adding everything

block_content.info.yml

@@ -0,0 +1,10 @@
+name: 'Block Content'
+type: module
+description: 'Allows the creation of content blocks and block types.'
+package: Core
+version: VERSION
+dependencies:
+  - drupal:block
+  - drupal:text
+  - drupal:user
+configure: entity.block_content.collection

block_content.install

@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * @file
+ * Install, update and uninstall functions for the block_content module.
+ */
+
+use Drupal\block_content\BlockContentStorageSchema;
+use Drupal\Core\Entity\Form\RevisionDeleteForm;
+use Drupal\Core\Entity\Form\RevisionRevertForm;
+use Drupal\Core\Entity\Routing\RevisionHtmlRouteProvider;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Implements hook_update_last_removed().
+ */
+function block_content_update_last_removed() {
+  return 8600;
+}
+
+/**
+ * Update entity definition to handle revision routes.
+ */
+function block_content_update_10100(&$sandbox = NULL): TranslatableMarkup {
+  $entityDefinitionUpdateManager = \Drupal::entityDefinitionUpdateManager();
+  $definition = $entityDefinitionUpdateManager->getEntityType('block_content');
+  $routeProviders = $definition->get('route_provider');
+  $routeProviders['revision'] = RevisionHtmlRouteProvider::class;
+  $definition
+    ->setFormClass('revision-delete', RevisionDeleteForm::class)
+    ->setFormClass('revision-revert', RevisionRevertForm::class)
+    ->set('route_provider', $routeProviders)
+    ->setLinkTemplate('revision-delete-form', '/admin/content/block/{block_content}/revision/{block_content_revision}/delete')
+    ->setLinkTemplate('revision-revert-form', '/admin/content/block/{block_content}/revision/{block_content_revision}/revert')
+    ->setLinkTemplate('version-history', '/admin/content/block/{block_content}/revisions');
+  $entityDefinitionUpdateManager->updateEntityType($definition);
+  return \t('Added revision routes to Content block entity type.');
+}
+
+/**
+ * Remove the unique values constraint from block content info fields.
+ */
+function block_content_update_10200() {
+  $constraint = 'UniqueField';
+  $definition_update_manager = \Drupal::entityDefinitionUpdateManager();
+  $field_storage_definition = $definition_update_manager->getFieldStorageDefinition('info', 'block_content');
+  $constraints = $field_storage_definition->getConstraints();
+  if (isset($constraints[$constraint])) {
+    unset($constraints[$constraint]);
+    $field_storage_definition->setConstraints($constraints);
+    $definition_update_manager->updateFieldStorageDefinition($field_storage_definition);
+  }
+}
+
+/**
+ * Apply index to reusable column.
+ */
+function block_content_update_10300(): void {
+  $manager = \Drupal::entityDefinitionUpdateManager();
+  $entity_type = $manager->getEntityType('block_content')
+    ->setHandlerClass('storage_schema', BlockContentStorageSchema::class);
+  $manager->updateEntityType($entity_type);
+  $manager->updateFieldStorageDefinition(\Drupal::service('entity_field.manager')
+    ->getBaseFieldDefinitions('block_content')['reusable']);
+}

block_content.links.action.yml

@@ -0,0 +1,13 @@
+block_content_type_add:
+  route_name: block_content.type_add
+  title: 'Add block type'
+  appears_on:
+    - entity.block_content_type.collection
+
+block_content_add_action:
+  route_name: block_content.add_page
+  title: 'Add content block'
+  appears_on:
+    - block.admin_library
+    - entity.block_content.collection
+  class: \Drupal\block_content\Plugin\Menu\LocalAction\BlockContentAddLocalAction

block_content.links.contextual.yml

@@ -0,0 +1,4 @@
+block_content.block_edit:
+  title: 'Edit'
+  group: block_content
+  route_name: 'entity.block_content.edit_form'

block_content.links.menu.yml

@@ -0,0 +1,5 @@
+entity.block_content_type.collection:
+  title: 'Block types'
+  parent: system.admin_structure
+  description: 'Create and manage fields, forms, and display settings for your content blocks.'
+  route_name: entity.block_content_type.collection

block_content.links.task.yml

@@ -0,0 +1,19 @@
+entity.block_content.collection:
+  title: Blocks
+  route_name: entity.block_content.collection
+  base_route: system.admin_content
+
+entity.block_content.canonical:
+  title: Edit
+  route_name: entity.block_content.canonical
+  base_route: entity.block_content.canonical
+entity.block_content.delete_form:
+  title: Delete
+  route_name: entity.block_content.delete_form
+  base_route: entity.block_content.canonical
+
+# Default tab for block type editing.
+entity.block_content_type.edit_form:
+  title: 'Edit'
+  route_name: entity.block_content_type.edit_form
+  base_route: entity.block_content_type.edit_form

block_content.module

@@ -0,0 +1,243 @@
+<?php
+
+/**
+ * @file
+ * Allows the creation of content blocks through the user interface.
+ */
+
+use Drupal\block\BlockInterface;
+use Drupal\block_content\BlockContentInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Url;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Core\Database\Query\SelectInterface;
+use Drupal\Core\Database\Query\AlterableInterface;
+use Drupal\Core\Database\Query\ConditionInterface;
+
+/**
+ * Implements hook_help().
+ */
+function block_content_help($route_name, RouteMatchInterface $route_match) {
+  switch ($route_name) {
+    case 'help.page.block_content':
+      $field_ui = \Drupal::moduleHandler()->moduleExists('field_ui') ? Url::fromRoute('help.page', ['name' => 'field_ui'])->toString() : '#';
+      $output = '';
+      $output .= '<h2>' . t('About') . '</h2>';
+      $output .= '<p>' . t('The Block Content module allows you to create and manage custom <em>block types</em> and <em>content-containing blocks</em>. For more information, see the <a href=":online-help">online documentation for the Block Content module</a>.', [':online-help' => 'https://www.drupal.org/documentation/modules/block_content']) . '</p>';
+      $output .= '<h2>' . t('Uses') . '</h2>';
+      $output .= '<dl>';
+      $output .= '<dt>' . t('Creating and managing block types') . '</dt>';
+      $output .= '<dd>' . t('Users with the <em>Administer blocks</em> permission can create and edit block types with fields and display settings, from the <a href=":types">Block types</a> page under the Structure menu. For more information about managing fields and display settings, see the <a href=":field-ui">Field UI module help</a> and <a href=":field">Field module help</a>.', [':types' => Url::fromRoute('entity.block_content_type.collection')->toString(), ':field-ui' => $field_ui, ':field' => Url::fromRoute('help.page', ['name' => 'field'])->toString()]) . '</dd>';
+      $output .= '<dt>' . t('Creating content blocks') . '</dt>';
+      $output .= '<dd>' . t('Users with the <em>Administer blocks</em> permission can create, edit, and delete content blocks of each defined block type, from the <a href=":block-library">Content blocks page</a>. After creating a block, place it in a region from the <a href=":blocks">Block layout page</a>, just like blocks provided by other modules.', [':blocks' => Url::fromRoute('block.admin_display')->toString(), ':block-library' => Url::fromRoute('entity.block_content.collection')->toString()]) . '</dd>';
+      $output .= '</dl>';
+      return $output;
+  }
+}
+
+/**
+ * Implements hook_theme().
+ */
+function block_content_theme($existing, $type, $theme, $path) {
+  return [
+    'block_content_add_list' => [
+      'variables' => ['content' => NULL],
+      'file' => 'block_content.pages.inc',
+    ],
+  ];
+}
+
+/**
+ * Implements hook_entity_type_alter().
+ */
+function block_content_entity_type_alter(array &$entity_types) {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+  // Add a translation handler for fields if the language module is enabled.
+  if (\Drupal::moduleHandler()->moduleExists('language')) {
+    $translation = $entity_types['block_content']->get('translation');
+    $translation['block_content'] = TRUE;
+    $entity_types['block_content']->set('translation', $translation);
+  }
+
+  // Swap out the default EntityChanged constraint with a custom one with
+  // different logic for inline blocks.
+  $constraints = $entity_types['block_content']->getConstraints();
+  unset($constraints['EntityChanged']);
+  $constraints['BlockContentEntityChanged'] = NULL;
+  $entity_types['block_content']->setConstraints($constraints);
+}
+
+/**
+ * Adds the default body field to a block type.
+ *
+ * @param string $block_type_id
+ *   Id of the block type.
+ * @param string $label
+ *   (optional) The label for the body instance. Defaults to 'Body'
+ *
+ * @return \Drupal\field\Entity\FieldConfig
+ *   A Body field object.
+ */
+function block_content_add_body_field($block_type_id, $label = 'Body') {
+  // Add or remove the body field, as needed.
+  $field = FieldConfig::loadByName('block_content', $block_type_id, 'body');
+  if (empty($field)) {
+    $field = FieldConfig::create([
+      'field_storage' => FieldStorageConfig::loadByName('block_content', 'body'),
+      'bundle' => $block_type_id,
+      'label' => $label,
+      'settings' => [
+        'display_summary' => FALSE,
+        'allowed_formats' => [],
+      ],
+    ]);
+    $field->save();
+
+    /** @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface $display_repository */
+    $display_repository = \Drupal::service('entity_display.repository');
+
+    // Assign widget settings for the default form mode.
+    $display_repository->getFormDisplay('block_content', $block_type_id)
+      ->setComponent('body', [
+        'type' => 'text_textarea_with_summary',
+      ])
+      ->save();
+
+    // Assign display settings for default view mode.
+    $display_repository->getViewDisplay('block_content', $block_type_id)
+      ->setComponent('body', [
+        'label' => 'hidden',
+        'type' => 'text_default',
+      ])
+      ->save();
+  }
+
+  return $field;
+}
+
+/**
+ * Implements hook_query_TAG_alter().
+ *
+ * Alters any 'entity_reference' query where the entity type is
+ * 'block_content' and the query has the tag 'block_content_access'.
+ *
+ * These queries should only return reusable blocks unless a condition on
+ * 'reusable' is explicitly set.
+ *
+ * Block_content entities that are not reusable should by default not be
+ * selectable as entity reference values. A module can still create an instance
+ * of \Drupal\Core\Entity\EntityReferenceSelection\SelectionInterface
+ * that will allow selection of non-reusable blocks by explicitly setting
+ * a condition on the 'reusable' field.
+ *
+ * @see \Drupal\block_content\BlockContentAccessControlHandler
+ */
+function block_content_query_entity_reference_alter(AlterableInterface $query) {
+  if ($query instanceof SelectInterface && $query->getMetaData('entity_type') === 'block_content' && $query->hasTag('block_content_access')) {
+    $data_table = \Drupal::entityTypeManager()->getDefinition('block_content')->getDataTable();
+    if (array_key_exists($data_table, $query->getTables()) && !_block_content_has_reusable_condition($query->conditions(), $query->getTables())) {
+      $query->condition("$data_table.reusable", TRUE);
+    }
+  }
+}
+
+/**
+ * Utility function to find nested conditions using the reusable field.
+ *
+ * @todo Replace this function with a call to the API in
+ *   https://www.drupal.org/project/drupal/issues/2984930
+ *
+ * @param array $condition
+ *   The condition or condition group to check.
+ * @param array $tables
+ *   The tables from the related select query.
+ *
+ * @see \Drupal\Core\Database\Query\SelectInterface::getTables
+ *
+ * @return bool
+ *   Whether the conditions contain any condition using the reusable field.
+ */
+function _block_content_has_reusable_condition(array $condition, array $tables) {
+  // If this is a condition group call this function recursively for each nested
+  // condition until a condition is found that return TRUE.
+  if (isset($condition['#conjunction'])) {
+    foreach (array_filter($condition, 'is_array') as $nested_condition) {
+      if (_block_content_has_reusable_condition($nested_condition, $tables)) {
+        return TRUE;
+      }
+    }
+    return FALSE;
+  }
+  if (isset($condition['field'])) {
+    $field = $condition['field'];
+    if (is_object($field) && $field instanceof ConditionInterface) {
+      return _block_content_has_reusable_condition($field->conditions(), $tables);
+    }
+    $field_parts = explode('.', $field);
+    $data_table = \Drupal::entityTypeManager()->getDefinition('block_content')->getDataTable();
+    foreach ($tables as $table) {
+      if ($table['table'] === $data_table && $field_parts[0] === $table['alias'] && $field_parts[1] === 'reusable') {
+        return TRUE;
+      }
+    }
+
+  }
+  return FALSE;
+}
+
+/**
+ * Implements hook_theme_suggestions_HOOK_alter() for block templates.
+ */
+function block_content_theme_suggestions_block_alter(array &$suggestions, array $variables) {
+  $suggestions_new = [];
+  $content = $variables['elements']['content'];
+
+  $block_content = $variables['elements']['content']['#block_content'] ?? NULL;
+
+  if ($block_content instanceof BlockContentInterface) {
+    $bundle = $content['#block_content']->bundle();
+    $view_mode = strtr($variables['elements']['#configuration']['view_mode'], '.', '_');
+
+    $suggestions_new[] = 'block__block_content__view__' . $view_mode;
+    $suggestions_new[] = 'block__block_content__type__' . $bundle;
+    $suggestions_new[] = 'block__block_content__view_type__' . $bundle . '__' . $view_mode;
+
+    if (!empty($variables['elements']['#id'])) {
+      $suggestions_new[] = 'block__block_content__id__' . $variables['elements']['#id'];
+      $suggestions_new[] = 'block__block_content__id_view__' . $variables['elements']['#id'] . '__' . $view_mode;
+    }
+
+    // Remove duplicate block__block_content.
+    $suggestions = array_unique($suggestions);
+    array_splice($suggestions, 1, 0, $suggestions_new);
+  }
+
+  return $suggestions;
+}
+
+/**
+ * Implements hook_entity_operation().
+ */
+function block_content_entity_operation(EntityInterface $entity): array {
+  $operations = [];
+  if ($entity instanceof BlockInterface) {
+    $plugin = $entity->getPlugin();
+    if ($plugin->getBaseId() === 'block_content') {
+      $custom_block = \Drupal::entityTypeManager()->getStorage('block_content')->loadByProperties([
+        'uuid' => $plugin->getDerivativeId(),
+      ]);
+      $custom_block = reset($custom_block);
+      if ($custom_block && $custom_block->access('update')) {
+        $operations['block-edit'] = [
+          'title' => t('Edit block'),
+          'url' => $custom_block->toUrl('edit-form')->setOptions([]),
+          'weight' => 50,
+        ];
+      }
+    }
+  }
+
+  return $operations;
+}

block_content.pages.inc

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * @file
+ * Provides page callbacks for content blocks.
+ */
+
+use Drupal\Core\Link;
+use Drupal\Core\Url;
+
+/**
+ * Prepares variables for a block type creation list templates.
+ *
+ * Default template: block-content-add-list.html.twig.
+ *
+ * @param array $variables
+ *   An associative array containing:
+ *   - content: An array of block types.
+ *
+ * @see block_content_add_page()
+ */
+function template_preprocess_block_content_add_list(&$variables) {
+  $variables['types'] = [];
+  $query = \Drupal::request()->query->all();
+  foreach ($variables['content'] as $type) {
+    $variables['types'][$type->id()] = [
+      'link' => Link::fromTextAndUrl($type->label(), Url::fromRoute('block_content.add_form', ['block_content_type' => $type->id()], ['query' => $query]))->toString(),
+      'description' => [
+        '#markup' => $type->getDescription(),
+      ],
+      'title' => $type->label(),
+      'localized_options' => [
+        'query' => $query,
+      ],
+    ];
+  }
+}

block_content.permissions.yml

@@ -0,0 +1,16 @@
+permission_callbacks:
+  - \Drupal\block_content\BlockContentPermissions::blockTypePermissions
+
+access block library:
+  title: 'Access the Content blocks overview page'
+  description: 'Get an overview of all content blocks.'
+
+administer block types:
+  title: 'Administer block types'
+  description: 'Maintain the block types of block content available and the fields that are associated with those types.'
+  restrict access: TRUE
+
+administer block content:
+  title: 'Administer block content'
+  description: 'View, edit and delete all block content regardless of permission restrictions.'
+  restrict access: TRUE

block_content.post_update.php

@@ -0,0 +1,94 @@
+<?php
+
+/**
+ * @file
+ * Post update functions for Content Block.
+ */
+
+use Drupal\block_content\BlockContentTypeInterface;
+use Drupal\Core\Config\Entity\ConfigEntityUpdater;
+use Drupal\user\Entity\Role;
+use Drupal\views\Entity\View;
+
+/**
+ * Implements hook_removed_post_updates().
+ */
+function block_content_removed_post_updates() {
+  return [
+    'block_content_post_update_add_views_reusable_filter' => '9.0.0',
+  ];
+}
+
+/**
+ * Clear the entity type cache.
+ */
+function block_content_post_update_entity_changed_constraint() {
+  // Empty post_update hook.
+}
+
+/**
+ * Moves the custom block library to Content.
+ */
+function block_content_post_update_move_custom_block_library() {
+
+  if (!\Drupal::service('module_handler')->moduleExists('views')) {
+    return;
+  }
+  if (!$view = View::load('block_content')) {
+    return;
+  }
+
+  $display =& $view->getDisplay('page_1');
+  if (empty($display) || $display['display_options']['path'] !== 'admin/structure/block/block-content') {
+    return;
+  }
+
+  $display['display_options']['path'] = 'admin/content/block';
+  $menu =& $display['display_options']['menu'];
+  $menu['title'] = 'Blocks';
+  $menu['description'] = 'Create and edit block content.';
+  $menu['expanded'] = FALSE;
+  $menu['parent'] = 'system.admin_content';
+  $view->set('label', 'Content blocks');
+
+  $view->save();
+}
+
+/**
+ * Update block_content 'block library' view permission.
+ */
+function block_content_post_update_block_library_view_permission() {
+  $config_factory = \Drupal::configFactory();
+  $config = $config_factory->getEditable('views.view.block_content');
+  $current_perm = $config->get('display.default.display_options.access.options.perm');
+  if ($current_perm === 'administer blocks') {
+    $config->set('display.default.display_options.access.options.perm', 'access block library')
+      ->save(TRUE);
+  }
+}
+
+/**
+ * Update permissions for users with "administer blocks" permission.
+ */
+function block_content_post_update_sort_permissions(&$sandbox = NULL) {
+  \Drupal::classResolver(ConfigEntityUpdater::class)->update($sandbox, 'user_role', function (Role $role) {
+    if ($role->hasPermission('administer blocks')) {
+      $role->grantPermission('administer block content');
+      $role->grantPermission('access block library');
+      $role->grantPermission('administer block types');
+      return TRUE;
+    }
+    return FALSE;
+  });
+}
+
+/**
+ * Update configuration for revision type.
+ */
+function block_content_post_update_revision_type(&$sandbox = NULL) {
+  \Drupal::classResolver(ConfigEntityUpdater::class)
+    ->update($sandbox, 'block_content_type', function (BlockContentTypeInterface $block_content_type) {
+      $block_content_type->set('revision', (bool) $block_content_type->get('revision'));
+      return TRUE;
+    });
+}

