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display
+   *   The display to render the fields in.
+   *
+   * @return string
+   *   The rendered entity fields.
+   */
+  protected function renderEntityFields(FieldableEntityInterface $entity, EntityViewDisplayInterface $display) {
+    $content = $display->build($entity);
+    $content = $this->render($content);
+    return $content;
+  }
+
+  /**
+   * Tests boolean formatter output.
+   */
+  public function testBooleanFormatter(): void {
+    $data = [];
+    $data[] = [0, [], 'Off'];
+    $data[] = [1, [], 'On'];
+
+    $format = ['format' => 'enabled-disabled'];
+    $data[] = [0, $format, 'Disabled'];
+    $data[] = [1, $format, 'Enabled'];
+
+    $format = ['format' => 'unicode-yes-no'];
+    $data[] = [1, $format, '✔'];
+    $data[] = [0, $format, '✖'];
+
+    $format = [
+      'format' => 'custom',
+      'format_custom_false' => 'FALSE',
+      'format_custom_true' => 'TRUE',
+    ];
+    $data[] = [0, $format, 'FALSE'];
+    $data[] = [1, $format, 'TRUE'];
+
+    foreach ($data as $test_data) {
+      [$value, $settings, $expected] = $test_data;
+
+      $component = $this->display->getComponent($this->fieldName);
+      $component['settings'] = $settings;
+      $this->display->setComponent($this->fieldName, $component);
+
+      $entity = EntityTest::create([]);
+      $entity->{$this->fieldName}->value = $value;
+
+      // Verify that all HTML is escaped and newlines are retained.
+      $this->renderEntityFields($entity, $this->display);
+      $this->assertRaw($expected);
+    }
+  }
+
+}

core/modules/field/tests/src/Kernel/Boolean/BooleanItemTest.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Boolean;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FieldItemInterface;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Tests\field\Kernel\FieldKernelTestBase;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests the new entity API for the boolean field type.
+ *
+ * @group field
+ */
+class BooleanItemTest extends FieldKernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a boolean field and storage for validation.
+    FieldStorageConfig::create([
+      'field_name' => 'field_boolean',
+      'entity_type' => 'entity_test',
+      'type' => 'boolean',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'field_name' => 'field_boolean',
+      'bundle' => 'entity_test',
+    ])->save();
+
+    // Create a form display for the default form mode.
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent('field_boolean', [
+        'type' => 'boolean_checkbox',
+      ])
+      ->save();
+  }
+
+  /**
+   * Tests using entity fields of the boolean field type.
+   */
+  public function testBooleanItem(): void {
+    // Verify entity creation.
+    $entity = EntityTest::create();
+    $value = '1';
+    $entity->field_boolean = $value;
+    $entity->name->value = $this->randomMachineName();
+    $entity->save();
+
+    // Verify entity has been created properly.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertInstanceOf(FieldItemListInterface::class, $entity->field_boolean);
+    $this->assertInstanceOf(FieldItemInterface::class, $entity->field_boolean[0]);
+    $this->assertEquals($value, $entity->field_boolean->value);
+    $this->assertEquals($value, $entity->field_boolean[0]->value);
+
+    // Verify changing the boolean value.
+    $new_value = 0;
+    $entity->field_boolean->value = $new_value;
+    $this->assertEquals($new_value, $entity->field_boolean->value);
+
+    // Read changed entity and assert changed values.
+    $entity->save();
+    $entity = EntityTest::load($id);
+    $this->assertEquals($new_value, $entity->field_boolean->value);
+
+    // Test sample item generation.
+    $entity = EntityTest::create();
+    $entity->field_boolean->generateSampleItems();
+    $this->entityValidateAndSave($entity);
+  }
+
+}