block_content.routing.yml

@@ -0,0 +1,132 @@
+block_content.add_page:
+  path: '/block/add'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::add'
+    _title: 'Add content block'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_create_any_access: 'block_content'
+
+# @todo Deprecate this route once
+#   https://www.drupal.org/project/drupal/issues/3159210 is fixed, or remove
+#   it in Drupal 11.
+# @see https://www.drupal.org/node/3320855
+entity.block_content_type.collection.bc:
+  path: '/admin/structure/block/block-content/types'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::blockContentTypeRedirect'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _permission: 'administer block types'
+
+# @todo Deprecate this route once
+#   https://www.drupal.org/project/drupal/issues/3159210 is fixed, or remove
+#   it in Drupal 11.
+# @see https://www.drupal.org/node/3320855
+entity.block_content_type.edit_form.bc:
+  path: '/admin/structure/block/block-content/manage/{block_content_type}'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::blockContentTypeRedirect'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _permission: 'administer block types'
+
+block_content.add_form:
+  path: '/block/add/{block_content_type}'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::addForm'
+    _title_callback: '\Drupal\block_content\Controller\BlockContentController::getAddFormTitle'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_create_access: 'block_content:{block_content_type}'
+
+entity.block_content.canonical:
+  path: '/admin/content/block/{block_content}'
+  defaults:
+    _entity_form: 'block_content.edit'
+    _title_callback: '\Drupal\Core\Entity\Controller\EntityController::title'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_access: 'block_content.update'
+    block_content: \d+
+
+entity.block_content.edit_form:
+  path: '/admin/content/block/{block_content}'
+  defaults:
+    _entity_form: 'block_content.edit'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_access: 'block_content.update'
+    block_content: \d+
+
+# @todo Deprecate this route once
+#   https://www.drupal.org/project/drupal/issues/3159210 is fixed, or remove
+#   it in Drupal 11.
+# @see https://www.drupal.org/node/2317981
+entity.block_content.edit_form.bc:
+  path: '/block/{block_content}'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::editRedirect'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_access: 'block_content.update'
+    block_content: \d+
+
+entity.block_content.delete_form:
+  path: '/admin/content/block/{block_content}/delete'
+  defaults:
+    _entity_form: 'block_content.delete'
+    _title: 'Delete'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_access: 'block_content.delete'
+    block_content: \d+
+
+# @todo Deprecate this route once
+#   https://www.drupal.org/project/drupal/issues/3159210 is fixed, or remove
+#   it in Drupal 11.
+# @see https://www.drupal.org/node/2317981
+entity.block_content.delete_form.bc:
+  path: '/block/{block_content}/delete'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::editRedirect'
+  options:
+    _admin_route: TRUE
+  requirements:
+    _entity_access: 'block_content.delete'
+    block_content: \d+
+
+block_content.type_add:
+  path: '/admin/structure/block-content/add'
+  defaults:
+    _entity_form: 'block_content_type.add'
+    _title: 'Add'
+  requirements:
+    _entity_create_access: 'block_content_type'
+
+entity.block_content.collection:
+  path: '/admin/content/block'
+  defaults:
+    _title: 'Content blocks'
+    _entity_list: 'block_content'
+  requirements:
+    _permission: 'access block library+administer block content'
+
+# @todo Deprecate this route once
+#   https://www.drupal.org/project/drupal/issues/3159210 is fixed, or remove
+#   it in Drupal 11.
+# @see https://www.drupal.org/node/3320855
+entity.block_content.collection.bc:
+  path: '/admin/structure/block/block-content'
+  defaults:
+    _controller: '\Drupal\block_content\Controller\BlockContentController::blockLibraryRedirect'
+  requirements:
+    _permission: 'access block library+administer block content'

block_content.services.yml

@@ -0,0 +1,11 @@
+services:
+  _defaults:
+    autoconfigure: true
+  block_content.uuid_lookup:
+    class: \Drupal\block_content\BlockContentUuidLookup
+    arguments: ['@cache.bootstrap', '@lock', '@entity_type.manager']
+    tags:
+      - { name: needs_destruction }
+  block_content.bc_subscriber:
+    class: Drupal\block_content\Routing\RouteSubscriber
+    arguments: ['@entity_type.manager', '@module_handler']

config/install/core.entity_view_mode.block_content.full.yml

@@ -0,0 +1,10 @@
+langcode: en
+status: false
+dependencies:
+  module:
+    - block_content
+id: block_content.full
+label: Full
+description: ''
+targetEntityType: block_content
+cache: true

config/install/field.storage.block_content.body.yml

@@ -0,0 +1,18 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+    - text
+id: block_content.body
+field_name: body
+entity_type: block_content
+type: text_with_summary
+settings: {  }
+module: text
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
+persist_with_no_fields: true
+custom_storage: false

config/optional/views.view.block_content.yml

@@ -0,0 +1,550 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+    - user
+id: block_content
+label: 'Content blocks'
+module: views
+description: 'Find and manage content blocks.'
+tag: default
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    id: default
+    display_title: Default
+    display_plugin: default
+    position: 0
+    display_options:
+      title: 'Content blocks'
+      fields:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: null
+          entity_field: info
+          plugin_id: field
+          label: 'Block description'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: string
+          settings:
+            link_to_entity: true
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        type:
+          id: type
+          table: block_content_field_data
+          field: type
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: type
+          plugin_id: field
+          label: 'Block type'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: target_id
+          type: entity_reference_label
+          settings:
+            link: false
+          group_column: target_id
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        changed:
+          id: changed
+          table: block_content_field_data
+          field: changed
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: changed
+          plugin_id: field
+          label: Updated
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          type: timestamp
+          settings:
+            date_format: short
+            custom_date_format: ''
+            timezone: ''
+            tooltip:
+              date_format: long
+              custom_date_format: ''
+            time_diff:
+              enabled: false
+              future_format: '@interval hence'
+              past_format: '@interval ago'
+              granularity: 2
+              refresh: 60
+        operations:
+          id: operations
+          table: block_content
+          field: operations
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          plugin_id: entity_operations
+          label: Operations
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          destination: true
+      pager:
+        type: mini
+        options:
+          offset: 0
+          pagination_heading_level: h4
+          items_per_page: 50
+          total_pages: null
+          id: 0
+          tags:
+            next: 'Next ›'
+            previous: '‹ Previous'
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: true
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      access:
+        type: perm
+        options:
+          perm: 'access block library'
+      cache:
+        type: tag
+        options: {  }
+      empty:
+        area_text_custom:
+          id: area_text_custom
+          table: views
+          field: area_text_custom
+          relationship: none
+          group_type: group
+          admin_label: ''
+          plugin_id: text_custom
+          empty: true
+          content: 'There are no content blocks available.'
+          tokenize: false
+        block_content_listing_empty:
+          id: block_content_listing_empty
+          table: block_content
+          field: block_content_listing_empty
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          plugin_id: block_content_listing_empty
+          label: ''
+          empty: true
+      sorts: {  }
+      arguments: {  }
+      filters:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: info
+          plugin_id: string
+          operator: contains
+          value: ''
+          group: 1
+          exposed: true
+          expose:
+            operator_id: info_op
+            label: 'Block description'
+            description: ''
+            use_operator: false
+            operator: info_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: info
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+        type:
+          id: type
+          table: block_content_field_data
+          field: type
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: type
+          plugin_id: bundle
+          operator: in
+          value: {  }
+          group: 1
+          exposed: true
+          expose:
+            operator_id: type_op
+            label: 'Block type'
+            description: ''
+            use_operator: false
+            operator: type_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: type
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+            reduce: false
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+        reusable:
+          id: reusable
+          table: block_content_field_data
+          field: reusable
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: reusable
+          plugin_id: boolean
+          operator: '='
+          value: '1'
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+      style:
+        type: table
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          columns:
+            info: info
+            type: type
+            changed: changed
+            operations: operations
+          default: changed
+          info:
+            info:
+              sortable: true
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            type:
+              sortable: true
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            changed:
+              sortable: true
+              default_sort_order: desc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            operations:
+              sortable: false
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+          override: true
+          sticky: false
+          summary: ''
+          empty_table: true
+          caption: ''
+          description: ''
+      row:
+        type: fields
+      query:
+        type: views_query
+        options:
+          query_comment: ''
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_tags: {  }
+      relationships: {  }
+      header: {  }
+      footer: {  }
+      display_extenders: {  }
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+        - user.permissions
+      tags: {  }
+  page_1:
+    id: page_1
+    display_title: Page
+    display_plugin: page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: admin/content/block
+      menu:
+        type: tab
+        title: 'Blocks'
+        description: 'Create and edit content blocks.'
+        weight: 0
+        menu_name: admin
+        parent: system.admin_content
+        context: '0'
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+        - user.permissions
+      tags: {  }

config/schema/block_content.schema.yml

@@ -0,0 +1,24 @@
+# Schema for the configuration files of the Content Block module.
+
+block_content.type.*:
+  type: config_entity
+  label: 'Block type settings'
+  mapping:
+    id:
+      type: machine_name
+      label: 'ID'
+    label:
+      type: required_label
+      label: 'Label'
+    revision:
+      type: boolean
+      label: 'Whether a new revision should be created by default'
+    description:
+      type: text
+      label: 'Description'
+      nullable: true
+      constraints:
+        NotBlank:
+          allowNull: true
+  constraints:
+    FullyValidatable: ~

help_topics/block_content.add.html.twig

@@ -0,0 +1,20 @@
+---
+label: 'Creating a content block'
+related:
+  - block.overview
+  - block.configure
+  - block.place
+  - block_content.type
+---
+{% set library_link_text %}{% trans %}Content blocks{% endtrans %}{% endset %}
+{% set library_link = render_var(help_route_link(library_link_text, 'entity.block_content.collection')) %}
+<h2>{% trans %}Goal{% endtrans %}</h2>
+<p>{% trans %}Create a content block, which can later be placed on the site.{% endtrans %}</p>
+<h2>{% trans %}Steps{% endtrans %}</h2>
+<ol>
+  <li>{% trans %}In the <em>Manage</em> administrative menu, navigate to <em>Content</em>.{% endtrans %}</li>
+  <li>{% trans %}Open the {{ library_link }} tab.{% endtrans %}</li>
+  <li>{% trans %}Click <em>Add content block</em>. If you have more than one block type defined on your site, click the name of the type you want to create.{% endtrans %}</li>
+  <li>{% trans %}Enter a description of your block (to be shown to administrators) and the body text for your block.{% endtrans %}</li>
+  <li>{% trans %}Click <em>Save</em>.{% endtrans %}</li>
+</ol>

help_topics/block_content.type.html.twig

@@ -0,0 +1,24 @@
+---
+label: 'Defining a block type'
+related:
+  - block.overview
+  - block.configure
+  - block.place
+  - block_content.add
+  - field_ui.add_field
+  - field_ui.manage_form
+  - field_ui.manage_display
+---
+{% set types_link_text %}{% trans %}Block types{% endtrans %}{% endset %}
+{% set types_link = render_var(help_route_link(types_link_text, 'entity.block_content_type.collection')) %}
+<h2>{% trans %}Goal{% endtrans %}</h2>
+<p>{% trans %}Define a block type and its fields.{% endtrans %}</p>
+<h2>{% trans %}Steps{% endtrans %}</h2>
+<ol>
+  <li>{% trans %}In the <em>Manage</em> administrative menu, navigate to <em>Structure</em> &gt; <em>{{ types_link }}</em>.{% endtrans %}</li>
+  <li>{% trans %}Click  <em>Add block type</em>.{% endtrans %}</li>
+  <li>{% trans %}Enter a label for this block type (shown in the administrative interface). Optionally, edit the automatically-generated machine name or the description.{% endtrans %}</li>
+  <li>{% trans %}Click <em>Save</em>. You will be returned to the <em>Block types</em> page.{% endtrans %}</li>
+  <li>{% trans %}Click <em>Manage fields</em> in the row of your new block type, and add the desired fields to your block type.{% endtrans %}</li>
+  <li>{% trans %}Optionally, click <em>Manage form display</em> or <em>Manage display</em> to change the editing form or field display for your block type.{% endtrans %}</li>
+</ol>

migrations/block_content_body_field.yml

@@ -0,0 +1,38 @@
+id: block_content_body_field
+label: Block content body field configuration
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+  - Configuration
+source:
+  plugin: embedded_data
+  data_rows:
+    -
+      entity_type: block_content
+      bundle: basic
+      field_name: body
+      label: Body
+      display_summary: false
+      allowed_formats: {  }
+  ids:
+    entity_type:
+      type: string
+    bundle:
+      type: string
+    field_name:
+      type: string
+  source_module: block
+process:
+  entity_type: entity_type
+  bundle: bundle
+  field_name: field_name
+  label: label
+  'settings/display_summary': display_summary
+destination:
+  plugin: entity:field_config
+migration_dependencies:
+  required:
+    - block_content_type
+provider:
+  - block_content
+  - migrate_drupal

migrations/block_content_entity_display.yml

@@ -0,0 +1,40 @@
+id: block_content_entity_display
+label: Body field display configuration
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+  - Configuration
+source:
+  plugin: embedded_data
+  data_rows:
+    -
+      entity_type: block_content
+      bundle: basic
+      view_mode: default
+      field_name: body
+      options:
+        label: hidden
+  ids:
+    entity_type:
+      type: string
+    bundle:
+      type: string
+    view_mode:
+      type: string
+    field_name:
+      type: string
+  source_module: block
+process:
+  entity_type: entity_type
+  bundle: bundle
+  view_mode: view_mode
+  field_name: field_name
+  options: options
+destination:
+  plugin: component_entity_display
+migration_dependencies:
+  required:
+    - block_content_body_field
+provider:
+  - block_content
+  - migrate_drupal

migrations/block_content_entity_form_display.yml

@@ -0,0 +1,37 @@
+id: block_content_entity_form_display
+label: Body field form display configuration
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+  - Configuration
+source:
+  plugin: embedded_data
+  data_rows:
+    -
+      entity_type: block_content
+      bundle: basic
+      form_mode: default
+      field_name: body
+  ids:
+    entity_type:
+      type: string
+    bundle:
+      type: string
+    form_mode:
+      type: string
+    field_name:
+      type: string
+  source_module: block
+process:
+  entity_type: entity_type
+  bundle: bundle
+  form_mode: form_mode
+  field_name: field_name
+destination:
+  plugin: component_entity_form_display
+migration_dependencies:
+  required:
+    - block_content_body_field
+provider:
+  - block_content
+  - migrate_drupal

migrations/block_content_type.yml

@@ -0,0 +1,24 @@
+id: block_content_type
+label: Block content type
+migration_tags:
+  - Drupal 6
+  - Drupal 7
+  - Configuration
+source:
+  plugin: embedded_data
+  data_rows:
+    -
+      id: basic
+      label: Basic
+  ids:
+    id:
+      type: string
+  source_module: block
+process:
+  id: id
+  label: label
+destination:
+  plugin: entity:block_content_type
+provider:
+  - block_content
+  - migrate_drupal

migrations/d6_custom_block.yml

@@ -0,0 +1,24 @@
+id: d6_custom_block
+label: Content blocks
+audit: true
+migration_tags:
+  - Drupal 6
+  - Content
+source:
+  plugin: d6_box
+process:
+  id: bid
+  info: info
+  'body/format':
+    plugin: migration_lookup
+    migration: d6_filter_format
+    source: format
+  'body/value': body
+destination:
+  plugin: entity:block_content
+  default_bundle: basic
+  no_stub: true
+migration_dependencies:
+  required:
+    - d6_filter_format
+    - block_content_body_field

migrations/d7_custom_block.yml

@@ -0,0 +1,24 @@
+id: d7_custom_block
+label: Content blocks
+audit: true
+migration_tags:
+  - Drupal 7
+  - Content
+source:
+  plugin: d7_block_custom
+process:
+  id: bid
+  info: info
+  'body/format':
+    plugin: migration_lookup
+    migration: d7_filter_format
+    source: format
+  'body/value': body
+destination:
+  plugin: entity:block_content
+  default_bundle: basic
+  no_stub: true
+migration_dependencies:
+  required:
+    - d7_filter_format
+    - block_content_body_field

migrations/state/block_content.migrate_drupal.yml

@@ -0,0 +1,5 @@
+finished:
+  6:
+    block: block_content
+  7:
+    block: block_content

src/Access/AccessGroupAnd.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Drupal\block_content\Access;
+
+use Drupal\Core\Access\AccessibleInterface;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * An access group where all the dependencies must be allowed.
+ *
+ * @internal
+ */
+class AccessGroupAnd implements AccessibleInterface {
+
+  /**
+   * The access dependencies.
+   *
+   * @var \Drupal\Core\Access\AccessibleInterface[]
+   */
+  protected $dependencies = [];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addDependency(AccessibleInterface $dependency) {
+    $this->dependencies[] = $dependency;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function access($operation, ?AccountInterface $account = NULL, $return_as_object = FALSE) {
+    $access_result = AccessResult::neutral();
+    foreach (array_slice($this->dependencies, 1) as $dependency) {
+      $access_result = $access_result->andIf($dependency->access($operation, $account, TRUE));
+    }
+    return $return_as_object ? $access_result : $access_result->isAllowed();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDependencies() {
+    return $this->dependencies;
+  }
+
+}

src/Access/DependentAccessInterface.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace Drupal\block_content\Access;
+
+/**
+ * Interface for AccessibleInterface objects that have an access dependency.
+ *
+ * Objects should implement this interface when their access depends on access
+ * to another object that implements \Drupal\Core\Access\AccessibleInterface.
+ * This interface simply provides the getter method for the access
+ * dependency object. Objects that implement this interface are responsible for
+ * checking access of the access dependency because the dependency may not take
+ * effect in all cases. For instance an entity may only need the access
+ * dependency set when it is embedded within another entity and its access
+ * should be dependent on access to the entity in which it is embedded.
+ *
+ * To check the access to the dependency the object implementing this interface
+ * can use code like this:
+ * @code
+ * $accessible->getAccessDependency()->access($op, $account, TRUE);
+ * @endcode
+ *
+ * @internal
+ */
+interface DependentAccessInterface {
+
+  /**
+   * Gets the access dependency.
+   *
+   * @return \Drupal\Core\Access\AccessibleInterface|null
+   *   The access dependency or NULL if none has been set.
+   */
+  public function getAccessDependency();
+
+}

src/Access/RefinableDependentAccessInterface.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Drupal\block_content\Access;
+
+use Drupal\Core\Access\AccessibleInterface;
+
+/**
+ * An interface to allow adding an access dependency.
+ *
+ * @internal
+ */
+interface RefinableDependentAccessInterface extends DependentAccessInterface {
+
+  /**
+   * Sets the access dependency.
+   *
+   * If an access dependency is already set this will replace the existing
+   * dependency.
+   *
+   * @param \Drupal\Core\Access\AccessibleInterface $access_dependency
+   *   The object upon which access depends.
+   *
+   * @return $this
+   */
+  public function setAccessDependency(AccessibleInterface $access_dependency);
+
+  /**
+   * Adds an access dependency into the existing access dependency.
+   *
+   * If no existing dependency is currently set this will set the dependency
+   * will be set to the new value.
+   *
+   * If there is an existing dependency and it is not an instance of
+   * AccessGroupAnd the dependency will be set as a new AccessGroupAnd
+   * instance with the existing and new dependencies as the members of the
+   * group.
+   *
+   * If there is an existing dependency and it is an instance of AccessGroupAnd
+   * the dependency will be added to the existing access group.
+   *
+   * @param \Drupal\Core\Access\AccessibleInterface $access_dependency
+   *   The access dependency to merge.
+   *
+   * @return $this
+   */
+  public function addAccessDependency(AccessibleInterface $access_dependency);
+
+}

src/Access/RefinableDependentAccessTrait.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Drupal\block_content\Access;
+
+use Drupal\Core\Access\AccessibleInterface;
+
+/**
+ * Trait for \Drupal\block_content\Access\RefinableDependentAccessInterface.
+ *
+ * @internal
+ */
+trait RefinableDependentAccessTrait {
+
+  /**
+   * The access dependency.
+   *
+   * @var \Drupal\Core\Access\AccessibleInterface
+   */
+  protected $accessDependency;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setAccessDependency(AccessibleInterface $access_dependency) {
+    $this->accessDependency = $access_dependency;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAccessDependency() {
+    return $this->accessDependency;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addAccessDependency(AccessibleInterface $access_dependency) {
+    if (empty($this->accessDependency)) {
+      $this->accessDependency = $access_dependency;
+      return $this;
+    }
+    if (!$this->accessDependency instanceof AccessGroupAnd) {
+      $accessGroup = new AccessGroupAnd();
+      $this->accessDependency = $accessGroup->addDependency($this->accessDependency);
+    }
+    $this->accessDependency->addDependency($access_dependency);
+    return $this;
+  }
+
+}

src/BlockContentAccessControlHandler.php

@@ -0,0 +1,116 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\block_content\Access\DependentAccessInterface;
+use Drupal\block_content\Event\BlockContentGetDependencyEvent;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Access\AccessResultInterface;
+use Drupal\Core\Entity\EntityAccessControlHandler;
+use Drupal\Core\Entity\EntityHandlerInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Session\AccountInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
+
+/**
+ * Defines the access control handler for the content block entity type.
+ *
+ * @see \Drupal\block_content\Entity\BlockContent
+ */
+class BlockContentAccessControlHandler extends EntityAccessControlHandler implements EntityHandlerInterface {
+
+  /**
+   * The event dispatcher.
+   *
+   * @var \Symfony\Contracts\EventDispatcher\EventDispatcherInterface
+   */
+  protected $eventDispatcher;
+
+  /**
+   * BlockContentAccessControlHandler constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type.
+   * @param \Symfony\Contracts\EventDispatcher\EventDispatcherInterface $dispatcher
+   *   The event dispatcher.
+   */
+  public function __construct(EntityTypeInterface $entity_type, EventDispatcherInterface $dispatcher) {
+    parent::__construct($entity_type);
+    $this->eventDispatcher = $dispatcher;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
+    return new static(
+      $entity_type,
+      $container->get('event_dispatcher')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
+    assert($entity instanceof BlockContentInterface);
+    $bundle = $entity->bundle();
+    $forbidIfNotReusable = fn (): AccessResultInterface => AccessResult::forbiddenIf($entity->isReusable() === FALSE, sprintf('Block content must be reusable to use `%s` operation', $operation));
+    $access = AccessResult::allowedIfHasPermissions($account, ['administer block content']);
+    if (!$access->isAllowed()) {
+      $access = match ($operation) {
+        // Allow view and update access to user with the 'edit any (type) block
+        // content' permission or the 'administer block content' permission.
+        'view' => AccessResult::allowedIf($entity->isPublished())
+          ->orIf(AccessResult::allowedIfHasPermission($account, 'access block library')),
+        'update' => AccessResult::allowedIfHasPermission($account, 'edit any ' . $bundle . ' block content'),
+        'delete' => AccessResult::allowedIfHasPermission($account, 'delete any ' . $bundle . ' block content'),
+        // Revisions.
+        'view revision', 'view all revisions' => AccessResult::allowedIfHasPermission($account, 'view any ' . $bundle . ' block content history'),
+        'revert' => AccessResult::allowedIfHasPermission($account, 'revert any ' . $bundle . ' block content revisions')
+          ->orIf($forbidIfNotReusable()),
+        'delete revision' => AccessResult::allowedIfHasPermission($account, 'delete any ' . $bundle . ' block content revisions')
+          ->orIf($forbidIfNotReusable()),
+
+        default => parent::checkAccess($entity, $operation, $account),
+      };
+    }
+
+    // Add the entity as a cacheable dependency because access will at least be
+    // determined by whether the block is reusable.
+    $access->addCacheableDependency($entity);
+    if ($entity->isReusable() === FALSE && $access->isForbidden() !== TRUE) {
+      if (!$entity instanceof DependentAccessInterface) {
+        throw new \LogicException("Non-reusable block entities must implement \Drupal\block_content\Access\DependentAccessInterface for access control.");
+      }
+      $dependency = $entity->getAccessDependency();
+      if (empty($dependency)) {
+        // If an access dependency has not been set let modules set one.
+        $event = new BlockContentGetDependencyEvent($entity);
+        $this->eventDispatcher->dispatch($event, BlockContentEvents::BLOCK_CONTENT_GET_DEPENDENCY);
+        $dependency = $event->getAccessDependency();
+        if (empty($dependency)) {
+          return AccessResult::forbidden("Non-reusable blocks must set an access dependency for access control.");
+        }
+      }
+      /** @var \Drupal\Core\Entity\EntityInterface $dependency */
+      $access = $access->andIf($dependency->access($operation, $account, TRUE));
+    }
+    return $access;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function checkCreateAccess(AccountInterface $account, array $context, $entity_bundle = NULL) {
+    return AccessResult::allowedIfHasPermissions($account, [
+      'create ' . $entity_bundle . ' block content',
+      'access block library',
+    ])->orIf(AccessResult::allowedIfHasPermissions($account, [
+      'administer block content',
+    ]));
+  }
+
+}

src/BlockContentEvents.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Drupal\block_content;
+
+/**
+ * Defines events for the block_content module.
+ *
+ * @see \Drupal\block_content\Event\BlockContentGetDependencyEvent
+ *
+ * @internal
+ */
+final class BlockContentEvents {
+
+  /**
+   * Name of the event when getting the dependency of a non-reusable block.
+   *
+   * This event allows modules to provide a dependency for non-reusable block
+   * access if
+   * \Drupal\block_content\Access\DependentAccessInterface::getAccessDependency()
+   * did not return a dependency during access checking.
+   *
+   * @Event
+   *
+   * @see \Drupal\block_content\Event\BlockContentGetDependencyEvent
+   * @see \Drupal\block_content\BlockContentAccessControlHandler::checkAccess()
+   *
+   * @var string
+   */
+  const BLOCK_CONTENT_GET_DEPENDENCY = 'block_content.get_dependency';
+
+}

src/BlockContentForm.php

@@ -0,0 +1,134 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Entity\ContentEntityForm;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Form handler for the content block edit forms.
+ *
+ * @internal
+ */
+class BlockContentForm extends ContentEntityForm {
+
+  /**
+   * The block content entity.
+   *
+   * @var \Drupal\block_content\BlockContentInterface
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(array $form, FormStateInterface $form_state) {
+    $block = $this->entity;
+    $form = parent::form($form, $form_state);
+
+    if ($this->operation == 'edit') {
+      $form['#title'] = $this->t('Edit content block %label', ['%label' => $block->label()]);
+    }
+    // Override the default CSS class name, since the user-defined content block
+    // type name in 'TYPE-block-form' potentially clashes with third-party class
+    // names.
+    $form['#attributes']['class'][0] = 'block-' . Html::getClass($block->bundle()) . '-form';
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function actions(array $form, FormStateInterface $form_state): array {
+    $element = parent::actions($form, $form_state);
+
+    if ($this->getRequest()->query->has('theme')) {
+      $element['submit']['#value'] = $this->t('Save and configure');
+    }
+
+    if ($this->currentUser()->hasPermission('administer blocks') && !$this->getRequest()->query->has('theme') && $this->entity->isNew()) {
+      $element['configure_block'] = [
+        '#type' => 'submit',
+        '#value' => $this->t('Save and configure'),
+        '#weight' => 20,
+        '#submit' => array_merge($element['submit']['#submit'], ['::configureBlock']),
+      ];
+    }
+
+    return $element;
+  }
+
+  /**
+   * Form submission handler for the 'configureBlock' action.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   */
+  public function configureBlock(array $form, FormStateInterface $form_state): void {
+    $block = $this->entity;
+    if (!$theme = $block->getTheme()) {
+      $theme = $this->config('system.theme')->get('default');
+    }
+    $form_state->setRedirect(
+      'block.admin_add',
+      [
+        'plugin_id' => 'block_content:' . $block->uuid(),
+        'theme' => $theme,
+      ]
+    );
+    $form_state->setIgnoreDestination();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function save(array $form, FormStateInterface $form_state) {
+    $block = $this->entity;
+
+    $insert = $block->isNew();
+    $block->save();
+    $context = ['@type' => $block->bundle(), '%info' => $block->label()];
+    $logger = $this->logger('block_content');
+    $block_type = $this->getBundleEntity();
+    $t_args = ['@type' => $block_type->label(), '%info' => $block->label()];
+
+    if ($insert) {
+      $logger->info('@type: added %info.', $context);
+      $this->messenger()->addStatus($this->t('@type %info has been created.', $t_args));
+    }
+    else {
+      $logger->info('@type: updated %info.', $context);
+      $this->messenger()->addStatus($this->t('@type %info has been updated.', $t_args));
+    }
+
+    if ($block->id()) {
+      $form_state->setValue('id', $block->id());
+      $form_state->set('id', $block->id());
+      $theme = $block->getTheme();
+      if ($insert && $theme) {
+        $form_state->setRedirect(
+          'block.admin_add',
+          [
+            'plugin_id' => 'block_content:' . $block->uuid(),
+            'theme' => $theme,
+            'region' => $this->getRequest()->query->getString('region'),
+          ]
+        );
+      }
+      else {
+        $form_state->setRedirectUrl($block->toUrl('collection'));
+      }
+    }
+    else {
+      // In the unlikely case something went wrong on save, the block will be
+      // rebuilt and block form redisplayed.
+      $this->messenger()->addError($this->t('The block could not be saved.'));
+      $form_state->setRebuild();
+    }
+  }
+
+}

src/BlockContentInterface.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\block_content\Access\RefinableDependentAccessInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Entity\EntityChangedInterface;
+use Drupal\Core\Entity\EntityPublishedInterface;
+use Drupal\Core\Entity\RevisionLogInterface;
+
+/**
+ * Provides an interface defining a content block entity.
+ */
+interface BlockContentInterface extends ContentEntityInterface, EntityChangedInterface, RevisionLogInterface, EntityPublishedInterface, RefinableDependentAccessInterface {
+
+  /**
+   * Sets the block description.
+   *
+   * @param string $info
+   *   The block description.
+   *
+   * @return $this
+   *   The class instance that this method is called on.
+   */
+  public function setInfo($info);
+
+  /**
+   * Determines if the block is reusable or not.
+   *
+   * @return bool
+   *   Returns TRUE if reusable and FALSE otherwise.
+   */
+  public function isReusable();
+
+  /**
+   * Sets the block to be reusable.
+   *
+   * @return $this
+   */
+  public function setReusable();
+
+  /**
+   * Sets the block to be non-reusable.
+   *
+   * @return $this
+   */
+  public function setNonReusable();
+
+  /**
+   * Sets the theme value.
+   *
+   * When creating a new block content block from the block library, the user is
+   * redirected to the configure form for that block in the given theme. The
+   * theme is stored against the block when the block content add form is shown.
+   *
+   * @param string $theme
+   *   The theme name.
+   *
+   * @return $this
+   *   The class instance that this method is called on.
+   */
+  public function setTheme($theme);
+
+  /**
+   * Gets the theme value.
+   *
+   * When creating a new block content block from the block library, the user is
+   * redirected to the configure form for that block in the given theme. The
+   * theme is stored against the block when the block content add form is shown.
+   *
+   * @return string
+   *   The theme name.
+   */
+  public function getTheme();
+
+  /**
+   * Gets the configured instances of this content block.
+   *
+   * @return array
+   *   Array of Drupal\block\Core\Plugin\Entity\Block entities.
+   */
+  public function getInstances();
+
+}

src/BlockContentListBuilder.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityListBuilder;
+
+/**
+ * Defines a class to build a listing of content block entities.
+ *
+ * @see \Drupal\block_content\Entity\BlockContent
+ */
+class BlockContentListBuilder extends EntityListBuilder {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildHeader() {
+    $header['label'] = $this->t('Block description');
+    return $header + parent::buildHeader();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildRow(EntityInterface $entity) {
+    $row['label'] = $entity->label();
+    return $row + parent::buildRow($entity);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEntityIds() {
+    $request = \Drupal::request();
+    $query = $this->getStorage()->getQuery()->accessCheck(TRUE);
+    $foo = $request->get('foo') ?? 0;
+    if ($foo) {
+      $query->condition('label', "%" . $foo . "%", 'LIKE');
+    }
+    $query->sort($this->entityType->getKey('id'));
+    $query->condition('reusable', TRUE);
+    // Only add the pager if a limit is specified.
+    if ($this->limit) {
+      $query->pager($this->limit);
+    }
+    return $query->execute();
+  }
+
+
+  /**
+   * {@inheritdoc}
+   */
+  public function render() {
+    $build['form'] = \Drupal::formBuilder()->getForm('Drupal\block_content\Form\BlockContentListFiltersForm');
+    $build += parent::render();
+    return $build;
+  }
+
+}

src/BlockContentPermissions.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\Entity\BundlePermissionHandlerTrait;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provide dynamic permissions for blocks of different types.
+ */
+class BlockContentPermissions implements ContainerInjectionInterface {
+
+  use StringTranslationTrait;
+  use BundlePermissionHandlerTrait;
+
+  /**
+   * Constructs a BlockContentPermissions instance.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   *   Entity type manager.
+   */
+  public function __construct(
+    protected EntityTypeManagerInterface $entityTypeManager,
+  ) {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('entity_type.manager'),
+    );
+  }
+
+  /**
+   * Build permissions for each block type.
+   *
+   * @return array
+   *   The block type permissions.
+   */
+  public function blockTypePermissions() {
+    return $this->generatePermissions($this->entityTypeManager->getStorage('block_content_type')->loadMultiple(), [$this, 'buildPermissions']);
+  }
+
+  /**
+   * Return all the permissions available for a block type.
+   *
+   * @param \Drupal\block_content\Entity\BlockContentType $type
+   *   The block type.
+   *
+   * @return array
+   *   Permissions available for the given block type.
+   */
+  protected function buildPermissions(BlockContentType $type) {
+    $type_id = $type->id();
+    $type_params = ['%type_name' => $type->label()];
+    return [
+      "create $type_id block content" => [
+        'title' => $this->t('%type_name: Create new content block', $type_params),
+      ],
+      "edit any $type_id block content" => [
+        'title' => $this->t('%type_name: Edit content block', $type_params),
+      ],
+      "delete any $type_id block content" => [
+        'title' => $this->t('%type_name: Delete content block', $type_params),
+      ],
+      "view any $type_id block content history" => [
+        'title' => $this->t('%type_name: View content block history pages', $type_params),
+      ],
+      "revert any $type_id block content revisions" => [
+        'title' => $this->t('%type_name: Revert content block revisions', $type_params),
+      ],
+      "delete any $type_id block content revisions" => [
+        'title' => $this->t('%type_name: Delete content block revisions', $type_params),
+      ],
+    ];
+  }
+
+}