core/modules/field/tests/src/Kernel/BulkDeleteTest.php

@@ -0,0 +1,466 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel;
+
+use Drupal\Core\Database\Database;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Bulk delete storages and fields, and clean up afterwards.
+ *
+ * @group field
+ */
+class BulkDeleteTest extends FieldKernelTestBase {
+
+  /**
+   * The fields to use in this test.
+   *
+   * @var array
+   */
+  protected $fieldStorages;
+
+  /**
+   * The entities to use in this test.
+   *
+   * @var array
+   */
+  protected $entities;
+
+  /**
+   * The entities to use in this test, keyed by bundle.
+   *
+   * @var array
+   */
+  protected $entitiesByBundles;
+
+  /**
+   * The bundles for the entities used in this test.
+   *
+   * @var array
+   */
+  protected $bundles;
+
+  /**
+   * The entity type to be used in the test classes.
+   *
+   * @var string
+   */
+  protected $entityTypeId = 'entity_test';
+
+  /**
+   * Tests that the expected hooks have been invoked on the expected entities.
+   *
+   * @param $expected_hooks
+   *   An array keyed by hook name, with one entry per expected invocation.
+   *   Each entry is the value of the "$entity" parameter the hook is expected
+   *   to have been passed.
+   * @param $actual_hooks
+   *   The array of actual hook invocations recorded by field_test_memorize().
+   */
+  public function checkHooksInvocations($expected_hooks, $actual_hooks) {
+    foreach ($expected_hooks as $hook => $invocations) {
+      $actual_invocations = $actual_hooks[$hook];
+
+      // Check that the number of invocations is correct.
+      $this->assertSameSize($invocations, $actual_invocations, "$hook() was called the expected number of times.");
+
+      // Check that the hook was called for each expected argument.
+      foreach ($invocations as $argument) {
+        $found = FALSE;
+        foreach ($actual_invocations as $actual_arguments) {
+          // The argument we are looking for is either an array of entities as
+          // the second argument or a single entity object as the first.
+          if ($argument instanceof EntityInterface && $actual_arguments[0]->id() == $argument->id()) {
+            $found = TRUE;
+            break;
+          }
+          // In case of an array, compare the array size and make sure it
+          // contains the same elements.
+          elseif (is_array($argument) && count($actual_arguments[1]) == count($argument) && count(array_diff_key($actual_arguments[1], $argument)) == 0) {
+            $found = TRUE;
+            break;
+          }
+        }
+        $this->assertTrue($found, "$hook() was called on expected argument");
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->fieldStorages = [];
+    $this->entities = [];
+    $this->entitiesByBundles = [];
+
+    // Create two bundles.
+    $this->bundles = ['bb_1' => 'bb_1', 'bb_2' => 'bb_2'];
+    foreach ($this->bundles as $name => $desc) {
+      entity_test_create_bundle($name, $desc);
+    }
+
+    // Create two field storages.
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'bf_1',
+      'entity_type' => $this->entityTypeId,
+      'type' => 'test_field',
+      'cardinality' => 1,
+    ]);
+    $field_storage->save();
+    $this->fieldStorages[] = $field_storage;
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'bf_2',
+      'entity_type' => $this->entityTypeId,
+      'type' => 'test_field',
+      'cardinality' => 4,
+    ]);
+    $field_storage->save();
+    $this->fieldStorages[] = $field_storage;
+
+    // For each bundle, create each field, and 10 entities with values for the
+    // fields.
+    foreach ($this->bundles as $bundle) {
+      foreach ($this->fieldStorages as $field_storage) {
+        FieldConfig::create([
+          'field_storage' => $field_storage,
+          'bundle' => $bundle,
+        ])->save();
+      }
+      for ($i = 0; $i < 10; $i++) {
+        $entity = $this->container->get('entity_type.manager')
+          ->getStorage($this->entityTypeId)
+          ->create(['type' => $bundle]);
+        foreach ($this->fieldStorages as $field_storage) {
+          $entity->{$field_storage->getName()}->setValue($this->_generateTestFieldValues($field_storage->getCardinality()));
+        }
+        $entity->save();
+      }
+    }
+    $this->entities = $this->container->get('entity_type.manager')
+      ->getStorage($this->entityTypeId)->loadMultiple();
+    foreach ($this->entities as $entity) {
+      // This test relies on the entities having stale field definitions
+      // so that the deleted field can be accessed on them. Access the field
+      // now, so that they are always loaded.
+      $entity->bf_1->value;
+
+      // Also keep track of the entities per bundle.
+      $this->entitiesByBundles[$entity->bundle()][$entity->id()] = $entity;
+    }
+  }
+
+  /**
+   * Tests deleting fields.
+   *
+   * Verify that deleting a field leaves the field data items in the database
+   * and that the appropriate Field API functions can operate on the deleted
+   * data and field definition.
+   *
+   * This tests how EntityFieldQuery interacts with field deletion and could be
+   * moved to FieldCrudTestCase, but depends on this class's setUp().
+   */
+  public function testDeleteField(): void {
+    $bundle = reset($this->bundles);
+    $field_storage = reset($this->fieldStorages);
+    $field_name = $field_storage->getName();
+    $storage = \Drupal::entityTypeManager()->getStorage('entity_test');
+
+    // There are 10 entities of this bundle.
+    $found = $storage
+      ->getQuery()
+      ->accessCheck(FALSE)
+      ->condition('type', $bundle)
+      ->execute();
+    $this->assertCount(10, $found, 'Correct number of entities found before deleting');
+
+    // Delete the field.
+    $field = FieldConfig::loadByName($this->entityTypeId, $bundle, $field_name);
+    $field->delete();
+
+    // The field still exists, deleted.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['field_storage_uuid' => $field_storage->uuid(), 'deleted' => TRUE, 'include_deleted' => TRUE]);
+    $this->assertCount(1, $fields, 'There is one deleted field');
+    $field = $fields[$field->uuid()];
+    $this->assertEquals($bundle, $field->getTargetBundle(), 'The deleted field is for the correct bundle');
+
+    // Check that the actual stored content did not change during delete.
+    /** @var \Drupal\Core\Entity\Sql\DefaultTableMapping $table_mapping */
+    $table_mapping = $storage->getTableMapping();
+    $table = $table_mapping->getDedicatedDataTableName($field_storage);
+    $column = $table_mapping->getFieldColumnName($field_storage, 'value');
+    $result = Database::getConnection()->select($table, 't')
+      ->fields('t')
+      ->execute();
+    foreach ($result as $row) {
+      $this->assertEquals($row->{$column}, $this->entities[$row->entity_id]->{$field_name}->value);
+    }
+
+    // There are 0 entities of this bundle with non-deleted data.
+    $found = $storage
+      ->getQuery()
+      ->accessCheck(FALSE)
+      ->condition('type', $bundle)
+      ->condition("$field_name.deleted", 0)
+      ->execute();
+    $this->assertEmpty($found, 'No entities found after deleting');
+
+    // There are 10 entities of this bundle when deleted fields are allowed, and
+    // their values are correct.
+    $found = $storage
+      ->getQuery()
+      ->accessCheck(FALSE)
+      ->condition('type', $bundle)
+      ->condition("$field_name.deleted", 1)
+      ->sort('id')
+      ->execute();
+    $this->assertCount(10, $found, 'Correct number of entities found after deleting');
+    $this->assertEmpty(array_diff($found, array_keys($this->entities)));
+  }
+
+  /**
+   * Tests that recreating a field with the name as a deleted field works.
+   */
+  public function testPurgeWithDeletedAndActiveField(): void {
+    $bundle = reset($this->bundles);
+    // Create another field storage.
+    $field_name = 'bf_3';
+    $deleted_field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => $this->entityTypeId,
+      'type' => 'test_field',
+      'cardinality' => 1,
+    ]);
+    $deleted_field_storage->save();
+    // Create the field.
+    FieldConfig::create([
+      'field_storage' => $deleted_field_storage,
+      'bundle' => $bundle,
+    ])->save();
+
+    for ($i = 0; $i < 20; $i++) {
+      $entity = $this->container->get('entity_type.manager')
+        ->getStorage($this->entityTypeId)
+        ->create(['type' => $bundle]);
+      $entity->{$field_name}->setValue($this->_generateTestFieldValues(1));
+      $entity->save();
+    }
+
+    // Delete the field.
+    $deleted_field = FieldConfig::loadByName($this->entityTypeId, $bundle, $field_name);
+    $deleted_field->delete();
+    $deleted_field_uuid = $deleted_field->uuid();
+
+    // Reload the field storage.
+    $field_storages = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadByProperties(['uuid' => $deleted_field_storage->uuid(), 'include_deleted' => TRUE]);
+    $deleted_field_storage = reset($field_storages);
+
+    // Create the field again.
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => $this->entityTypeId,
+      'type' => 'test_field',
+      'cardinality' => 1,
+    ]);
+    $field_storage->save();
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => $bundle,
+    ])->save();
+
+    // The field still exists, deleted, with the same field name.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['uuid' => $deleted_field_uuid, 'include_deleted' => TRUE]);
+    $this->assertArrayHasKey($deleted_field_uuid, $fields);
+    $this->assertTrue($fields[$deleted_field_uuid]->isDeleted());
+    $this->assertSame($field_name, $fields[$deleted_field_uuid]->getName());
+
+    for ($i = 0; $i < 10; $i++) {
+      $entity = $this->container->get('entity_type.manager')
+        ->getStorage($this->entityTypeId)
+        ->create(['type' => $bundle]);
+      $entity->{$field_name}->setValue($this->_generateTestFieldValues(1));
+      $entity->save();
+    }
+
+    // Check that the two field storages have different tables.
+    $storage = \Drupal::entityTypeManager()->getStorage($this->entityTypeId);
+    /** @var \Drupal\Core\Entity\Sql\DefaultTableMapping $table_mapping */
+    $table_mapping = $storage->getTableMapping();
+    $deleted_table_name = $table_mapping->getDedicatedDataTableName($deleted_field_storage, TRUE);
+    $active_table_name = $table_mapping->getDedicatedDataTableName($field_storage);
+
+    field_purge_batch(50);
+
+    // Ensure the new field still has its table and the deleted one has been
+    // removed.
+    $this->assertTrue(\Drupal::database()->schema()->tableExists($active_table_name));
+    $this->assertFalse(\Drupal::database()->schema()->tableExists($deleted_table_name));
+
+    // The field has been removed from the system.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['field_storage_uuid' => $deleted_field_storage->uuid(), 'deleted' => TRUE, 'include_deleted' => TRUE]);
+    $this->assertCount(0, $fields, 'The field is gone');
+
+    // Verify there are still 10 entries in the main table.
+    $count = \Drupal::database()
+      ->select('entity_test__' . $field_name, 'f')
+      ->fields('f', ['entity_id'])
+      ->condition('bundle', $bundle)
+      ->countQuery()
+      ->execute()
+      ->fetchField();
+    $this->assertEquals(10, $count);
+  }
+
+  /**
+   * Tests purging fields.
+   *
+   * Verify that field data items and fields are purged when a field storage is
+   * deleted.
+   */
+  public function testPurgeField(): void {
+    // Start recording hook invocations.
+    field_test_memorize();
+
+    $bundle = reset($this->bundles);
+    $field_storage = reset($this->fieldStorages);
+    $field_name = $field_storage->getName();
+
+    // Delete the field.
+    $field = FieldConfig::loadByName($this->entityTypeId, $bundle, $field_name);
+    $field->delete();
+
+    // No field hooks were called.
+    $mem = field_test_memorize();
+    $this->assertCount(0, $mem, 'No field hooks were called');
+
+    $batch_size = 2;
+    for ($count = 8; $count >= 0; $count -= $batch_size) {
+      // Purge two entities.
+      field_purge_batch($batch_size);
+
+      // There are $count deleted entities left.
+      $found = \Drupal::entityQuery('entity_test')
+        ->accessCheck(FALSE)
+        ->condition('type', $bundle)
+        ->condition($field_name . '.deleted', 1)
+        ->execute();
+      $this->assertCount($count, $found, 'Correct number of entities found after purging 2');
+    }
+
+    // Check hooks invocations.
+    // FieldItemInterface::delete() should have been called once for each entity in the
+    // bundle.
+    $actual_hooks = field_test_memorize();
+    $hooks = [];
+    $hooks['field_test_field_delete'] = $this->entitiesByBundles[$bundle];
+    $this->checkHooksInvocations($hooks, $actual_hooks);
+
+    // The field still exists, deleted.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['field_storage_uuid' => $field_storage->uuid(), 'deleted' => TRUE, 'include_deleted' => TRUE]);
+    $this->assertCount(1, $fields, 'There is one deleted field');
+
+    // Purge the field.
+    field_purge_batch($batch_size);
+
+    // The field is gone.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['field_storage_uuid' => $field_storage->uuid(), 'deleted' => TRUE, 'include_deleted' => TRUE]);
+    $this->assertCount(0, $fields, 'The field is gone');
+
+    // The field storage still exists, not deleted, because it has a second
+    // field.
+    $storages = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadByProperties(['uuid' => $field_storage->uuid(), 'include_deleted' => TRUE]);
+    $this->assertTrue(isset($storages[$field_storage->uuid()]), 'The field storage exists and is not deleted');
+  }
+
+  /**
+   * Tests purging field storages.
+   *
+   * Verify that field storages are preserved and purged correctly as multiple
+   * fields are deleted and purged.
+   */
+  public function testPurgeFieldStorage(): void {
+    // Start recording hook invocations.
+    field_test_memorize();
+
+    $field_storage = reset($this->fieldStorages);
+    $field_name = $field_storage->getName();
+
+    // Delete the first field.
+    $bundle = reset($this->bundles);
+    $field = FieldConfig::loadByName($this->entityTypeId, $bundle, $field_name);
+    $field->delete();
+
+    // Assert that FieldItemInterface::delete() was not called yet.
+    $mem = field_test_memorize();
+    $this->assertCount(0, $mem, 'No field hooks were called.');
+
+    // Purge the data.
+    field_purge_batch(10);
+
+    // Check hooks invocations.
+    // FieldItemInterface::delete() should have been called once for each entity in the
+    // bundle.
+    $actual_hooks = field_test_memorize();
+    $hooks = [];
+    $hooks['field_test_field_delete'] = $this->entitiesByBundles[$bundle];
+    $this->checkHooksInvocations($hooks, $actual_hooks);
+
+    // The field still exists, deleted.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['uuid' => $field->uuid(), 'include_deleted' => TRUE]);
+    $this->assertArrayHasKey($field->uuid(), $fields);
+    $this->assertTrue($fields[$field->uuid()]->isDeleted());
+
+    // Purge again to purge the field.
+    field_purge_batch(0);
+
+    // The field is gone.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['uuid' => $field->uuid(), 'include_deleted' => TRUE]);
+    $this->assertCount(0, $fields, 'The field is purged.');
+    // The field storage still exists, not deleted.
+    $storages = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadByProperties(['uuid' => $field_storage->uuid(), 'include_deleted' => TRUE]);
+    $this->assertArrayHasKey($field_storage->uuid(), $storages);
+    $this->assertFalse($storages[$field_storage->uuid()]->isDeleted());
+
+    // Delete the second field.
+    $bundle = next($this->bundles);
+    $field = FieldConfig::loadByName($this->entityTypeId, $bundle, $field_name);
+    $field->delete();
+
+    // Assert that FieldItemInterface::delete() was not called yet.
+    $mem = field_test_memorize();
+    $this->assertCount(0, $mem, 'No field hooks were called.');
+
+    // Purge the data.
+    field_purge_batch(10);
+
+    // Check hooks invocations (same as above, for the 2nd bundle).
+    $actual_hooks = field_test_memorize();
+    $hooks = [];
+    $hooks['field_test_field_delete'] = $this->entitiesByBundles[$bundle];
+    $this->checkHooksInvocations($hooks, $actual_hooks);
+
+    // The field and the storage still exist, deleted.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['uuid' => $field->uuid(), 'include_deleted' => TRUE]);
+    $this->assertArrayHasKey($field->uuid(), $fields);
+    $this->assertTrue($fields[$field->uuid()]->isDeleted());
+    $storages = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadByProperties(['uuid' => $field_storage->uuid(), 'include_deleted' => TRUE]);
+    $this->assertArrayHasKey($field_storage->uuid(), $storages);
+    $this->assertTrue($storages[$field_storage->uuid()]->isDeleted());
+
+    // Purge again to purge the field and the storage.
+    field_purge_batch(0);
+
+    // The field and the storage are gone.
+    $fields = \Drupal::entityTypeManager()->getStorage('field_config')->loadByProperties(['uuid' => $field->uuid(), 'include_deleted' => TRUE]);
+    $this->assertCount(0, $fields, 'The field is purged.');
+    $storages = \Drupal::entityTypeManager()->getStorage('field_storage_config')->loadByProperties(['uuid' => $field_storage->uuid(), 'include_deleted' => TRUE]);
+    $this->assertCount(0, $storages, 'The field storage is purged.');
+  }
+
+}