src/BlockContentStorageSchema.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+
+/**
+ * Defines the block content schema handler.
+ */
+class BlockContentStorageSchema extends SqlContentEntityStorageSchema {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSharedTableFieldSchema(FieldStorageDefinitionInterface $storage_definition, $table_name, array $column_mapping): array {
+    $schema = parent::getSharedTableFieldSchema($storage_definition, $table_name, $column_mapping);
+    $field_name = $storage_definition->getName();
+
+    if ($table_name === $this->storage->getDataTable() && $field_name === 'reusable') {
+      $this->addSharedTableFieldIndex($storage_definition, $schema);
+    }
+
+    return $schema;
+  }
+
+}

src/BlockContentTranslationHandler.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\content_translation\ContentTranslationHandler;
+
+/**
+ * Defines the translation handler for content blocks.
+ */
+class BlockContentTranslationHandler extends ContentTranslationHandler {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function entityFormTitle(EntityInterface $entity) {
+    $block_type = BlockContentType::load($entity->bundle());
+    return $this->t('<em>Edit @type</em> @title', ['@type' => $block_type->label(), '@title' => $entity->label()]);
+  }
+
+}

src/BlockContentTypeForm.php

@@ -0,0 +1,128 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Entity\BundleEntityFormBase;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\language\Entity\ContentLanguageSettings;
+
+/**
+ * The block content type entity form.
+ *
+ * @internal
+ */
+class BlockContentTypeForm extends BundleEntityFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(array $form, FormStateInterface $form_state) {
+    $form = parent::form($form, $form_state);
+
+    /** @var \Drupal\block_content\BlockContentTypeInterface $block_type */
+    $block_type = $this->entity;
+
+    if ($this->operation == 'add') {
+      $form['#title'] = $this->t('Add block type');
+    }
+    else {
+      $form['#title'] = $this->t('Edit %label block type', ['%label' => $block_type->label()]);
+    }
+
+    $form['label'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Label'),
+      '#maxlength' => 255,
+      '#default_value' => $block_type->label(),
+      '#description' => $this->t("The human-readable name for this block type, displayed on the <em>Block types</em> page."),
+      '#required' => TRUE,
+    ];
+    $form['id'] = [
+      '#type' => 'machine_name',
+      '#default_value' => $block_type->id(),
+      '#machine_name' => [
+        'exists' => '\Drupal\block_content\Entity\BlockContentType::load',
+      ],
+      '#description' => $this->t("Unique machine-readable name: lowercase letters, numbers, and underscores only."),
+      '#maxlength' => EntityTypeInterface::BUNDLE_MAX_LENGTH,
+    ];
+
+    $form['description'] = [
+      '#type' => 'textarea',
+      '#default_value' => $block_type->getDescription(),
+      '#description' => $this->t('Displays on the <em>Block types</em> page.'),
+      '#title' => $this->t('Description'),
+    ];
+
+    $form['revision'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Create new revision'),
+      '#default_value' => $block_type->shouldCreateNewRevision(),
+      '#description' => $this->t('Create a new revision by default for this block type.'),
+    ];
+
+    if ($this->moduleHandler->moduleExists('language')) {
+      $form['language'] = [
+        '#type' => 'details',
+        '#title' => $this->t('Language settings'),
+        '#group' => 'additional_settings',
+      ];
+
+      $language_configuration = ContentLanguageSettings::loadByEntityTypeBundle('block_content', $block_type->id());
+      $form['language']['language_configuration'] = [
+        '#type' => 'language_configuration',
+        '#entity_information' => [
+          'entity_type' => 'block_content',
+          'bundle' => $block_type->id(),
+        ],
+        '#default_value' => $language_configuration,
+      ];
+
+      $form['#submit'][] = 'language_configuration_element_submit';
+    }
+
+    $form['actions'] = ['#type' => 'actions'];
+    $form['actions']['submit'] = [
+      '#type' => 'submit',
+      '#value' => $this->t('Save'),
+    ];
+
+    return $this->protectBundleIdElement($form);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function copyFormValuesToEntity(EntityInterface $entity, array $form, FormStateInterface $form_state) {
+    // An empty description violates config schema.
+    if (trim($form_state->getValue('description', '')) === '') {
+      $form_state->unsetValue('description');
+    }
+    parent::copyFormValuesToEntity($entity, $form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function save(array $form, FormStateInterface $form_state) {
+    $block_type = $this->entity;
+    $status = $block_type->save();
+
+    $edit_link = $this->entity->toLink($this->t('Edit'), 'edit-form')->toString();
+    $logger = $this->logger('block_content');
+    if ($status == SAVED_UPDATED) {
+      $this->messenger()->addStatus($this->t('Block type %label has been updated.', ['%label' => $block_type->label()]));
+      $logger->notice('Block type %label has been updated.', ['%label' => $block_type->label(), 'link' => $edit_link]);
+    }
+    else {
+      block_content_add_body_field($block_type->id());
+      $this->messenger()->addStatus($this->t('Block type %label has been added.', ['%label' => $block_type->label()]));
+      $logger->notice('Block type %label has been added.', ['%label' => $block_type->label(), 'link' => $edit_link]);
+    }
+
+    $form_state->setRedirectUrl($this->entity->toUrl('collection'));
+  }
+
+}

src/BlockContentTypeInterface.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
+use Drupal\Core\Entity\RevisionableEntityBundleInterface;
+
+/**
+ * Provides an interface defining a block type entity.
+ */
+interface BlockContentTypeInterface extends ConfigEntityInterface, RevisionableEntityBundleInterface {
+
+  /**
+   * Returns the description of the block type.
+   *
+   * @return string
+   *   The description of the type of this block.
+   */
+  public function getDescription();
+
+}

src/BlockContentTypeListBuilder.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Defines a class to build a listing of block type entities.
+ *
+ * @see \Drupal\block_content\Entity\BlockContentType
+ */
+class BlockContentTypeListBuilder extends ConfigEntityListBuilder {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDefaultOperations(EntityInterface $entity) {
+    $operations = parent::getDefaultOperations($entity);
+    // Place the edit operation after the operations added by field_ui.module
+    // which have the weights 15, 20, 25.
+    if (isset($operations['edit'])) {
+      $operations['edit']['weight'] = 30;
+    }
+    return $operations;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildHeader() {
+    $header['type'] = $this->t('Block type');
+    $header['description'] = $this->t('Description');
+    return $header + parent::buildHeader();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildRow(EntityInterface $entity) {
+    $row['type'] = $entity->toLink(NULL, 'edit-form')->toString();
+    $row['description']['data']['#markup'] = $entity->getDescription();
+    return $row + parent::buildRow($entity);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getTitle() {
+    return $this->t('Block types');
+  }
+
+}

src/BlockContentUuidLookup.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Cache\CacheCollector;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Lock\LockBackendInterface;
+
+/**
+ * A cache collector that caches IDs for block_content UUIDs.
+ *
+ * As block_content entities are used as block plugin derivatives, it is a
+ * fairly safe limitation that there are not hundreds of them, a site will
+ * likely run into problems with too many block content entities in other places
+ * than a cache that only stores UUID's and IDs. The same assumption is not true
+ * for other content entities.
+ *
+ * @internal
+ */
+class BlockContentUuidLookup extends CacheCollector {
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * Constructs a BlockContentUuidLookup instance.
+   *
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache backend.
+   * @param \Drupal\Core\Lock\LockBackendInterface $lock
+   *   The lock backend.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   */
+  public function __construct(CacheBackendInterface $cache, LockBackendInterface $lock, EntityTypeManagerInterface $entity_type_manager) {
+    parent::__construct('block_content_uuid', $cache, $lock);
+    $this->entityTypeManager = $entity_type_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function resolveCacheMiss($key) {
+    $ids = $this->entityTypeManager->getStorage('block_content')->getQuery()
+      ->accessCheck(FALSE)
+      ->condition('uuid', $key)
+      ->execute();
+
+    // Only cache if there is a match, otherwise creating new entities would
+    // require to invalidate the cache.
+    $id = reset($ids);
+    if ($id) {
+      $this->storage[$key] = $id;
+      $this->persist($key);
+    }
+    return $id;
+  }
+
+}

src/BlockContentViewBuilder.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityViewBuilder;
+
+/**
+ * View builder handler for content blocks.
+ *
+ * Note: Content blocks (block_content entities) are not designed to be displayed
+ * outside of blocks! This BlockContentViewBuilder class is designed to be used
+ * by \Drupal\block_content\Plugin\Block\BlockContentBlock::build() and by
+ * nothing else.
+ *
+ * @see \Drupal\block_content\Plugin\Block\BlockContentBlock
+ */
+class BlockContentViewBuilder extends EntityViewBuilder {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function view(EntityInterface $entity, $view_mode = 'full', $langcode = NULL) {
+    return $this->viewMultiple([$entity], $view_mode, $langcode)[0];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewMultiple(array $entities = [], $view_mode = 'full', $langcode = NULL) {
+    $build_list = parent::viewMultiple($entities, $view_mode, $langcode);
+    // Apply the buildMultiple() #pre_render callback immediately, to make
+    // bubbling of attributes and contextual links to the actual block work.
+    // @see \Drupal\block\BlockViewBuilder::buildBlock()
+    unset($build_list['#pre_render'][0]);
+    return $this->buildMultiple($build_list);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getBuildDefaults(EntityInterface $entity, $view_mode) {
+    $build = parent::getBuildDefaults($entity, $view_mode);
+    // The content block will be rendered in the wrapped block template already
+    // and thus has no entity template itself.
+    unset($build['#theme']);
+    return $build;
+  }
+
+}

src/BlockContentViewsData.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\views\EntityViewsData;
+
+/**
+ * Provides the views data for the block_content entity type.
+ */
+class BlockContentViewsData extends EntityViewsData {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getViewsData() {
+
+    $data = parent::getViewsData();
+
+    $data['block_content_field_data']['id']['field']['id'] = 'field';
+
+    $data['block_content_field_data']['info']['field']['id'] = 'field';
+    $data['block_content_field_data']['info']['field']['link_to_entity default'] = TRUE;
+
+    $data['block_content_field_data']['type']['field']['id'] = 'field';
+
+    $data['block_content_field_data']['table']['wizard_id'] = 'block_content';
+
+    $data['block_content']['block_content_listing_empty'] = [
+      'title' => $this->t('Empty block library behavior'),
+      'help' => $this->t('Provides a link to add a new block.'),
+      'area' => [
+        'id' => 'block_content_listing_empty',
+      ],
+    ];
+    // Advertise this table as a possible base table.
+    $data['block_content_field_revision']['table']['base']['help'] = $this->t('Block Content revision is a history of changes to block content.');
+    $data['block_content_field_revision']['table']['base']['defaults']['title'] = 'info';
+
+    return $data;
+  }
+
+}

src/BlockTypeAccessControlHandler.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Drupal\block_content;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Entity\EntityAccessControlHandler;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Defines the access control handler for the "Block Type" entity type.
+ *
+ * @see \Drupal\block_content\Entity\BlockContentType
+ */
+class BlockTypeAccessControlHandler extends EntityAccessControlHandler {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $viewLabelOperation = TRUE;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
+    if ($operation === 'view label') {
+      return AccessResult::allowedIfHasPermission($account, 'access block library')
+        ->orIf(parent::checkAccess($entity, $operation, $account));
+    }
+    return parent::checkAccess($entity, $operation, $account);
+  }
+
+}

src/Controller/BlockContentController.php

@@ -0,0 +1,239 @@
+<?php
+
+namespace Drupal\block_content\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Routing\PathChangedHelper;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\block_content\BlockContentInterface;
+use Drupal\block_content\BlockContentTypeInterface;
+use Drupal\Core\Extension\ThemeHandlerInterface;
+use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+
+class BlockContentController extends ControllerBase {
+
+  /**
+   * The content block storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $blockContentStorage;
+
+  /**
+   * The content block type storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $blockContentTypeStorage;
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   */
+  protected $themeHandler;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    $entity_type_manager = $container->get('entity_type.manager');
+    return new static(
+      $entity_type_manager->getStorage('block_content'),
+      $entity_type_manager->getStorage('block_content_type'),
+      $container->get('theme_handler')
+    );
+  }
+
+  /**
+   * Constructs a BlockContent object.
+   *
+   * @param \Drupal\Core\Entity\EntityStorageInterface $block_content_storage
+   *   The content block storage.
+   * @param \Drupal\Core\Entity\EntityStorageInterface $block_content_type_storage
+   *   The block type storage.
+   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
+   *   The theme handler.
+   */
+  public function __construct(EntityStorageInterface $block_content_storage, EntityStorageInterface $block_content_type_storage, ThemeHandlerInterface $theme_handler) {
+    $this->blockContentStorage = $block_content_storage;
+    $this->blockContentTypeStorage = $block_content_type_storage;
+    $this->themeHandler = $theme_handler;
+  }
+
+  /**
+   * Displays add content block links for available types.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request object.
+   *
+   * @return array
+   *   A render array for a list of the block types that can be added or
+   *   if there is only one block type defined for the site, the function
+   *   returns the content block add page for that block type.
+   */
+  public function add(Request $request) {
+    // @todo deprecate see https://www.drupal.org/project/drupal/issues/3346394.
+    $types = [];
+    // Only use block types the user has access to.
+    foreach ($this->blockContentTypeStorage->loadMultiple() as $type) {
+      $access = $this->entityTypeManager()->getAccessControlHandler('block_content')->createAccess($type->id(), NULL, [], TRUE);
+      if ($access->isAllowed()) {
+        $types[$type->id()] = $type;
+      }
+    }
+    uasort($types, [$this->blockContentTypeStorage->getEntityType()->getClass(), 'sort']);
+    if ($types && count($types) == 1) {
+      $type = reset($types);
+      return $this->addForm($type, $request);
+    }
+    if (count($types) === 0) {
+      return [
+        '#markup' => $this->t('You have not created any block types yet. Go to the <a href=":url">block type creation page</a> to add a new block type.', [
+          ':url' => Url::fromRoute('block_content.type_add')->toString(),
+        ]),
+      ];
+    }
+
+    return ['#theme' => 'block_content_add_list', '#content' => $types];
+  }
+
+  /**
+   * Presents the content block creation form.
+   *
+   * @param \Drupal\block_content\BlockContentTypeInterface $block_content_type
+   *   The block type to add.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request object.
+   *
+   * @return array
+   *   A form array as expected by
+   *   \Drupal\Core\Render\RendererInterface::render().
+   */
+  public function addForm(BlockContentTypeInterface $block_content_type, Request $request) {
+    $block = $this->blockContentStorage->create([
+      'type' => $block_content_type->id(),
+    ]);
+    if (($theme = $request->query->get('theme')) && in_array($theme, array_keys($this->themeHandler->listInfo()))) {
+      // We have navigated to this page from the block library and will keep track
+      // of the theme for redirecting the user to the configuration page for the
+      // newly created block in the given theme.
+      $block->setTheme($theme);
+    }
+    return $this->entityFormBuilder()->getForm($block);
+  }
+
+  /**
+   * Provides the page title for this controller.
+   *
+   * @param \Drupal\block_content\BlockContentTypeInterface $block_content_type
+   *   The block type being added.
+   *
+   * @return string
+   *   The page title.
+   */
+  public function getAddFormTitle(BlockContentTypeInterface $block_content_type) {
+    return $this->t('Add %type content block', ['%type' => $block_content_type->label()]);
+  }
+
+  /**
+   * Provides a redirect to the list of block types.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   A route match object, used for the route name and the parameters.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request object.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse
+   *
+   * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
+   *   /admin/structure/block-content directly instead of
+   *   /admin/structure/block/block-content/types.
+   *
+   * @see https://www.drupal.org/node/3320855
+   */
+  public function blockContentTypeRedirect(RouteMatchInterface $route_match, Request $request): RedirectResponse {
+    @trigger_error('The path /admin/structure/block/block-content/types is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/structure/block-content. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
+    $helper = new PathChangedHelper($route_match, $request);
+    $params = [
+      '%old_path' => $helper->oldPath(),
+      '%new_path' => $helper->newPath(),
+      '%change_record' => 'https://www.drupal.org/node/3320855',
+    ];
+    $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
+    $this->messenger()->addWarning($warning_message);
+    $this->getLogger('block_content')->warning('A user was redirected from %old_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
+
+    return $helper->redirect();
+  }
+
+  /**
+   * Provides a redirect to the content block library.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   A route match object, used for the route name and the parameters.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request object.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse
+   *
+   * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
+   *   /admin/content/block directly instead of
+   *   /admin/structure/block/block-content.
+   *
+   * @see https://www.drupal.org/node/3320855
+   */
+  public function blockLibraryRedirect(RouteMatchInterface $route_match, Request $request) {
+    @trigger_error('The path /admin/structure/block/block-content is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
+    $helper = new PathChangedHelper($route_match, $request);
+    $params = [
+      '%old_path' => $helper->oldPath(),
+      '%new_path' => $helper->newPath(),
+      '%change_record' => 'https://www.drupal.org/node/3320855',
+    ];
+    $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
+    $this->messenger()->addWarning($warning_message);
+    $this->getLogger('block_content')
+      ->warning('A user was redirected from %old_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
+
+    return $helper->redirect();
+  }
+
+  /**
+   * Provides a redirect to block edit page.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   A route match object, used for the route name and the parameters.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request object.
+   * @param Drupal\block_content\BlockContentInterface $block_content
+   *   The block to be edited.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse
+   *
+   * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
+   *   /admin/content/block/{block_content} directly instead of
+   *   /block/{block_content}.
+   *
+   * @see https://www.drupal.org/node/3320855
+   */
+  public function editRedirect(RouteMatchInterface $route_match, Request $request, BlockContentInterface $block_content): RedirectResponse {
+    @trigger_error('The path /block/{block_content} is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block/{block_content}. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
+    $helper = new PathChangedHelper($route_match, $request);
+    $params = [
+      '%old_path' => $helper->oldPath(),
+      '%new_path' => $helper->newPath(),
+      '%change_record' => 'https://www.drupal.org/node/3320855',
+    ];
+    $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
+    $this->messenger()->addWarning($warning_message);
+    $this->getLogger('block_content')->warning('A user was redirected from %old_path to %new_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
+
+    return $helper->redirect();
+  }
+
+}