core/modules/field/tests/src/Kernel/ConfigFieldDefinitionTest.php

@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel;
+
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+
+/**
+ * Tests exposing field definitions for configurable fields.
+ *
+ * @group field
+ */
+class ConfigFieldDefinitionTest extends FieldKernelTestBase {
+
+  /**
+   * @var string
+   */
+  private $entityType;
+
+  /**
+   * @var string
+   */
+  private $bundle;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a field and a storage of type 'test_field', on the 'entity_test'
+    // entity type.
+    $this->entityType = 'entity_test';
+    $this->bundle = 'entity_test';
+    $this->createFieldWithStorage('', $this->entityType, $this->bundle);
+
+    // Create a second field on 'entity_test_rev'.
+    $this->installEntitySchema('entity_test_rev');
+    $this->createFieldWithStorage('_rev', 'entity_test_rev', 'entity_test_rev');
+  }
+
+  /**
+   * Makes sure a field definition is exposed for a configurable field.
+   */
+  public function testBundleFieldDefinition(): void {
+    $definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions($this->entityType, $this->bundle);
+    $this->assertTrue(isset($definitions[$this->fieldTestData->field->getName()]));
+    $this->assertInstanceOf(FieldDefinitionInterface::class, $definitions[$this->fieldTestData->field->getName()]);
+    // Make sure fields on other entity types are not exposed.
+    $this->assertFalse(isset($definitions[$this->fieldTestData->field_rev->getName()]));
+  }
+
+  /**
+   * Makes sure a field storage definition is exposed for a configurable field.
+   */
+  public function testFieldStorageDefinition(): void {
+    $field_storage_definitions = \Drupal::service('entity_field.manager')->getFieldStorageDefinitions($this->entityType);
+    $this->assertTrue(isset($field_storage_definitions[$this->fieldTestData->field->getName()]));
+    $this->assertInstanceOf(FieldStorageDefinitionInterface::class, $field_storage_definitions[$this->fieldTestData->field->getName()]);
+    // Make sure storages on other entity types are not exposed.
+    $this->assertFalse(isset($field_storage_definitions[$this->fieldTestData->field_rev->getName()]));
+  }
+
+}