src/Entity/BlockContent.php

@@ -0,0 +1,274 @@
+<?php
+
+namespace Drupal\block_content\Entity;
+
+use Drupal\block_content\Access\RefinableDependentAccessTrait;
+use Drupal\Core\Entity\EditorialContentEntityBase;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\block_content\BlockContentInterface;
+
+/**
+ * Defines the content block entity class.
+ *
+ * @ContentEntityType(
+ *   id = "block_content",
+ *   label = @Translation("Content block"),
+ *   label_collection = @Translation("Content blocks"),
+ *   label_singular = @Translation("content block"),
+ *   label_plural = @Translation("content blocks"),
+ *   label_count = @PluralTranslation(
+ *     singular = "@count content block",
+ *     plural = "@count content blocks",
+ *   ),
+ *   bundle_label = @Translation("Block type"),
+ *   handlers = {
+ *     "storage" = "Drupal\Core\Entity\Sql\SqlContentEntityStorage",
+ *     "storage_schema" = "Drupal\block_content\BlockContentStorageSchema",
+ *     "access" = "Drupal\block_content\BlockContentAccessControlHandler",
+ *     "list_builder" = "Drupal\block_content\BlockContentListBuilder",
+ *     "view_builder" = "Drupal\block_content\BlockContentViewBuilder",
+ *     "views_data" = "Drupal\block_content\BlockContentViewsData",
+ *     "form" = {
+ *       "add" = "Drupal\block_content\BlockContentForm",
+ *       "edit" = "Drupal\block_content\BlockContentForm",
+ *       "delete" = "Drupal\block_content\Form\BlockContentDeleteForm",
+ *       "default" = "Drupal\block_content\BlockContentForm",
+ *       "revision-delete" = \Drupal\Core\Entity\Form\RevisionDeleteForm::class,
+ *       "revision-revert" = \Drupal\Core\Entity\Form\RevisionRevertForm::class,
+ *     },
+ *     "route_provider" = {
+ *       "revision" = \Drupal\Core\Entity\Routing\RevisionHtmlRouteProvider::class,
+ *     },
+ *     "translation" = "Drupal\block_content\BlockContentTranslationHandler"
+ *   },
+ *   admin_permission = "administer block content",
+ *   collection_permission = "access block library",
+ *   base_table = "block_content",
+ *   revision_table = "block_content_revision",
+ *   data_table = "block_content_field_data",
+ *   revision_data_table = "block_content_field_revision",
+ *   show_revision_ui = TRUE,
+ *   links = {
+ *     "canonical" = "/admin/content/block/{block_content}",
+ *     "delete-form" = "/admin/content/block/{block_content}/delete",
+ *     "edit-form" = "/admin/content/block/{block_content}",
+ *     "collection" = "/admin/content/block",
+ *     "create" = "/block",
+ *     "revision-delete-form" = "/admin/content/block/{block_content}/revision/{block_content_revision}/delete",
+ *     "revision-revert-form" = "/admin/content/block/{block_content}/revision/{block_content_revision}/revert",
+ *     "version-history" = "/admin/content/block/{block_content}/revisions",
+ *   },
+ *   translatable = TRUE,
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "revision" = "revision_id",
+ *     "bundle" = "type",
+ *     "label" = "info",
+ *     "langcode" = "langcode",
+ *     "uuid" = "uuid",
+ *     "published" = "status",
+ *   },
+ *   revision_metadata_keys = {
+ *     "revision_user" = "revision_user",
+ *     "revision_created" = "revision_created",
+ *     "revision_log_message" = "revision_log"
+ *   },
+ *   bundle_entity_type = "block_content_type",
+ *   field_ui_base_route = "entity.block_content_type.edit_form",
+ *   render_cache = FALSE,
+ * )
+ *
+ * Note that render caching of block_content entities is disabled because they
+ * are always rendered as blocks, and blocks already have their own render
+ * caching.
+ * See https://www.drupal.org/node/2284917#comment-9132521 for more information.
+ */
+class BlockContent extends EditorialContentEntityBase implements BlockContentInterface {
+
+  use RefinableDependentAccessTrait;
+
+  /**
+   * The theme the block is being created in.
+   *
+   * When creating a new content block from the block library, the user is
+   * redirected to the configure form for that block in the given theme. The
+   * theme is stored against the block when the content block add form is shown.
+   *
+   * @var string
+   */
+  protected $theme;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function createDuplicate() {
+    $duplicate = parent::createDuplicate();
+    $duplicate->revision_id->value = NULL;
+    $duplicate->id->value = NULL;
+    return $duplicate;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setTheme($theme) {
+    $this->theme = $theme;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTheme() {
+    return $this->theme;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
+    parent::postSave($storage, $update);
+    if ($this->isReusable() || (isset($this->original) && $this->original->isReusable())) {
+      static::invalidateBlockPluginCache();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function preDelete(EntityStorageInterface $storage, array $entities) {
+    parent::preDelete($storage, $entities);
+
+    /** @var \Drupal\block_content\BlockContentInterface $block */
+    foreach ($entities as $block) {
+      foreach ($block->getInstances() as $instance) {
+        $instance->delete();
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function postDelete(EntityStorageInterface $storage, array $entities) {
+    parent::postDelete($storage, $entities);
+    /** @var \Drupal\block_content\BlockContentInterface $block */
+    foreach ($entities as $block) {
+      if ($block->isReusable()) {
+        // If any deleted blocks are reusable clear the block cache.
+        static::invalidateBlockPluginCache();
+        return;
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getInstances() {
+    return \Drupal::entityTypeManager()->getStorage('block')->loadByProperties(['plugin' => 'block_content:' . $this->uuid()]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function preSaveRevision(EntityStorageInterface $storage, \stdClass $record) {
+    parent::preSaveRevision($storage, $record);
+
+    if (!$this->isNewRevision() && isset($this->original) && empty($record->revision_log_message)) {
+      // If we are updating an existing block_content without adding a new
+      // revision and the user did not supply a revision log, keep the existing
+      // one.
+      $record->revision_log = $this->original->getRevisionLogMessage();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
+    /** @var \Drupal\Core\Field\BaseFieldDefinition[] $fields */
+    $fields = parent::baseFieldDefinitions($entity_type);
+
+    $fields['id']->setLabel(t('Content block ID'))
+      ->setDescription(t('The content block ID.'));
+
+    $fields['uuid']->setDescription(t('The content block UUID.'));
+
+    $fields['revision_id']->setDescription(t('The revision ID.'));
+
+    $fields['langcode']->setDescription(t('The content block language code.'));
+
+    $fields['type']->setLabel(t('Block type'))
+      ->setDescription(t('The block type.'));
+
+    $fields['revision_log']->setDescription(t('The log entry explaining the changes in this revision.'));
+
+    $fields['info'] = BaseFieldDefinition::create('string')
+      ->setLabel(t('Block description'))
+      ->setDescription(t('A brief description of your block.'))
+      ->setRevisionable(TRUE)
+      ->setTranslatable(TRUE)
+      ->setRequired(TRUE)
+      ->setDisplayOptions('form', [
+        'type' => 'string_textfield',
+        'weight' => -5,
+      ])
+      ->setDisplayConfigurable('form', TRUE);
+
+    $fields['changed'] = BaseFieldDefinition::create('changed')
+      ->setLabel(t('Changed'))
+      ->setDescription(t('The time that the content block was last edited.'))
+      ->setTranslatable(TRUE)
+      ->setRevisionable(TRUE);
+
+    $fields['reusable'] = BaseFieldDefinition::create('boolean')
+      ->setLabel(t('Reusable'))
+      ->setDescription(t('A boolean indicating whether this block is reusable.'))
+      ->setTranslatable(FALSE)
+      ->setRevisionable(FALSE)
+      ->setDefaultValue(TRUE);
+
+    return $fields;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setInfo($info) {
+    $this->set('info', $info);
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isReusable() {
+    return (bool) $this->get('reusable')->value;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setReusable() {
+    return $this->set('reusable', TRUE);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setNonReusable() {
+    return $this->set('reusable', FALSE);
+  }
+
+  /**
+   * Invalidates the block plugin cache after changes and deletions.
+   */
+  protected static function invalidateBlockPluginCache() {
+    // Invalidate the block cache to update content block-based derivatives.
+    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
+  }
+
+}

src/Entity/BlockContentType.php

@@ -0,0 +1,100 @@
+<?php
+
+namespace Drupal\block_content\Entity;
+
+use Drupal\Core\Config\Entity\ConfigEntityBundleBase;
+use Drupal\block_content\BlockContentTypeInterface;
+
+/**
+ * Defines the block type entity.
+ *
+ * @ConfigEntityType(
+ *   id = "block_content_type",
+ *   label = @Translation("Block type"),
+ *   label_collection = @Translation("Block types"),
+ *   label_singular = @Translation("block type"),
+ *   label_plural = @Translation("block types"),
+ *   label_count = @PluralTranslation(
+ *     singular = "@count block type",
+ *     plural = "@count block types",
+ *   ),
+ *   handlers = {
+ *     "access" = "Drupal\block_content\BlockTypeAccessControlHandler",
+ *     "form" = {
+ *       "default" = "Drupal\block_content\BlockContentTypeForm",
+ *       "add" = "Drupal\block_content\BlockContentTypeForm",
+ *       "edit" = "Drupal\block_content\BlockContentTypeForm",
+ *       "delete" = "Drupal\block_content\Form\BlockContentTypeDeleteForm"
+ *     },
+ *     "route_provider" = {
+ *       "html" = "Drupal\Core\Entity\Routing\AdminHtmlRouteProvider",
+ *       "permissions" = "Drupal\user\Entity\EntityPermissionsRouteProvider",
+ *     },
+ *     "list_builder" = "Drupal\block_content\BlockContentTypeListBuilder"
+ *   },
+ *   admin_permission = "administer block types",
+ *   config_prefix = "type",
+ *   bundle_of = "block_content",
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "label" = "label"
+ *   },
+ *   links = {
+ *     "delete-form" = "/admin/structure/block-content/manage/{block_content_type}/delete",
+ *     "edit-form" = "/admin/structure/block-content/manage/{block_content_type}",
+ *     "entity-permissions-form" = "/admin/structure/block-content/manage/{block_content_type}/permissions",
+ *     "collection" = "/admin/structure/block-content",
+ *   },
+ *   config_export = {
+ *     "id",
+ *     "label",
+ *     "revision",
+ *     "description",
+ *   }
+ * )
+ */
+class BlockContentType extends ConfigEntityBundleBase implements BlockContentTypeInterface {
+
+  /**
+   * The block type ID.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The block type label.
+   *
+   * @var string
+   */
+  protected $label;
+
+  /**
+   * The default revision setting for content blocks of this type.
+   *
+   * @var bool
+   */
+  protected $revision = FALSE;
+
+  /**
+   * The description of the block type.
+   *
+   * @var string|null
+   */
+  protected $description = NULL;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDescription() {
+    return $this->description ?? '';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function shouldCreateNewRevision() {
+    return $this->revision;
+  }
+
+}

src/Event/BlockContentGetDependencyEvent.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace Drupal\block_content\Event;
+
+use Drupal\block_content\BlockContentInterface;
+use Drupal\Core\Access\AccessibleInterface;
+use Drupal\Component\EventDispatcher\Event;
+
+/**
+ * Block content event to allow setting an access dependency.
+ *
+ * @internal
+ */
+class BlockContentGetDependencyEvent extends Event {
+
+  /**
+   * The block content entity.
+   *
+   * @var \Drupal\block_content\BlockContentInterface
+   */
+  protected $blockContent;
+
+  /**
+   * The dependency.
+   *
+   * @var \Drupal\Core\Access\AccessibleInterface
+   */
+  protected $accessDependency;
+
+  /**
+   * BlockContentGetDependencyEvent constructor.
+   *
+   * @param \Drupal\block_content\BlockContentInterface $blockContent
+   *   The block content entity.
+   */
+  public function __construct(BlockContentInterface $blockContent) {
+    $this->blockContent = $blockContent;
+  }
+
+  /**
+   * Gets the block content entity.
+   *
+   * @return \Drupal\block_content\BlockContentInterface
+   *   The block content entity.
+   */
+  public function getBlockContentEntity() {
+    return $this->blockContent;
+  }
+
+  /**
+   * Gets the access dependency.
+   *
+   * @return \Drupal\Core\Access\AccessibleInterface
+   *   The access dependency.
+   */
+  public function getAccessDependency() {
+    return $this->accessDependency;
+  }
+
+  /**
+   * Sets the access dependency.
+   *
+   * @param \Drupal\Core\Access\AccessibleInterface $access_dependency
+   *   The access dependency.
+   */
+  public function setAccessDependency(AccessibleInterface $access_dependency) {
+    $this->accessDependency = $access_dependency;
+  }
+
+}

src/Form/BlockContentDeleteForm.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Drupal\block_content\Form;
+
+use Drupal\Core\Entity\ContentEntityDeleteForm;
+
+/**
+ * Provides a confirmation form for deleting a content block entity.
+ *
+ * @internal
+ */
+class BlockContentDeleteForm extends ContentEntityDeleteForm {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDescription() {
+    $instances = $this->entity->getInstances();
+    if (!empty($instances)) {
+      return $this->formatPlural(count($instances), 'This will also remove 1 placed block instance. This action cannot be undone.', 'This will also remove @count placed block instances. This action cannot be undone.');
+    }
+    return parent::getDescription();
+  }
+
+}

src/Form/BlockContentListFiltersForm.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace Drupal\block_content\Form;
+
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Form for filters on the blocks entity list page.
+ */
+class BlockContentListFiltersForm extends FormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'block_content_list_filters_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $request = \Drupal::request();
+    $form['filter'] = [
+      '#type' => 'container',
+      '#attributes' => [
+        'class' => ['form--inline', 'clearfix'],
+      ],
+    ];
+
+    $form['filter']['foo'] = [
+      '#type' => 'textfield',
+      '#title' => 'Search for block',
+      '#default_value' => $request->get('foo') ?? "",
+    ];
+
+    $form['actions']['wrapper'] = [
+      '#type' => 'container',
+      '#attributes' => ['class' => ['form-item']],
+    ];
+
+    $form['actions']['wrapper']['submit'] = [
+      '#type' => 'submit',
+      '#value' => 'Filter',
+    ];
+
+    if ($request->getQueryString()) {
+      $form['actions']['wrapper']['reset'] = [
+        '#type' => 'submit',
+        '#value' => 'Reset',
+        '#submit' => ['::resetForm'],
+      ];
+    }
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $query = [];
+
+    $foo = $form_state->getValue('foo') ?? 0;
+    if ($foo) {
+      $query['foo'] = $foo;
+    }
+
+    $form_state->setRedirect('entity.block_content.collection', $query);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function resetForm(array $form, FormStateInterface &$form_state) {
+    $form_state->setRedirect('entity.block_content.collection');
+  }
+
+}

src/Form/BlockContentTypeDeleteForm.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Drupal\block_content\Form;
+
+use Drupal\Core\Entity\EntityDeleteForm;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Provides a confirmation form for deleting a block type entity.
+ *
+ * @internal
+ */
+class BlockContentTypeDeleteForm extends EntityDeleteForm {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $block_count = $this->entityTypeManager->getStorage('block_content')->getQuery()
+      ->accessCheck(FALSE)
+      ->condition('type', $this->entity->id())
+      ->count()
+      ->execute();
+    if ($block_count) {
+      $caption = '<p>' . $this->formatPlural($block_count, '%label is used by 1 content block on your site. You can not remove this block type until you have removed all of the %label blocks.', '%label is used by @count content blocks on your site. You may not remove %label until you have removed all of the %label content blocks.', ['%label' => $this->entity->label()]) . '</p>';
+      $form['description'] = ['#markup' => $caption];
+      return $form;
+    }
+    else {
+      return parent::buildForm($form, $form_state);
+    }
+  }
+
+}