core/modules/field/tests/src/Kernel/DisplayApiTest.php

@@ -0,0 +1,325 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Core\Entity\Entity\EntityViewMode;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests the field display API.
+ *
+ * @group field
+ */
+class DisplayApiTest extends FieldKernelTestBase {
+
+  /**
+   * The field name to use in this test.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * The field label to use in this test.
+   *
+   * @var string
+   */
+  protected $label;
+
+  /**
+   * The field cardinality to use in this test.
+   *
+   * @var int
+   */
+  protected $cardinality;
+
+  /**
+   * The field display options to use in this test.
+   *
+   * @var array
+   */
+  protected $displayOptions;
+
+  /**
+   * The test entity.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface
+   */
+  protected $entity;
+
+  /**
+   * An array of random values, in the format expected for field values.
+   *
+   * @var array
+   */
+  protected $values;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['system'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a field and its storage.
+    $this->fieldName = 'test_field';
+    $this->label = $this->randomMachineName();
+    $this->cardinality = 4;
+
+    $field_storage = [
+      'field_name' => $this->fieldName,
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => $this->cardinality,
+    ];
+    $field = [
+      'field_name' => $this->fieldName,
+      'entity_type' => 'entity_test',
+      'bundle' => 'entity_test',
+      'label' => $this->label,
+    ];
+
+    $this->displayOptions = [
+      'default' => [
+        'type' => 'field_test_default',
+        'settings' => [
+          'test_formatter_setting' => $this->randomMachineName(),
+        ],
+      ],
+      'teaser' => [
+        'type' => 'field_test_default',
+        'settings' => [
+          'test_formatter_setting' => $this->randomMachineName(),
+        ],
+      ],
+    ];
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    FieldStorageConfig::create($field_storage)->save();
+    FieldConfig::create($field)->save();
+    // Create a display for the default view mode.
+    $display_repository->getViewDisplay($field['entity_type'], $field['bundle'])
+      ->setComponent($this->fieldName, $this->displayOptions['default'])
+      ->save();
+    // Create a display for the teaser view mode.
+    EntityViewMode::create([
+      'id' => 'entity_test.teaser',
+      'label' => 'Teaser',
+      'targetEntityType' => 'entity_test',
+    ])->save();
+    $display_repository->getViewDisplay($field['entity_type'], $field['bundle'], 'teaser')
+      ->setComponent($this->fieldName, $this->displayOptions['teaser'])
+      ->save();
+
+    // Create an entity with values.
+    $this->values = $this->_generateTestFieldValues($this->cardinality);
+    $this->entity = EntityTest::create();
+    $this->entity->{$this->fieldName}->setValue($this->values);
+    $this->entity->save();
+  }
+
+  /**
+   * Tests the FieldItemListInterface::view() method.
+   */
+  public function testFieldItemListView(): void {
+    $items = $this->entity->get($this->fieldName);
+
+    \Drupal::service('theme_installer')->install(['stark']);
+    $this->config('system.theme')->set('default', 'stark')->save();
+
+    // No display settings: check that default display settings are used.
+    $build = $items->view();
+    $this->render($build);
+    $settings = \Drupal::service('plugin.manager.field.formatter')->getDefaultSettings('field_test_default');
+    $setting = $settings['test_formatter_setting'];
+    $this->assertText($this->label, 'Label was displayed.');
+    foreach ($this->values as $delta => $value) {
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // Display settings: Check hidden field.
+    $display = [
+      'label' => 'hidden',
+      'type' => 'field_test_multiple',
+      'settings' => [
+        'test_formatter_setting_multiple' => $this->randomMachineName(),
+        'alter' => TRUE,
+      ],
+    ];
+    $build = $items->view($display);
+    $this->render($build);
+    $setting = $display['settings']['test_formatter_setting_multiple'];
+    $this->assertNoText($this->label, 'Label was not displayed.');
+    $this->assertText('field_test_entity_display_build_alter', 'Alter fired, display passed.');
+    $this->assertText('entity language is en', 'Language is placed onto the context.');
+    $array = [];
+    foreach ($this->values as $delta => $value) {
+      $array[] = $delta . ':' . $value['value'];
+    }
+    $this->assertText($setting . '|' . implode('|', $array), 'Values were displayed with expected setting.');
+
+    // Display settings: Check visually_hidden field.
+    $display = [
+      'label' => 'visually_hidden',
+      'type' => 'field_test_multiple',
+      'settings' => [
+        'test_formatter_setting_multiple' => $this->randomMachineName(),
+        'alter' => TRUE,
+      ],
+    ];
+    $build = $items->view($display);
+    $this->render($build);
+    $setting = $display['settings']['test_formatter_setting_multiple'];
+    $this->assertRaw('visually-hidden', 'Label was visually hidden.');
+    $this->assertText('field_test_entity_display_build_alter', 'Alter fired, display passed.');
+    $this->assertText('entity language is en', 'Language is placed onto the context.');
+    $array = [];
+    foreach ($this->values as $delta => $value) {
+      $array[] = $delta . ':' . $value['value'];
+    }
+    $this->assertText($setting . '|' . implode('|', $array), 'Values were displayed with expected setting.');
+
+    // Check the prepare_view steps are invoked.
+    $display = [
+      'label' => 'hidden',
+      'type' => 'field_test_with_prepare_view',
+      'settings' => [
+        'test_formatter_setting_additional' => $this->randomMachineName(),
+      ],
+    ];
+    $build = $items->view($display);
+    $this->render($build);
+    $setting = $display['settings']['test_formatter_setting_additional'];
+    $this->assertNoText($this->label, 'Label was not displayed.');
+    $this->assertNoText('field_test_entity_display_build_alter', 'Alter not fired.');
+    foreach ($this->values as $delta => $value) {
+      $this->assertText($setting . '|' . $value['value'] . '|' . ($value['value'] + 1), new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // View mode: check that display settings specified in the display object
+    // are used.
+    $build = $items->view('teaser');
+    $this->render($build);
+    $setting = $this->displayOptions['teaser']['settings']['test_formatter_setting'];
+    $this->assertText($this->label, 'Label was displayed.');
+    foreach ($this->values as $delta => $value) {
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // Unknown view mode: check that display settings for 'default' view mode
+    // are used.
+    $build = $items->view('unknown_view_mode');
+    $this->render($build);
+    $setting = $this->displayOptions['default']['settings']['test_formatter_setting'];
+    $this->assertText($this->label, 'Label was displayed.');
+    foreach ($this->values as $delta => $value) {
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+  }
+
+  /**
+   * Tests the FieldItemInterface::view() method.
+   */
+  public function testFieldItemView(): void {
+    // No display settings: check that default display settings are used.
+    $settings = \Drupal::service('plugin.manager.field.formatter')->getDefaultSettings('field_test_default');
+    $setting = $settings['test_formatter_setting'];
+    foreach ($this->values as $delta => $value) {
+      $item = $this->entity->{$this->fieldName}[$delta];
+      $build = $item->view();
+      $this->render($build);
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // Check that explicit display settings are used.
+    $display = [
+      'type' => 'field_test_multiple',
+      'settings' => [
+        'test_formatter_setting_multiple' => $this->randomMachineName(),
+      ],
+    ];
+    $setting = $display['settings']['test_formatter_setting_multiple'];
+    foreach ($this->values as $delta => $value) {
+      $item = $this->entity->{$this->fieldName}[$delta];
+      $build = $item->view($display);
+      $this->render($build);
+      $this->assertText($setting . '|0:' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // Check that prepare_view steps are invoked.
+    $display = [
+      'type' => 'field_test_with_prepare_view',
+      'settings' => [
+        'test_formatter_setting_additional' => $this->randomMachineName(),
+      ],
+    ];
+    $setting = $display['settings']['test_formatter_setting_additional'];
+    foreach ($this->values as $delta => $value) {
+      $item = $this->entity->{$this->fieldName}[$delta];
+      $build = $item->view($display);
+      $this->render($build);
+      $this->assertText($setting . '|' . $value['value'] . '|' . ($value['value'] + 1), new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // View mode: check that display settings specified in the field are used.
+    $setting = $this->displayOptions['teaser']['settings']['test_formatter_setting'];
+    foreach ($this->values as $delta => $value) {
+      $item = $this->entity->{$this->fieldName}[$delta];
+      $build = $item->view('teaser');
+      $this->render($build);
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+
+    // Unknown view mode: check that display settings for 'default' view mode
+    // are used.
+    $setting = $this->displayOptions['default']['settings']['test_formatter_setting'];
+    foreach ($this->values as $delta => $value) {
+      $item = $this->entity->{$this->fieldName}[$delta];
+      $build = $item->view('unknown_view_mode');
+      $this->render($build);
+      $this->assertText($setting . '|' . $value['value'], new FormattableMarkup('Value @delta was displayed with expected setting.', ['@delta' => $delta]));
+    }
+  }
+
+  /**
+   * Tests that the prepareView() formatter method still fires for empty values.
+   */
+  public function testFieldEmpty(): void {
+    // Uses \Drupal\field_test\Plugin\Field\FieldFormatter\TestFieldEmptyFormatter.
+    $display = [
+      'label' => 'hidden',
+      'type' => 'field_empty_test',
+      'settings' => [
+        'test_empty_string' => '**EMPTY FIELD**' . $this->randomMachineName(),
+      ],
+    ];
+    // $this->entity is set by the setUp() method and by default contains 4
+    // numeric values.  We only want to test the display of this one field.
+    $build = $this->entity->get($this->fieldName)->view($display);
+    $this->render($build);
+    // The test field by default contains values, so should not display the
+    // default "empty" text.
+    $this->assertNoText($display['settings']['test_empty_string']);
+
+    // Now remove the values from the test field and retest.
+    $this->entity->{$this->fieldName} = [];
+    $this->entity->save();
+    $build = $this->entity->get($this->fieldName)->view($display);
+    $this->render($build);
+    // This time, as the field values have been removed, we *should* show the
+    // default "empty" text.
+    $this->assertText($display['settings']['test_empty_string']);
+  }
+
+}

core/modules/field/tests/src/Kernel/DisplayModeUpdateTest.php

@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel;
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Entity\Entity\EntityFormMode;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\Core\Entity\Entity\EntityViewMode;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Ensure display modes are updated when fields are created.
+ *
+ * @group field
+ */
+class DisplayModeUpdateTest extends FieldKernelTestBase {
+
+  /**
+   * The default view display name.
+   *
+   * @var string
+   */
+  protected $defaultViewDisplayName;
+
+  /**
+   * The default form display name.
+   *
+   * @var string
+   */
+  protected $defaultFormDisplayName;
+
+  /**
+   * The alternate view display name.
+   *
+   * @var string
+   */
+  protected $foobarViewDisplayName;
+
+  /**
+   * The alternate form display name.
+   *
+   * @var string
+   */
+  protected $foobarFormDisplayName;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create 'default' view-display.
+    $default_view_display = EntityViewDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'default',
+      'status' => TRUE,
+    ]);
+    $default_view_display->save();
+    $this->defaultViewDisplayName = $default_view_display->getConfigDependencyName();
+
+    // Create 'default' form-display.
+    $default_form_display = EntityFormDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'default',
+      'status' => TRUE,
+    ]);
+    $default_form_display->save();
+    $this->defaultFormDisplayName = $default_form_display->getConfigDependencyName();
+
+    // Create a view-mode 'foobar', create view-display that uses it.
+    EntityViewMode::create([
+      'id' => 'entity_test.foobar',
+      'label' => 'Foobar',
+      'targetEntityType' => 'entity_test',
+      'status' => TRUE,
+      'enabled' => TRUE,
+    ])->save();
+    $foobar_view_display = EntityViewDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'foobar',
+      'status' => TRUE,
+    ]);
+    $foobar_view_display->save();
+    $this->foobarViewDisplayName = $foobar_view_display->getConfigDependencyName();
+
+    // Create a new form-mode 'foobar', create form-display that uses it.
+    EntityFormMode::create([
+      'id' => 'entity_test.foobar',
+      'label' => 'Foobar',
+      'targetEntityType' => 'entity_test',
+      'status' => TRUE,
+      'enabled' => TRUE,
+    ])->save();
+    $foobar_form_display = EntityFormDisplay::create([
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'foobar',
+      'status' => TRUE,
+    ]);
+    $foobar_form_display->save();
+    $this->foobarFormDisplayName = $foobar_form_display->getConfigDependencyName();
+  }
+
+  /**
+   * Ensure display modes are updated when fields are created.
+   */
+  public function testDisplayModeUpdateAfterFieldCreation(): void {
+
+    // Sanity test: field has not been created yet, so should not exist in display.
+    $this->assertArrayNotHasKey('field_test', \Drupal::config($this->defaultViewDisplayName)->get('hidden'));
+    $this->assertArrayNotHasKey('field_test', \Drupal::config($this->defaultFormDisplayName)->get('hidden'));
+    $this->assertArrayNotHasKey('field_test', \Drupal::config($this->foobarViewDisplayName)->get('hidden'));
+    $this->assertArrayNotHasKey('field_test', \Drupal::config($this->foobarFormDisplayName)->get('hidden'));
+
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'field_test',
+      'entity_type' => 'entity_test',
+      'type' => 'test_field',
+      'cardinality' => 1,
+    ]);
+    $field_storage->save();
+
+    FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test',
+    ])->save();
+
+    // Ensure field is added to display modes.
+    $this->assertArrayHasKey('field_test', \Drupal::config($this->defaultViewDisplayName)->get('hidden'));
+    $this->assertArrayHasKey('field_test', \Drupal::config($this->defaultFormDisplayName)->get('hidden'));
+    $this->assertArrayHasKey('field_test', \Drupal::config($this->foobarViewDisplayName)->get('hidden'));
+    $this->assertArrayHasKey('field_test', \Drupal::config($this->foobarFormDisplayName)->get('hidden'));
+
+  }
+
+}