src/Plugin/Block/BlockContentBlock.php

@@ -0,0 +1,218 @@
+<?php
+
+namespace Drupal\block_content\Plugin\Block;
+
+use Drupal\block_content\BlockContentUuidLookup;
+use Drupal\block_content\Plugin\Derivative\BlockContent;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\Attribute\Block;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Block\BlockManagerInterface;
+use Drupal\Core\Entity\EntityDisplayRepositoryInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Routing\UrlGeneratorInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Defines a generic block type.
+ */
+#[Block(
+  id: "block_content",
+  admin_label: new TranslatableMarkup("Content block"),
+  category: new TranslatableMarkup("Content block"),
+  deriver: BlockContent::class
+)]
+class BlockContentBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The Plugin Block Manager.
+   *
+   * @var \Drupal\Core\Block\BlockManagerInterface
+   */
+  protected $blockManager;
+
+  /**
+   * The entity type manager service.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The Drupal account to use for checking for access to block.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $account;
+
+  /**
+   * The block content entity.
+   *
+   * @var \Drupal\block_content\BlockContentInterface
+   */
+  protected $blockContent;
+
+  /**
+   * The URL generator.
+   *
+   * @var \Drupal\Core\Routing\UrlGeneratorInterface
+   */
+  protected $urlGenerator;
+
+  /**
+   * The block content UUID lookup service.
+   *
+   * @var \Drupal\block_content\BlockContentUuidLookup
+   */
+  protected $uuidLookup;
+
+  /**
+   * The entity display repository.
+   *
+   * @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface
+   */
+  protected $entityDisplayRepository;
+
+  /**
+   * Constructs a new BlockContentBlock.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin ID for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Block\BlockManagerInterface $block_manager
+   *   The Plugin Block Manager.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager service.
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   The account for which view access should be checked.
+   * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
+   *   The URL generator.
+   * @param \Drupal\block_content\BlockContentUuidLookup $uuid_lookup
+   *   The block content UUID lookup service.
+   * @param \Drupal\Core\Entity\EntityDisplayRepositoryInterface $entity_display_repository
+   *   The entity display repository.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, BlockManagerInterface $block_manager, EntityTypeManagerInterface $entity_type_manager, AccountInterface $account, UrlGeneratorInterface $url_generator, BlockContentUuidLookup $uuid_lookup, EntityDisplayRepositoryInterface $entity_display_repository) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->blockManager = $block_manager;
+    $this->entityTypeManager = $entity_type_manager;
+    $this->account = $account;
+    $this->urlGenerator = $url_generator;
+    $this->uuidLookup = $uuid_lookup;
+    $this->entityDisplayRepository = $entity_display_repository;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('plugin.manager.block'),
+      $container->get('entity_type.manager'),
+      $container->get('current_user'),
+      $container->get('url_generator'),
+      $container->get('block_content.uuid_lookup'),
+      $container->get('entity_display.repository')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration() {
+    return [
+      'status' => TRUE,
+      'info' => '',
+      'view_mode' => 'full',
+    ];
+  }
+
+  /**
+   * Overrides \Drupal\Core\Block\BlockBase::blockForm().
+   *
+   * Adds body and description fields to the block configuration form.
+   */
+  public function blockForm($form, FormStateInterface $form_state) {
+    $block = $this->getEntity();
+    if (!$block) {
+      return $form;
+    }
+    $options = $this->entityDisplayRepository->getViewModeOptionsByBundle('block_content', $block->bundle());
+
+    $form['view_mode'] = [
+      '#type' => 'select',
+      '#options' => $options,
+      '#title' => $this->t('View mode'),
+      '#description' => $this->t('Output the block in this view mode.'),
+      '#default_value' => $this->configuration['view_mode'],
+      '#access' => (count($options) > 1),
+    ];
+    $form['title']['#description'] = $this->t('The title of the block as shown to the user.');
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function blockSubmit($form, FormStateInterface $form_state) {
+    // Invalidate the block cache to update content block-based derivatives.
+    $this->configuration['view_mode'] = $form_state->getValue('view_mode');
+    $this->blockManager->clearCachedDefinitions();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function blockAccess(AccountInterface $account) {
+    if ($this->getEntity()) {
+      return $this->getEntity()->access('view', $account, TRUE);
+    }
+    return AccessResult::forbidden();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    if ($block = $this->getEntity()) {
+      return $this->entityTypeManager->getViewBuilder($block->getEntityTypeId())->view($block, $this->configuration['view_mode']);
+    }
+    else {
+      return [
+        '#markup' => $this->t('Block with uuid %uuid does not exist. <a href=":url">Add content block</a>.', [
+          '%uuid' => $this->getDerivativeId(),
+          ':url' => $this->urlGenerator->generate('block_content.add_page'),
+        ]),
+        '#access' => $this->account->hasPermission('administer blocks'),
+      ];
+    }
+  }
+
+  /**
+   * Loads the block content entity of the block.
+   *
+   * @return \Drupal\block_content\BlockContentInterface|null
+   *   The block content entity.
+   */
+  protected function getEntity() {
+    if (!isset($this->blockContent)) {
+      $uuid = $this->getDerivativeId();
+      if ($id = $this->uuidLookup->get($uuid)) {
+        $this->blockContent = $this->entityTypeManager->getStorage('block_content')->load($id);
+      }
+    }
+    return $this->blockContent;
+  }
+
+}

src/Plugin/Derivative/BlockContent.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Drupal\block_content\Plugin\Derivative;
+
+use Drupal\Component\Plugin\Derivative\DeriverBase;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Retrieves block plugin definitions for all content blocks.
+ */
+class BlockContent extends DeriverBase implements ContainerDeriverInterface {
+
+  /**
+   * The content block storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $blockContentStorage;
+
+  /**
+   * Constructs a BlockContent object.
+   *
+   * @param \Drupal\Core\Entity\EntityStorageInterface $block_content_storage
+   *   The content block storage.
+   */
+  public function __construct(EntityStorageInterface $block_content_storage) {
+    $this->blockContentStorage = $block_content_storage;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, $base_plugin_id) {
+    $entity_type_manager = $container->get('entity_type.manager');
+    return new static(
+      $entity_type_manager->getStorage('block_content')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDerivativeDefinitions($base_plugin_definition) {
+    $block_contents = $this->blockContentStorage->loadByProperties(['reusable' => TRUE]);
+    // Reset the discovered definitions.
+    $this->derivatives = [];
+    /** @var \Drupal\block_content\Entity\BlockContent $block_content */
+    foreach ($block_contents as $block_content) {
+      $this->derivatives[$block_content->uuid()] = $base_plugin_definition;
+      $this->derivatives[$block_content->uuid()]['admin_label'] = $block_content->label() ?? ($block_content->type->entity->label() . ': ' . $block_content->id());
+      $this->derivatives[$block_content->uuid()]['config_dependencies']['content'] = [
+        $block_content->getConfigDependencyName(),
+      ];
+    }
+    return parent::getDerivativeDefinitions($base_plugin_definition);
+  }
+
+}

src/Plugin/Menu/LocalAction/BlockContentAddLocalAction.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace Drupal\block_content\Plugin\Menu\LocalAction;
+
+use Drupal\Core\Menu\LocalActionDefault;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Routing\RouteProviderInterface;
+use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * Modifies the 'Add content block' local action.
+ */
+class BlockContentAddLocalAction extends LocalActionDefault {
+
+  /**
+   * Constructs a BlockContentAddLocalAction object.
+   */
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    $plugin_definition,
+    RouteProviderInterface $routeProvider,
+    protected RequestStack $requestStack,
+  ) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition, $routeProvider);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('router.route_provider'),
+      $container->get('request_stack'),
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getOptions(RouteMatchInterface $route_match) {
+    $options = parent::getOptions($route_match);
+    // If the route specifies a theme, append it to the query string.
+    if ($theme = $route_match->getParameter('theme')) {
+      $options['query']['theme'] = $theme;
+    }
+
+    // If the current request has a region, append it to the query string.
+    if ($region = $this->requestStack->getCurrentRequest()->query->getString('region')) {
+      $options['query']['region'] = $region;
+    }
+
+    // Adds a destination on content block listing.
+    if ($route_match->getRouteName() == 'entity.block_content.collection') {
+      $options['query']['destination'] = Url::fromRoute('<current>')->toString();
+    }
+    return $options;
+  }
+
+}

src/Plugin/Validation/Constraint/BlockContentEntityChangedConstraint.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Drupal\block_content\Plugin\Validation\Constraint;
+
+use Drupal\Core\Entity\Plugin\Validation\Constraint\EntityChangedConstraint;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Validation\Attribute\Constraint;
+
+/**
+ * Validation constraint for the block content entity changed timestamp.
+ */
+#[Constraint(
+  id: 'BlockContentEntityChanged',
+  label: new TranslatableMarkup('Block content entity changed', [], ['context' => 'Validation']),
+  type: ['entity']
+)]
+class BlockContentEntityChangedConstraint extends EntityChangedConstraint {
+}

src/Plugin/Validation/Constraint/BlockContentEntityChangedConstraintValidator.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Drupal\block_content\Plugin\Validation\Constraint;
+
+use Drupal\block_content\BlockContentInterface;
+use Drupal\Core\Entity\Plugin\Validation\Constraint\EntityChangedConstraintValidator;
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Validates the BlockContentEntityChanged constraint.
+ */
+class BlockContentEntityChangedConstraintValidator extends EntityChangedConstraintValidator {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate($entity, Constraint $constraint) {
+    // This prevents saving an update to the block via a host entity's form if
+    // the host entity has had other changes made via the API instead of the
+    // entity form, such as a revision revert. This is safe, for example, in the
+    // Layout Builder the inline blocks are not saved until the whole layout is
+    // saved, in which case Layout Builder forces a new revision for the block.
+    // @see \Drupal\layout_builder\InlineBlockEntityOperations::handlePreSave.
+    if ($entity instanceof BlockContentInterface && !$entity->isReusable()) {
+      return;
+    }
+    parent::validate($entity, $constraint);
+  }
+
+}

src/Plugin/migrate/source/d6/Box.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\block_content\Plugin\migrate\source\d6;
+
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Drupal 6 block source from database.
+ *
+ * For available configuration keys, refer to the parent classes.
+ *
+ * @see \Drupal\migrate\Plugin\migrate\source\SqlBase
+ * @see \Drupal\migrate\Plugin\migrate\source\SourcePluginBase
+ *
+ * @MigrateSource(
+ *   id = "d6_box",
+ *   source_module = "block"
+ * )
+ */
+class Box extends DrupalSqlBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    $query = $this->select('boxes', 'b')
+      ->fields('b', ['bid', 'body', 'info', 'format']);
+    $query->orderBy('b.bid');
+
+    return $query;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fields() {
+    return [
+      'bid' => $this->t('The numeric identifier of the block/box'),
+      'body' => $this->t('The block/box content'),
+      'info' => $this->t('Admin title of the block/box.'),
+      'format' => $this->t('Input format of the content block/box content.'),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIds() {
+    $ids['bid']['type'] = 'integer';
+    return $ids;
+  }
+
+}

src/Plugin/migrate/source/d6/BoxTranslation.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Drupal\block_content\Plugin\migrate\source\d6;
+
+use Drupal\block_content\Plugin\migrate\source\d7\BlockCustomTranslation as D7BlockCustomTranslation;
+
+/**
+ * Drupal 6 i18n content block translations source from database.
+ *
+ * For available configuration keys, refer to the parent classes.
+ *
+ * @see \Drupal\migrate\Plugin\migrate\source\SqlBase
+ * @see \Drupal\migrate\Plugin\migrate\source\SourcePluginBase
+ *
+ * @MigrateSource(
+ *   id = "d6_box_translation",
+ *   source_module = "i18nblocks"
+ * )
+ */
+class BoxTranslation extends D7BlockCustomTranslation {
+
+  /**
+   * Drupal 6 table names.
+   */
+  const CUSTOM_BLOCK_TABLE = 'boxes';
+  const I18N_STRING_TABLE = 'i18n_strings';
+
+}

src/Plugin/migrate/source/d7/BlockCustom.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Drupal\block_content\Plugin\migrate\source\d7;
+
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Drupal 7 content block source from database.
+ *
+ * For available configuration keys, refer to the parent classes.
+ *
+ * @see \Drupal\migrate\Plugin\migrate\source\SqlBase
+ * @see \Drupal\migrate\Plugin\migrate\source\SourcePluginBase
+ *
+ * @MigrateSource(
+ *   id = "d7_block_custom",
+ *   source_module = "block"
+ * )
+ */
+class BlockCustom extends DrupalSqlBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    return $this->select('block_custom', 'b')->fields('b');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fields() {
+    return [
+      'bid' => $this->t('The numeric identifier of the block/box'),
+      'body' => $this->t('The block/box content'),
+      'info' => $this->t('Admin title of the block/box.'),
+      'format' => $this->t('Input format of the content block/box content.'),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIds() {
+    $ids['bid']['type'] = 'integer';
+    return $ids;
+  }
+
+}

src/Plugin/migrate/source/d7/BlockCustomTranslation.php

@@ -0,0 +1,105 @@
+<?php
+
+namespace Drupal\block_content\Plugin\migrate\source\d7;
+
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+use Drupal\content_translation\Plugin\migrate\source\I18nQueryTrait;
+
+/**
+ * Drupal 7 i18n content block translations source from database.
+ *
+ * For available configuration keys, refer to the parent classes.
+ *
+ * @see \Drupal\migrate\Plugin\migrate\source\SqlBase
+ * @see \Drupal\migrate\Plugin\migrate\source\SourcePluginBase
+ *
+ * @MigrateSource(
+ *   id = "d7_block_custom_translation",
+ *   source_module = "i18n_block"
+ * )
+ */
+class BlockCustomTranslation extends DrupalSqlBase {
+
+  use I18nQueryTrait;
+
+  /**
+   * Drupal 7 table names.
+   */
+  const CUSTOM_BLOCK_TABLE = 'block_custom';
+  const I18N_STRING_TABLE = 'i18n_string';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function query() {
+    // Build a query based on blockCustomTable table where each row has the
+    // translation for only one property, either title or description. The
+    // method prepareRow() is then used to obtain the translation for the
+    // other property.
+    $query = $this->select(static::CUSTOM_BLOCK_TABLE, 'b')
+      ->fields('b', ['bid', 'format', 'body'])
+      ->fields('i18n', ['property'])
+      ->fields('lt', ['lid', 'translation', 'language'])
+      ->orderBy('b.bid');
+
+    // Use 'title' for the info field to match the property name in
+    // i18nStringTable.
+    $query->addField('b', 'info', 'title');
+
+    // Add in the property, which is either title or body. Cast the bid to text
+    // so PostgreSQL can make the join.
+    $query->leftJoin(static::I18N_STRING_TABLE, 'i18n', '[i18n].[objectid] = CAST([b].[bid] AS CHAR(255))');
+    $query->condition('i18n.type', 'block');
+
+    // Add in the translation for the property.
+    $query->innerJoin('locales_target', 'lt', '[lt].[lid] = [i18n].[lid]');
+    return $query;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function prepareRow(Row $row) {
+    if (!parent::prepareRow($row)) {
+      return FALSE;
+    }
+    // Set the i18n string table for use in I18nQueryTrait.
+    $this->i18nStringTable = static::I18N_STRING_TABLE;
+    // Save the translation for this property.
+    $property_in_row = $row->getSourceProperty('property');
+    // Get the translation for the property not already in the row and save it
+    // in the row.
+    $property_not_in_row = ($property_in_row === 'title') ? 'body' : 'title';
+    return $this->getPropertyNotInRowTranslation($row, $property_not_in_row, 'bid', $this->idMap);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function fields() {
+    return [
+      'bid' => $this->t('The block numeric identifier.'),
+      'format' => $this->t('Input format of the content block/box content.'),
+      'lid' => $this->t('i18n_string table id'),
+      'language' => $this->t('Language for this field.'),
+      'property' => $this->t('Block property'),
+      'translation' => $this->t('The translation of the value of "property".'),
+      'title' => $this->t('Block title.'),
+      'title_translated' => $this->t('Block title translation.'),
+      'body' => $this->t('Block body.'),
+      'body_translated' => $this->t('Block body translation.'),
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getIds() {
+    $ids['bid']['type'] = 'integer';
+    $ids['bid']['alias'] = 'b';
+    $ids['language']['type'] = 'string';
+    return $ids;
+  }
+
+}

src/Plugin/views/area/ListingEmpty.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Drupal\block_content\Plugin\views\area;
+
+use Drupal\Core\Access\AccessManagerInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\Url;
+use Drupal\views\Attribute\ViewsArea;
+use Drupal\views\Plugin\views\area\AreaPluginBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Defines an area plugin to display a block add link.
+ *
+ * @ingroup views_area_handlers
+ */
+#[ViewsArea("block_content_listing_empty")]
+class ListingEmpty extends AreaPluginBase {
+
+  /**
+   * The access manager.
+   *
+   * @var \Drupal\Core\Access\AccessManagerInterface
+   */
+  protected $accessManager;
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $currentUser;
+
+  /**
+   * Constructs a new ListingEmpty.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin ID for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Access\AccessManagerInterface $access_manager
+   *   The access manager.
+   * @param \Drupal\Core\Session\AccountInterface $current_user
+   *   The current user.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, AccessManagerInterface $access_manager, AccountInterface $current_user) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->accessManager = $access_manager;
+    $this->currentUser = $current_user;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('access_manager'),
+      $container->get('current_user')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function render($empty = FALSE) {
+    if (!$empty || !empty($this->options['empty'])) {
+      /** @var \Drupal\Core\Access\AccessResultInterface|\Drupal\Core\Cache\CacheableDependencyInterface $access_result */
+      $access_result = $this->accessManager->checkNamedRoute('block_content.add_page', [], $this->currentUser, TRUE);
+      $element = [
+        '#markup' => $this->t('Add a <a href=":url">content block</a>.', [':url' => Url::fromRoute('block_content.add_page')->toString()]),
+        '#access' => $access_result->isAllowed(),
+        '#cache' => [
+          'contexts' => $access_result->getCacheContexts(),
+          'tags' => $access_result->getCacheTags(),
+          'max-age' => $access_result->getCacheMaxAge(),
+        ],
+      ];
+      return $element;
+    }
+    return [];
+  }
+
+}

src/Plugin/views/wizard/BlockContent.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Drupal\block_content\Plugin\views\wizard;
+
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\views\Attribute\ViewsWizard;
+use Drupal\views\Plugin\views\wizard\WizardPluginBase;
+
+/**
+ * Used for creating 'block_content' views with the wizard.
+ */
+#[ViewsWizard(
+  id: 'block_content',
+  title: new TranslatableMarkup('Content Block'),
+  base_table: 'block_content_field_data'
+)]
+class BlockContent extends WizardPluginBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFilters() {
+    $filters = parent::getFilters();
+    $filters['reusable'] = [
+      'id' => 'reusable',
+      'plugin_id' => 'boolean',
+      'table' => $this->base_table,
+      'field' => 'reusable',
+      'value' => '1',
+      'entity_type' => $this->entityTypeId,
+      'entity_field' => 'reusable',
+    ];
+    return $filters;
+  }
+
+}