core/modules/field/tests/src/Kernel/Email/EmailItemTest.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Email;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FieldItemInterface;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Tests\field\Kernel\FieldKernelTestBase;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests the new entity API for the email field type.
+ *
+ * @group field
+ */
+class EmailItemTest extends FieldKernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create an email field storage and field for validation.
+    FieldStorageConfig::create([
+      'field_name' => 'field_email',
+      'entity_type' => 'entity_test',
+      'type' => 'email',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'field_name' => 'field_email',
+      'bundle' => 'entity_test',
+    ])->save();
+
+    // Create a form display for the default form mode.
+    \Drupal::service('entity_display.repository')
+      ->getFormDisplay('entity_test', 'entity_test')
+      ->setComponent('field_email', [
+        'type' => 'email_default',
+      ])
+      ->save();
+  }
+
+  /**
+   * Tests using entity fields of the email field type.
+   */
+  public function testEmailItem(): void {
+    // Verify entity creation.
+    $entity = EntityTest::create();
+    $value = 'test@example.com';
+    $entity->field_email = $value;
+    $entity->name->value = $this->randomMachineName();
+    $entity->save();
+
+    // Verify entity has been created properly.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertInstanceOf(FieldItemListInterface::class, $entity->field_email);
+    $this->assertInstanceOf(FieldItemInterface::class, $entity->field_email[0]);
+    $this->assertEquals($value, $entity->field_email->value);
+    $this->assertEquals($value, $entity->field_email[0]->value);
+
+    // Verify changing the email value.
+    $new_value = $this->randomMachineName();
+    $entity->field_email->value = $new_value;
+    $this->assertEquals($new_value, $entity->field_email->value);
+
+    // Read changed entity and assert changed values.
+    $entity->save();
+    $entity = EntityTest::load($id);
+    $this->assertEquals($new_value, $entity->field_email->value);
+
+    // Test sample item generation.
+    $entity = EntityTest::create();
+    $entity->field_email->generateSampleItems();
+    $this->entityValidateAndSave($entity);
+  }
+
+}

core/modules/field/tests/src/Kernel/Entity/FieldConfigValidationTest.php

@@ -0,0 +1,191 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Entity;
+
+use Drupal\entity_test\Entity\EntityTestBundle;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\Core\Config\ConfigEntityValidationTestBase;
+use Drupal\Tests\node\Traits\ContentTypeCreationTrait;
+
+/**
+ * Tests validation of field_config entities.
+ *
+ * @group field
+ * @group #slow
+ */
+class FieldConfigValidationTest extends ConfigEntityValidationTestBase {
+
+  use ContentTypeCreationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field', 'node', 'entity_test', 'text', 'user'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installConfig('node');
+    $this->createContentType(['type' => 'one']);
+    $this->createContentType(['type' => 'another']);
+
+    EntityTestBundle::create(['id' => 'one'])->save();
+    EntityTestBundle::create(['id' => 'another'])->save();
+
+    $this->entity = FieldConfig::loadByName('node', 'one', 'body');
+  }
+
+  /**
+   * Tests that validation fails if config dependencies are invalid.
+   */
+  public function testInvalidDependencies(): void {
+    // Remove the config dependencies from the field entity.
+    $dependencies = $this->entity->getDependencies();
+    $dependencies['config'] = [];
+    $this->entity->set('dependencies', $dependencies);
+
+    $this->assertValidationErrors(['' => 'This field requires a field storage.']);
+
+    // Things look sort-of like `field.storage.*.*` should fail validation
+    // because they don't exist.
+    $dependencies['config'] = [
+      'field.storage.fake',
+      'field.storage.',
+      'field.storage.user.',
+    ];
+    $this->entity->set('dependencies', $dependencies);
+    $this->assertValidationErrors([
+      'dependencies.config.0' => "The 'field.storage.fake' config does not exist.",
+      'dependencies.config.1' => "The 'field.storage.' config does not exist.",
+      'dependencies.config.2' => "The 'field.storage.user.' config does not exist.",
+    ]);
+  }
+
+  /**
+   * Tests validation of a field_config's default value.
+   */
+  public function testMultilineTextFieldDefaultValue(): void {
+    // First, create a field storage for which a complex default value exists.
+    $this->enableModules(['text']);
+    $text_field_storage_config = FieldStorageConfig::create([
+      'type' => 'text_with_summary',
+      'field_name' => 'novel',
+      'entity_type' => 'user',
+    ]);
+    $text_field_storage_config->save();
+
+    $this->entity = FieldConfig::create([
+      'field_storage' => $text_field_storage_config,
+      'bundle' => 'user',
+      'default_value' => [
+        0 => [
+          'value' => "Multi\nLine",
+          'summary' => '',
+          'format' => 'basic_html',
+        ],
+      ],
+      'dependencies' => [
+        'config' => [
+          $text_field_storage_config->getConfigDependencyName(),
+        ],
+      ],
+    ]);
+    $this->assertValidationErrors([]);
+  }
+
+  /**
+   * Tests that the target bundle of the field is checked.
+   */
+  public function testTargetBundleMustExist(): void {
+    $this->entity->set('bundle', 'nope');
+    $this->assertValidationErrors([
+      '' => "The 'bundle' property cannot be changed.",
+      'bundle' => "The 'nope' bundle does not exist on the 'node' entity type.",
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testImmutableProperties(array $valid_values = []): void {
+    // If we don't clear the previous settings here, we will get unrelated
+    // validation errors (in addition to the one we're expecting), because the
+    // settings from the *old* field_type won't match the config schema for the
+    // settings of the *new* field_type.
+    $this->entity->set('settings', []);
+    parent::testImmutableProperties([
+      'entity_type' => 'entity_test_with_bundle',
+      'bundle' => 'another',
+      'field_type' => 'string',
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testRequiredPropertyKeysMissing(?array $additional_expected_validation_errors_when_missing = NULL): void {
+    parent::testRequiredPropertyKeysMissing([
+      'dependencies' => [
+        // @see ::testInvalidDependencies()
+        // @see \Drupal\Core\Config\Plugin\Validation\Constraint\RequiredConfigDependenciesConstraintValidator
+        '' => 'This field requires a field storage.',
+      ],
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testRequiredPropertyValuesMissing(?array $additional_expected_validation_errors_when_missing = NULL): void {
+    parent::testRequiredPropertyValuesMissing([
+      'dependencies' => [
+        // @see ::testInvalidDependencies()
+        // @see \Drupal\Core\Config\Plugin\Validation\Constraint\RequiredConfigDependenciesConstraintValidator
+        '' => 'This field requires a field storage.',
+      ],
+    ]);
+  }
+
+  /**
+   * Tests that the field type plugin's existence is validated.
+   */
+  public function testFieldTypePluginIsValidated(): void {
+    // The `field_type` property is immutable, so we need to clone the entity in
+    // order to cleanly change its immutable properties.
+    $this->entity = $this->entity->createDuplicate()
+      // We need to clear the current settings, or we will get validation errors
+      // because the old settings are not supported by the new field type.
+      ->set('settings', [])
+      ->set('field_type', 'invalid');
+
+    $this->assertValidationErrors([
+      'field_type' => "The 'invalid' plugin does not exist.",
+    ]);
+  }
+
+  /**
+   * Tests that entity reference selection handler plugin IDs are validated.
+   */
+  public function testEntityReferenceSelectionHandlerIsValidated(): void {
+    $this->container->get('state')
+      ->set('field_test_disable_broken_entity_reference_handler', TRUE);
+    $this->enableModules(['field_test']);
+
+    // The `field_type` property is immutable, so we need to clone the entity in
+    // order to cleanly change its immutable properties.
+    $this->entity = $this->entity->createDuplicate()
+      ->set('field_type', 'entity_reference')
+      ->set('settings', ['handler' => 'non_existent']);
+
+    $this->assertValidationErrors([
+      'settings.handler' => "The 'non_existent' plugin does not exist.",
+    ]);
+  }
+
+}

core/modules/field/tests/src/Kernel/Entity/FieldEntitySettingsTest.php

@@ -0,0 +1,120 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Entity;
+
+use Drupal\entity_test\Entity\EntityTestBundle;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests the ways that field entities handle their settings.
+ *
+ * @group field
+ */
+class FieldEntitySettingsTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['entity_test', 'field'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    EntityTestBundle::create(['id' => 'test', 'label' => 'Test'])->save();
+  }
+
+  /**
+   * @group legacy
+   */
+  public function testFieldEntitiesCarryDefaultSettings(): void {
+    /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
+    $field_storage = FieldStorageConfig::create([
+      'type' => 'integer',
+      'entity_type' => 'entity_test_with_bundle',
+      'field_name' => 'test',
+    ]);
+    $field = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'test',
+    ]);
+
+    /** @var \Drupal\Core\Field\FieldTypePluginManagerInterface $plugin_manager */
+    $plugin_manager = $this->container->get('plugin.manager.field.field_type');
+    $default_storage_settings = $plugin_manager->getDefaultStorageSettings('integer');
+    $default_field_settings = $plugin_manager->getDefaultFieldSettings('integer');
+
+    // Both entities should have the complete, default settings for their
+    // field type.
+    $this->assertSame($default_storage_settings, $field_storage->get('settings'));
+    $this->assertSame($default_field_settings, $field->get('settings'));
+
+    // If we try to set incomplete settings, the existing values should be
+    // retained.
+    $storage_settings = $field_storage->setSettings(['size' => 'big'])
+      ->get('settings');
+    // There should be no missing settings.
+    $missing_storage_settings = array_diff_key($default_storage_settings, $storage_settings);
+    $this->assertEmpty($missing_storage_settings);
+    // The value we set should be remembered.
+    $this->assertSame('big', $storage_settings['size']);
+
+    $field_settings = $field->setSetting('min', 10)->getSettings();
+    $missing_field_settings = array_diff_key($default_field_settings, $field_settings);
+    $this->assertEmpty($missing_field_settings);
+    $this->assertSame(10, $field_settings['min']);
+
+    $field_settings = $field->setSettings(['max' => 39])->get('settings');
+    $missing_field_settings = array_diff_key($default_field_settings, $field_settings);
+    $this->assertEmpty($missing_field_settings);
+    $this->assertSame(39, $field_settings['max']);
+
+    // Test that saving settings with incomplete settings is not triggering
+    // error, and values are retained.
+    $field_storage->save();
+    $missing_storage_settings = array_diff_key($default_storage_settings, $storage_settings);
+    $this->assertEmpty($missing_storage_settings);
+    // The value we set should be remembered.
+    $this->assertSame('big', $storage_settings['size']);
+
+    $field->save();
+    $missing_field_settings = array_diff_key($default_field_settings, $field_settings);
+    $this->assertEmpty($missing_field_settings);
+    $this->assertSame(39, $field_settings['max']);
+  }
+
+  /**
+   * Tests entity reference settings are normalized on field creation and save.
+   */
+  public function testEntityReferenceSettingsNormalized(): void {
+    $field_storage = FieldStorageConfig::create([
+      'field_name' => 'test_reference',
+      'type' => 'entity_reference',
+      'entity_type' => 'entity_test_with_bundle',
+      'cardinality' => 1,
+      'settings' => [
+        'target_type' => 'entity_test_with_bundle',
+      ],
+    ]);
+    $field_storage->save();
+
+    $field = FieldConfig::create([
+      'field_storage' => $field_storage,
+      'bundle' => 'test',
+      'label' => 'Test Reference',
+      'settings' => [
+        'handler' => 'default',
+      ],
+    ]);
+    $this->assertSame('default:entity_test_with_bundle', $field->getSetting('handler'));
+    // If the handler is changed, it should be normalized again on pre-save.
+    $field->setSetting('handler', 'default')->save();
+    $this->assertSame('default:entity_test_with_bundle', $field->getSetting('handler'));
+  }
+
+}

core/modules/field/tests/src/Kernel/Entity/FieldStorageConfigValidationTest.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\field\Kernel\Entity;
+
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\Core\Config\ConfigEntityValidationTestBase;
+
+/**
+ * Tests validation of field_storage_config entities.
+ *
+ * @group field
+ * @group #slow
+ */
+class FieldStorageConfigValidationTest extends ConfigEntityValidationTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field', 'node', 'user'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->installEntitySchema('user');
+
+    $this->entity = FieldStorageConfig::create([
+      'type' => 'boolean',
+      'field_name' => 'test',
+      'entity_type' => 'user',
+    ]);
+    $this->entity->save();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function testImmutableProperties(array $valid_values = []): void {
+    $valid_values['type'] = 'string';
+    parent::testImmutableProperties($valid_values);
+  }
+
+  /**
+   * Tests that the field type plugin's existence is validated.
+   */
+  public function testFieldTypePluginIsValidated(): void {
+    // The `type` property is immutable, so we need to clone the entity in
+    // order to cleanly change its immutable properties.
+    $this->entity = $this->entity->createDuplicate()
+      ->set('type', 'invalid');
+
+    $this->assertValidationErrors([
+      'type' => "The 'invalid' plugin does not exist.",
+    ]);
+  }
+
+}