src/Routing/RouteSubscriber.php

@@ -0,0 +1,237 @@
+<?php
+
+namespace Drupal\block_content\Routing;
+
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Routing\RouteBuildEvent;
+use Drupal\Core\Routing\RouteSubscriberBase;
+use Drupal\Core\Routing\RoutingEvents;
+use Symfony\Component\Routing\RouteCollection;
+
+/**
+ * Subscriber for Block content BC routes.
+ */
+class RouteSubscriber extends RouteSubscriberBase {
+
+  /**
+   * The entity type manager service.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * The route collection for adding routes.
+   *
+   * @var \Symfony\Component\Routing\RouteCollection
+   */
+  protected $collection;
+
+  /**
+   * The current base path.
+   *
+   * @var string
+   */
+  protected $basePath;
+
+  /**
+   * The BC base path.
+   *
+   * @var string
+   */
+  protected $basePathBc;
+
+  /**
+   * The redirect controller.
+   *
+   * @var string
+   */
+  protected $controller;
+
+  /**
+   * Constructs a RouteSubscriber object.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager service.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler.
+   */
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, ModuleHandlerInterface $module_handler) {
+    $this->entityTypeManager = $entity_type_manager;
+    $this->moduleHandler = $module_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function alterRoutes(RouteCollection $collection) {
+    $this->collection = $collection;
+
+    // @see block_content.routing.yml
+    if ($this->setUpBaseRoute('entity.block_content_type.collection')) {
+      $this->addRedirectRoute('block_content.type_add');
+    }
+
+    $entity_type = $this->entityTypeManager->getDefinition('block_content');
+    if ($this->setUpBaseRoute($entity_type->get('field_ui_base_route'))) {
+      foreach ($this->childRoutes($entity_type) as $route_name) {
+        $this->addRedirectRoute($route_name);
+      }
+    }
+  }
+
+  /**
+   * Gets parameters from a base route and saves them in class variables.
+   *
+   * @param string $base_route_name
+   *   The name of a base route that already has a BC variant.
+   *
+   * @return bool
+   *   TRUE if all parameters are set, FALSE if not.
+   */
+  protected function setUpBaseRoute(string $base_route_name): bool {
+    $base_route = $this->collection->get($base_route_name);
+    $base_route_bc = $this->collection->get("$base_route_name.bc");
+    if (empty($base_route) || empty($base_route_bc)) {
+      return FALSE;
+    }
+
+    $this->basePath = $base_route->getPath();
+    $this->basePathBc = $base_route_bc->getPath();
+    $this->controller = $base_route_bc->getDefault('_controller');
+    if (empty($this->basePath) || empty($this->basePathBc) || empty($this->controller) || $this->basePathBc === $this->basePath) {
+      return FALSE;
+    }
+
+    return TRUE;
+  }
+
+  /**
+   * Adds a redirect route.
+   *
+   * @param string $route_name
+   *   The name of a route whose path has changed.
+   */
+  protected function addRedirectRoute(string $route_name): void {
+    // Exit early if the BC route is already there.
+    if (!empty($this->collection->get("$route_name.bc"))) {
+      return;
+    }
+
+    $route = $this->collection->get($route_name);
+    if (empty($route)) {
+      return;
+    }
+
+    $new_path = $route->getPath();
+    if (!str_starts_with($new_path, $this->basePath)) {
+      return;
+    }
+
+    $bc_route = clone $route;
+    // Set the path to what it was in earlier versions of Drupal.
+    $bc_route->setPath($this->basePathBc . substr($new_path, strlen($this->basePath)));
+    if ($bc_route->getPath() === $route->getPath()) {
+      return;
+    }
+
+    // Replace the handler with the stored redirect controller.
+    $defaults = array_diff_key($route->getDefaults(), array_flip([
+      '_entity_form',
+      '_entity_list',
+      '_entity_view',
+      '_form',
+    ]));
+    $defaults['_controller'] = $this->controller;
+    $bc_route->setDefaults($defaults);
+
+    $this->collection->add("$route_name.bc", $bc_route);
+  }
+
+  /**
+   * Creates a list of routes that need BC redirects.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type.
+   *
+   * @return string[]
+   *   A list of route names.
+   */
+  protected function childRoutes(EntityTypeInterface $entity_type): array {
+    $route_names = [];
+
+    if ($field_ui_base_route = $entity_type->get('field_ui_base_route')) {
+      $updated_routes = new RouteCollection();
+      $updated_routes->add($field_ui_base_route, $this->collection->get($field_ui_base_route));
+      $event = new RouteBuildEvent($updated_routes);
+
+      // Apply route subscribers that add routes based on field_ui_base_route,
+      // in the order of their weights.
+      $subscribers = [
+        'field_ui' => 'field_ui.subscriber',
+        'content_translation' => 'content_translation.subscriber',
+      ];
+      foreach ($subscribers as $module_name => $service_name) {
+        if ($this->moduleHandler->moduleExists($module_name)) {
+          \Drupal::service($service_name)->onAlterRoutes($event);
+        }
+      }
+
+      $updated_routes->remove($field_ui_base_route);
+      $route_names = array_merge($route_names, array_keys($updated_routes->all()));
+      $route_names = array_merge($route_names, [
+        // @see \Drupal\config_translation\Routing\RouteSubscriber::alterRoutes()
+        "config_translation.item.add.{$field_ui_base_route}",
+        "config_translation.item.edit.{$field_ui_base_route}",
+        "config_translation.item.delete.{$field_ui_base_route}",
+      ]);
+    }
+
+    if ($entity_type_id = $entity_type->getBundleEntityType()) {
+      $route_names = array_merge($route_names, [
+        // @see \Drupal\Core\Entity\Routing\DefaultHtmlRouteProvider::getRoutes()
+        "entity.{$entity_type_id}.delete_form",
+        // @see \Drupal\config_translation\Routing\RouteSubscriber::alterRoutes()
+        "entity.{$entity_type_id}.config_translation_overview",
+        // @see \Drupal\user\Entity\EntityPermissionsRouteProvider::getRoutes()
+        "entity.{$entity_type_id}.entity_permissions_form",
+      ]);
+    }
+
+    if ($entity_id = $entity_type->id()) {
+      $route_names = array_merge($route_names, [
+        // @see \Drupal\config_translation\Routing\RouteSubscriber::alterRoutes()
+        "entity.field_config.config_translation_overview.{$entity_id}",
+        "config_translation.item.add.entity.field_config.{$entity_id}_field_edit_form",
+        "config_translation.item.edit.entity.field_config.{$entity_id}_field_edit_form",
+        "config_translation.item.delete.entity.field_config.{$entity_id}_field_edit_form",
+        // @see \Drupal\layout_builder\Plugin\SectionStorage\DefaultsSectionStorage::buildRoutes()
+        "layout_builder.defaults.{$entity_id}.disable",
+        "layout_builder.defaults.{$entity_id}.discard_changes",
+        "layout_builder.defaults.{$entity_id}.view",
+      ]);
+    }
+
+    return $route_names;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents(): array {
+    $events = parent::getSubscribedEvents();
+    // Go after ContentTranslationRouteSubscriber.
+    $events[RoutingEvents::ALTER] = ['onAlterRoutes', -300];
+    return $events;
+  }
+
+}

templates/block-content-add-list.html.twig

@@ -0,0 +1,24 @@
+{#
+/**
+ * @file
+ * Default theme implementation to present a list of block types.
+ *
+ * Available variables:
+ * - types: A collection of all the available content block types.
+ *   Each block type contains the following:
+ *   - link: A link to add a block of this type.
+ *   - description: A description of this block type.
+ *
+ * @see template_preprocess_block_content_add_list()
+ *
+ * @ingroup themeable
+ */
+#}
+{% apply spaceless %}
+  <dl>
+    {% for type in types %}
+      <dt>{{ type.link }}</dt>
+      <dd>{{ type.description }}</dd>
+    {% endfor %}
+  </dl>
+{% endapply %}

tests/fixtures/update/views.view.block_content_2862564.yml

@@ -0,0 +1,540 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+    - user
+id: block_content
+label: 'Content blocks'
+module: views
+description: 'Create and edit content blocks.'
+tag: default
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    id: default
+    display_title: Default
+    display_plugin: default
+    position: 0
+    display_options:
+      title: 'Content blocks'
+      fields:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: null
+          entity_field: info
+          plugin_id: field
+          label: 'Block description'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: string
+          settings:
+            link_to_entity: true
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        type:
+          id: type
+          table: block_content_field_data
+          field: type
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: type
+          plugin_id: field
+          label: 'Block type'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: target_id
+          type: entity_reference_label
+          settings:
+            link: false
+          group_column: target_id
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        changed:
+          id: changed
+          table: block_content_field_data
+          field: changed
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: changed
+          plugin_id: field
+          label: Updated
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          type: timestamp
+          settings:
+            date_format: short
+            custom_date_format: ''
+            timezone: ''
+        operations:
+          id: operations
+          table: block_content
+          field: operations
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          plugin_id: entity_operations
+          label: Operations
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          destination: true
+      pager:
+        type: mini
+        options:
+          offset: 0
+          items_per_page: 50
+          total_pages: null
+          id: 0
+          tags:
+            next: 'Next ›'
+            previous: '‹ Previous'
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: true
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      access:
+        type: perm
+        options:
+          perm: 'administer blocks'
+      cache:
+        type: tag
+        options: {  }
+      empty:
+        area_text_custom:
+          id: area_text_custom
+          table: views
+          field: area_text_custom
+          relationship: none
+          group_type: group
+          admin_label: ''
+          plugin_id: text_custom
+          empty: true
+          content: 'There are no content blocks available.'
+          tokenize: false
+        block_content_listing_empty:
+          id: block_content_listing_empty
+          table: block_content
+          field: block_content_listing_empty
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          plugin_id: block_content_listing_empty
+          label: ''
+          empty: true
+      sorts: {  }
+      arguments: {  }
+      filters:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: info
+          plugin_id: string
+          operator: contains
+          value: ''
+          group: 1
+          exposed: true
+          expose:
+            operator_id: info_op
+            label: 'Block description'
+            description: ''
+            use_operator: false
+            operator: info_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: info
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+        type:
+          id: type
+          table: block_content_field_data
+          field: type
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: type
+          plugin_id: bundle
+          operator: in
+          value: {  }
+          group: 1
+          exposed: true
+          expose:
+            operator_id: type_op
+            label: 'Block type'
+            description: ''
+            use_operator: false
+            operator: type_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: type
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+            reduce: false
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+        reusable:
+          id: reusable
+          table: block_content_field_data
+          field: reusable
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: block_content
+          entity_field: reusable
+          plugin_id: boolean
+          operator: '='
+          value: '1'
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+      style:
+        type: table
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          columns:
+            info: info
+            type: type
+            changed: changed
+            operations: operations
+          default: changed
+          info:
+            info:
+              sortable: true
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            type:
+              sortable: true
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            changed:
+              sortable: true
+              default_sort_order: desc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+            operations:
+              sortable: false
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+          override: true
+          sticky: false
+          summary: ''
+          empty_table: true
+          caption: ''
+          description: ''
+      row:
+        type: fields
+      query:
+        type: views_query
+        options:
+          query_comment: ''
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_tags: {  }
+      relationships: {  }
+      header: {  }
+      footer: {  }
+      display_extenders: {  }
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+        - user.permissions
+      tags: {  }
+  page_1:
+    id: page_1
+    display_title: Page
+    display_plugin: page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: admin/content/block
+      menu:
+        type: tab
+        title: 'Blocks'
+        description: 'Create and edit content blocks.'
+        weight: 0
+        menu_name: admin
+        parent: system.admin_content
+        context: '0'
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+        - user.permissions
+      tags: {  }

tests/modules/block_content_test/block_content_test.info.yml

@@ -0,0 +1,7 @@
+name: "Content Block module tests"
+type: module
+description: "Support module for content block related testing."
+package: Testing
+version: VERSION
+dependencies:
+  - drupal:block_content

tests/modules/block_content_test/block_content_test.module

@@ -0,0 +1,69 @@
+<?php
+
+/**
+ * @file
+ * A dummy module for testing content block related hooks.
+ *
+ * This is a dummy module that implements content block related hooks to test API
+ * interaction with the block_content module.
+ */
+
+use Drupal\block_content\Entity\BlockContent;
+
+/**
+ * Implements hook_block_content_view().
+ */
+function block_content_test_block_content_view(array &$build, BlockContent $block_content, $view_mode) {
+  // Add extra content.
+  $build['extra_content'] = [
+    '#markup' => '<blink>Wow</blink>',
+  ];
+}
+
+/**
+ * Implements hook_block_content_presave().
+ */
+function block_content_test_block_content_presave(BlockContent $block_content) {
+  if ($block_content->label() == 'testing_block_content_presave') {
+    $block_content->setInfo($block_content->label() . '_presave');
+  }
+  // Determine changes.
+  if (!empty($block_content->original) && $block_content->original->label() == 'test_changes') {
+    if ($block_content->original->label() != $block_content->label()) {
+      $block_content->setInfo($block_content->label() . '_presave');
+      // Drupal 1.0 release.
+      $block_content->changed = 979534800;
+    }
+  }
+}
+
+/**
+ * Implements hook_block_content_update().
+ */
+function block_content_test_block_content_update(BlockContent $block_content) {
+  // Determine changes on update.
+  if (!empty($block_content->original) && $block_content->original->label() == 'test_changes') {
+    if ($block_content->original->label() != $block_content->label()) {
+      $block_content->setInfo($block_content->label() . '_update');
+    }
+  }
+}
+
+/**
+ * Implements hook_block_content_insert().
+ *
+ * This tests saving a block_content on block_content insert.
+ *
+ * @see \Drupal\block_content\Tests\BlockContentSaveTest::testBlockContentSaveOnInsert()
+ */
+function block_content_test_block_content_insert(BlockContent $block_content) {
+  // Set the block_content title to the block_content ID and save.
+  if ($block_content->label() == 'new') {
+    $block_content->setInfo('BlockContent ' . $block_content->id());
+    $block_content->setNewRevision(FALSE);
+    $block_content->save();
+  }
+  if ($block_content->label() == 'fail_creation') {
+    throw new Exception('Test exception for rollback.');
+  }
+}

tests/modules/block_content_test/block_content_test.routing.yml

@@ -0,0 +1,6 @@
+block_content_test.block_content_view:
+  path: '/block-content/{block_content}'
+  defaults:
+    _entity_view: 'block_content'
+  requirements:
+    _entity_access: 'block_content.view'

tests/modules/block_content_test/config/install/block.block.foobar_gorilla.yml

@@ -0,0 +1,26 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+  theme:
+    - stark
+id: foobar_gorilla
+theme: stark
+region: content
+weight: null
+provider: null
+plugin: 'block_content:fb5e8434-3617-4a1d-a252-8273e95ec30e'
+settings:
+  id: 'block_content:fb5e8434-3617-4a1d-a252-8273e95ec30e'
+  label: 'Foobar Gorilla'
+  label_display: visible
+  provider: block_content
+  status: true
+  info: ''
+  view_mode: default
+visibility:
+  request_path:
+    id: request_path
+    negate: false
+    pages: ''

tests/modules/block_content_test/src/Plugin/EntityReferenceSelection/TestSelection.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace Drupal\block_content_test\Plugin\EntityReferenceSelection;
+
+use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;
+
+/**
+ * Test EntityReferenceSelection with conditions on the 'reusable' field.
+ */
+class TestSelection extends DefaultSelection {
+
+  /**
+   * The condition type.
+   *
+   * @var string
+   */
+  protected $conditionType;
+
+  /**
+   * Whether to set the condition for reusable or non-reusable blocks.
+   *
+   * @var bool
+   */
+  protected $isReusable;
+
+  /**
+   * Sets the test mode.
+   *
+   * @param string $condition_type
+   *   The condition type.
+   * @param bool $is_reusable
+   *   Whether to set the condition for reusable or non-reusable blocks.
+   */
+  public function setTestMode($condition_type = NULL, $is_reusable = NULL) {
+    $this->conditionType = $condition_type;
+    $this->isReusable = $is_reusable;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
+    $query = parent::buildEntityQuery($match, $match_operator);
+    if ($this->conditionType) {
+      /** @var \Drupal\Core\Database\Query\ConditionInterface $add_condition */
+      $add_condition = NULL;
+      switch ($this->conditionType) {
+        case 'base':
+          $add_condition = $query;
+          break;
+
+        case 'group':
+          $group = $query->andConditionGroup()
+            ->exists('type');
+          $add_condition = $group;
+          $query->condition($group);
+          break;
+
+        case "nested_group":
+          $query->exists('type');
+          $sub_group = $query->andConditionGroup()
+            ->exists('type');
+          $add_condition = $sub_group;
+          $group = $query->andConditionGroup()
+            ->exists('type')
+            ->condition($sub_group);
+          $query->condition($group);
+          break;
+      }
+      if ($this->isReusable) {
+        $add_condition->condition('reusable', 1);
+      }
+      else {
+        $add_condition->condition('reusable', 0);
+      }
+    }
+    return $query;
+  }
+
+}

tests/modules/block_content_test_views/block_content_test_views.info.yml

@@ -0,0 +1,8 @@
+name: 'Block Content test views'
+type: module
+description: 'Provides default views for views block_content tests.'
+package: Testing
+version: VERSION
+dependencies:
+  - drupal:block_content
+  - drupal:views

tests/modules/block_content_test_views/test_views/views.view.test_block_content_redirect_destination.yml

@@ -0,0 +1,233 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_block_content_redirect_destination
+label: 'Redirect destination'
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Default
+    position: 0
+    display_options:
+      access:
+        type: none
+        options: {  }
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: mini
+        options:
+          items_per_page: 10
+          offset: 0
+          id: 0
+          total_pages: null
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+          tags:
+            previous: ‹‹
+            next: ››
+      style:
+        type: table
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          override: true
+          sticky: false
+          caption: ''
+          summary: ''
+          description: ''
+          columns:
+            info: info
+          info:
+            info:
+              sortable: false
+              default_sort_order: asc
+              align: ''
+              separator: ''
+              empty_column: false
+              responsive: ''
+          default: '-1'
+          empty_table: false
+      row:
+        type: 'entity:block_content'
+      fields:
+        info:
+          table: block_content_field_data
+          field: info
+          id: info
+          entity_type: null
+          entity_field: info
+          plugin_id: field
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: string
+          settings: {  }
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        operations:
+          id: operations
+          table: block_content
+          field: operations
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: 'Operations links'
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          destination: true
+          entity_type: block_content
+          plugin_id: entity_operations
+      filters: {  }
+      sorts: {  }
+      title: 'Redirect destination'
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      arguments: {  }
+      display_extenders: {  }
+    cache_metadata:
+      max-age: 0
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url.query_args
+      tags: {  }
+  page_1:
+    display_plugin: page
+    id: page_1
+    display_title: Page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: /admin/content/redirect_destination
+    cache_metadata:
+      max-age: 0
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url.query_args
+      tags: {  }

tests/modules/block_content_test_views/test_views/views.view.test_block_content_revision_id.yml

@@ -0,0 +1,66 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_block_content_revision_id
+label: test_block_content_revision_id
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_revision
+base_field: revision_id
+display:
+  default:
+    display_options:
+      relationships:
+        id:
+          id: id
+          table: block_content_field_revision
+          field: id
+          required: true
+          plugin_id: standard
+      fields:
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: revision_id
+        id_1:
+          id: id_1
+          table: block_content_field_revision
+          field: id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: id
+        id:
+          id: id
+          table: block_content_field_data
+          field: id
+          relationship: id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: id
+      arguments:
+        id:
+          id: id
+          table: block_content_field_revision
+          field: id
+          plugin_id: numeric
+          entity_type: block_content
+          entity_field: id
+      sorts:
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          order: ASC
+          plugin_id: field
+          entity_type: block_content
+          entity_field: revision_id
+    display_plugin: default
+    display_title: Default
+    id: default
+    position: 0

tests/modules/block_content_test_views/test_views/views.view.test_block_content_revision_revision_id.yml

@@ -0,0 +1,69 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_block_content_revision_revision_id
+label: test_block_content_revision_revision_id
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_revision
+base_field: revision_id
+display:
+  default:
+    display_options:
+      relationships:
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          required: true
+          entity_type: block_content
+          entity_field: revision_id
+          plugin_id: standard
+      fields:
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: revision_id
+        id_1:
+          id: id_1
+          table: block_content_field_revision
+          field: id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: id
+        id:
+          id: id
+          table: block_content_field_data
+          field: id
+          relationship: revision_id
+          plugin_id: field
+          entity_type: block_content
+          entity_field: id
+      arguments:
+        id:
+          id: id
+          table: block_content_field_revision
+          field: id
+          plugin_id: block_content_id
+          entity_type: block_content
+          entity_field: id
+      sorts:
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          order: ASC
+          plugin_id: field
+          entity_type: block_content
+          entity_field: revision_id
+      display_extenders: {  }
+    display_plugin: default
+    display_title: Default
+    id: default
+    position: 0

tests/modules/block_content_test_views/test_views/views.view.test_block_content_revision_user.yml

@@ -0,0 +1,324 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+    - user
+id: test_block_content_revision_user
+label: 'Test block content revision user'
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Default
+    position: 0
+    display_options:
+      access:
+        type: perm
+        options:
+          perm: 'access content'
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: none
+        options:
+          offset: 0
+      style:
+        type: default
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          uses_fields: false
+      row:
+        type: fields
+        options:
+          inline: {  }
+          separator: ''
+          hide_empty: false
+          default_field_elements: true
+      fields:
+        id:
+          id: id
+          table: block_content_field_revision
+          field: id
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: number_integer
+          settings:
+            thousand_separator: ''
+            prefix_suffix: false
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          entity_type: block_content
+          entity_field: id
+          plugin_id: field
+        revision_id:
+          id: revision_id
+          table: block_content_field_revision
+          field: revision_id
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: number_integer
+          settings:
+            thousand_separator: ''
+            prefix_suffix: false
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          entity_type: block_content
+          entity_field: revision_id
+          plugin_id: field
+        revision_user:
+          id: revision_user
+          table: block_content_revision
+          field: revision_user
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: target_id
+          type: entity_reference_label
+          settings:
+            link: false
+          group_column: target_id
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          entity_type: block_content
+          entity_field: revision_user
+          plugin_id: field
+      filters:
+        revision_user:
+          id: revision_user
+          table: block_content_revision
+          field: revision_user
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: in
+          value: {  }
+          group: 1
+          exposed: true
+          expose:
+            operator_id: revision_user_op
+            label: 'Revision user'
+            description: ''
+            use_operator: false
+            operator: revision_user_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: revision_user
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+            reduce: false
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          entity_type: block_content
+          entity_field: revision_user
+          plugin_id: user_name
+      sorts: {  }
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      arguments: {  }
+      display_extenders: {  }
+      filter_groups:
+        operator: AND
+        groups: {  }
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - 'user.block_content_grants:view'
+        - user.permissions
+      tags: {  }

tests/modules/block_content_test_views/test_views/views.view.test_block_content_view.yml

@@ -0,0 +1,190 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_block_content_view
+label: test_block_content_view
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Default
+    position: null
+    display_options:
+      access:
+        type: none
+        options: {  }
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: full
+        options:
+          items_per_page: 10
+          offset: 0
+          id: 0
+          total_pages: null
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+          tags:
+            previous: '‹ Previous'
+            next: 'Next ›'
+            first: '« First'
+            last: 'Last »'
+          quantity: 9
+      style:
+        type: default
+      row:
+        type: fields
+      fields:
+        id:
+          id: id
+          table: block_content_field_data
+          field: id
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: Id
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          plugin_id: field
+          entity_type: block_content
+          entity_field: id
+      sorts:
+        id:
+          id: id
+          table: block_content_field_data
+          field: id
+          relationship: none
+          group_type: group
+          admin_label: ''
+          order: ASC
+          exposed: false
+          expose:
+            label: ''
+          entity_type: block_content
+          entity_field: id
+          plugin_id: standard
+      title: test_block_content_view
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      display_extenders: {  }
+      arguments:
+        type:
+          id: type
+          table: block_content_field_data
+          field: type
+          relationship: none
+          group_type: group
+          admin_label: ''
+          default_action: 'not found'
+          exception:
+            value: all
+            title_enable: false
+            title: All
+          title_enable: false
+          title: ''
+          default_argument_type: fixed
+          default_argument_options:
+            argument: ''
+          summary_options:
+            base_path: ''
+            count: true
+            items_per_page: 25
+            override: false
+          summary:
+            sort_order: asc
+            number_of_records: 0
+            format: default_summary
+          specify_validation: false
+          validate:
+            type: none
+            fail: 'not found'
+          validate_options: {  }
+          glossary: false
+          limit: 0
+          case: none
+          path_case: none
+          transform_dash: false
+          break_phrase: false
+          entity_type: block_content
+          entity_field: type
+          plugin_id: string
+  page_1:
+    display_plugin: page
+    id: page_1
+    display_title: Page
+    position: null
+    display_options:
+      path: test-block_content-view
+      display_extenders: {  }

tests/modules/block_content_test_views/test_views/views.view.test_field_filters.yml

@@ -0,0 +1,338 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_field_filters
+label: 'Test field filters'
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Default
+    position: 0
+    display_options:
+      access:
+        type: none
+        options: {  }
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: none
+        options:
+          items_per_page: 0
+          offset: 0
+      style:
+        type: default
+      row:
+        type: 'entity:block_content'
+        options:
+          relationship: none
+          view_mode: default
+      fields:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          label: ''
+          alter:
+            alter_text: false
+            make_link: false
+            absolute: false
+            trim: false
+            word_boundary: false
+            ellipsis: false
+            strip_tags: false
+            html: false
+          hide_empty: false
+          empty_zero: false
+          relationship: none
+          group_type: group
+          admin_label: ''
+          exclude: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_alter_empty: true
+          entity_type: block_content
+          type: string
+          settings:
+            link_to_entity: true
+          entity_field: title
+          plugin_id: field
+      filters:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: contains
+          value: Paris
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          plugin_id: string
+          entity_type: block_content
+          entity_field: info
+      sorts:
+        changed:
+          id: changed
+          table: block_content_field_data
+          field: changed
+          order: DESC
+          relationship: none
+          group_type: group
+          admin_label: ''
+          exposed: false
+          expose:
+            label: ''
+          granularity: second
+          plugin_id: date
+          entity_type: block_content
+          entity_field: changed
+      title: 'Test field filters'
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      arguments: {  }
+      rendering_language: '***LANGUAGE_entity_translation***'
+      display_extenders: {  }
+  page_bf:
+    display_plugin: page
+    id: page_bf
+    display_title: 'Body filter page'
+    position: 1
+    display_options:
+      path: test-body-filter
+      display_description: ''
+      title: 'Test body filters'
+      defaults:
+        title: false
+        filters: false
+        filter_groups: false
+      filters:
+        body_value:
+          id: body_value
+          table: block_content__body
+          field: body_value
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: contains
+          value: Comida
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          plugin_id: string
+          entity_type: block_content
+          entity_field: body
+      filter_groups:
+        operator: AND
+        groups:
+          1: AND
+      display_extenders: {  }
+  page_bfp:
+    display_plugin: page
+    id: page_bfp
+    display_title: 'Body filter page Paris'
+    position: 1
+    display_options:
+      path: test-body-paris
+      display_description: ''
+      title: 'Test body filters'
+      defaults:
+        title: false
+        filters: false
+        filter_groups: false
+      filters:
+        body_value:
+          id: body_value
+          table: block_content__body
+          field: body_value
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: contains
+          value: Paris
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          plugin_id: string
+          entity_type: block_content
+          entity_field: body
+      filter_groups:
+        operator: AND
+        groups:
+          1: AND
+      display_extenders: {  }
+  page_if:
+    display_plugin: page
+    id: page_if
+    display_title: 'Info filter page'
+    position: 1
+    display_options:
+      path: test-info-filter
+      display_description: ''
+      title: 'Test info filter'
+      defaults:
+        title: false
+        filters: false
+        filter_groups: false
+      filters:
+        info:
+          id: info
+          table: block_content_field_data
+          field: info
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: contains
+          value: Comida
+          group: 1
+          exposed: false
+          expose:
+            operator_id: ''
+            label: ''
+            description: ''
+            use_operator: false
+            operator: ''
+            identifier: ''
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          plugin_id: string
+          entity_type: block_content
+          entity_field: info
+      filter_groups:
+        operator: AND
+        groups:
+          1: AND
+      display_extenders: {  }
+  page_ifp:
+    display_plugin: page
+    id: page_ifp
+    display_title: 'Info filter page Paris'
+    position: 1
+    display_options:
+      path: test-info-paris
+      display_description: ''
+      title: 'Test info filter'
+      defaults:
+        title: false
+      display_extenders: {  }

tests/modules/block_content_test_views/test_views/views.view.test_field_type.yml

@@ -0,0 +1,27 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - block_content
+id: test_field_type
+label: test_field_type
+module: views
+description: ''
+tag: ''
+base_table: block_content_field_data
+base_field: id
+display:
+  default:
+    display_options:
+      fields:
+        type:
+          field: type
+          id: type
+          table: block_content_field_data
+          plugin_id: field
+          entity_type: block_content
+          entity_field: type
+    display_plugin: default
+    display_title: Default
+    id: default
+    position: 0

tests/src/Functional/BlockContentCacheTagsTest.php

@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Tests\system\Functional\Entity\EntityCacheTagsTestBase;
+
+/**
+ * Tests the Content Block entity's cache tags.
+ *
+ * @group block_content
+ */
+class BlockContentCacheTagsTest extends EntityCacheTagsTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block_content'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    $block_content_type = BlockContentType::create([
+      'id' => 'basic',
+      'label' => 'basic',
+      'revision' => FALSE,
+    ]);
+    $block_content_type->save();
+    block_content_add_body_field($block_content_type->id());
+
+    // Create a "Llama" content block.
+    $block_content = BlockContent::create([
+      'info' => 'Llama',
+      'type' => 'basic',
+      'body' => [
+        'value' => 'The name "llama" was adopted by European settlers from native Peruvians.',
+        'format' => 'plain_text',
+      ],
+    ]);
+    $block_content->save();
+
+    return $block_content;
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * @see \Drupal\block_content\BlockContentAccessControlHandler::checkAccess()
+   */
+  protected function getAccessCacheContextsForEntity(EntityInterface $entity) {
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * Each comment must have a comment body, which always has a text format.
+   */
+  protected function getAdditionalCacheTagsForEntity(EntityInterface $entity) {
+    return ['config:filter.format.plain_text'];
+  }
+
+  /**
+   * Tests that the block is cached with the correct contexts and tags.
+   */
+  public function testBlock(): void {
+    $block = $this->drupalPlaceBlock('block_content:' . $this->entity->uuid());
+    $build = $this->container->get('entity_type.manager')->getViewBuilder('block')->view($block, 'block');
+
+    // Render the block.
+    $this->container->get('renderer')->renderRoot($build);
+
+    // Expected keys, contexts, and tags for the block.
+    // @see \Drupal\block\BlockViewBuilder::viewMultiple()
+    $expected_block_cache_keys = ['entity_view', 'block', $block->id()];
+    $expected_block_cache_tags = Cache::mergeTags(['block_view', 'rendered'], $block->getCacheTags());
+    $expected_block_cache_tags = Cache::mergeTags($expected_block_cache_tags, $block->getPlugin()->getCacheTags());
+
+    // Expected contexts and tags for the BlockContent entity.
+    // @see \Drupal\Core\Entity\EntityViewBuilder::getBuildDefaults().
+    $expected_entity_cache_tags = Cache::mergeTags(['block_content_view'], $this->entity->getCacheTags());
+    $expected_entity_cache_tags = Cache::mergeTags($expected_entity_cache_tags, $this->getAdditionalCacheTagsForEntity($this->entity));
+
+    // Verify that what was render cached matches the above expectations.
+    $this->verifyRenderCache($expected_block_cache_keys, Cache::mergeTags($expected_block_cache_tags, $expected_entity_cache_tags), CacheableMetadata::createFromRenderArray($build));
+  }
+
+}

tests/src/Functional/BlockContentContextualLinksTest.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Tests views contextual links on block content.
+ *
+ * @group block_content
+ */
+class BlockContentContextualLinksTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'contextual',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Tests contextual links.
+   */
+  public function testBlockContentContextualLinks(): void {
+    $block_content = $this->createBlockContent();
+
+    $block = $this->placeBlock('block_content:' . $block_content->uuid());
+
+    $user = $this->drupalCreateUser([
+      'administer blocks',
+      'access contextual links',
+    ]);
+    $this->drupalLogin($user);
+
+    $this->drupalGet('<front>');
+    $this->assertSession()->elementAttributeContains('css', 'div[data-contextual-id]', 'data-contextual-id', 'block:block=' . $block->id() . ':langcode=en|block_content:block_content=' . $block_content->id() . ':');
+  }
+
+}

tests/src/Functional/BlockContentCreationTest.php

@@ -0,0 +1,336 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\BlockContentInterface;
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\Core\Database\Database;
+
+// cspell:ignore testblock
+
+/**
+ * Create a block and test saving it.
+ *
+ * @group block_content
+ */
+class BlockContentCreationTest extends BlockContentTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * Enable dummy module that implements hook_block_insert() for exceptions and
+   * field_ui to edit display settings.
+   *
+   * @var array
+   */
+  protected static $modules = ['block_content_test', 'dblog', 'field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'administer blocks',
+    'administer block_content display',
+    'access block library',
+    'administer block content',
+  ];
+
+  /**
+   * Sets the test up.
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Creates a "Basic block" block and verifies its consistency in the database.
+   */
+  public function testBlockContentCreation(): void {
+    $this->drupalLogin($this->adminUser);
+
+    // Create a block.
+    $edit = [];
+    $edit['info[0][value]'] = 'Test Block';
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit, 'Save');
+
+    // Check that the Basic block has been created.
+    $this->assertSession()->pageTextContains('basic ' . $edit['info[0][value]'] . ' has been created.');
+
+    // Check that the view mode setting is hidden because only one exists.
+    $this->assertSession()->fieldNotExists('settings[view_mode]');
+
+    // Check that the block exists in the database.
+    $block = $this->getBlockByLabel($edit['info[0][value]']);
+    $this->assertNotEmpty($block, 'Content Block found in database.');
+  }
+
+  /**
+   * Creates a "Basic page" block with multiple view modes.
+   */
+  public function testBlockContentCreationMultipleViewModes(): void {
+    // Add a new view mode and verify if it is selected as expected.
+    $this->drupalLogin($this->drupalCreateUser(['administer display modes']));
+    $this->drupalGet('admin/structure/display-modes/view/add/block_content');
+    $edit = [
+      'id' => 'test_view_mode',
+      'label' => 'Test View Mode',
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->pageTextContains('Saved the ' . $edit['label'] . ' view mode.');
+
+    $this->drupalLogin($this->adminUser);
+
+    // Create a block.
+    $edit = [];
+    $edit['info[0][value]'] = 'Test Block';
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit, 'Save and configure');
+
+    // Save our block permanently
+    $this->submitForm(['region' => 'content'], 'Save block');
+
+    // Set test_view_mode as a custom display to be available on the list.
+    $this->drupalGet('admin/structure/block-content/manage/basic/display');
+    $custom_view_mode = [
+      'display_modes_custom[test_view_mode]' => 1,
+    ];
+    $this->submitForm($custom_view_mode, 'Save');
+
+    // Go to the configure page and change the view mode.
+    $this->drupalGet('admin/structure/block/manage/stark_testblock');
+
+    // Test the available view mode options.
+    // Verify that the default view mode is available.
+    $this->assertSession()->optionExists('edit-settings-view-mode', 'default');
+    // Verify that the test view mode is available.
+    $this->assertSession()->optionExists('edit-settings-view-mode', 'test_view_mode');
+
+    $view_mode['settings[view_mode]'] = 'test_view_mode';
+    $this->submitForm($view_mode, 'Save block');
+
+    // Check that the view mode setting is shown because more than one exists.
+    $this->drupalGet('admin/structure/block/manage/stark_testblock');
+    $this->assertSession()->fieldExists('settings[view_mode]');
+
+    // Change the view mode.
+    $view_mode['region'] = 'content';
+    $view_mode['settings[view_mode]'] = 'test_view_mode';
+    $this->submitForm($view_mode, 'Save block');
+
+    // Go to the configure page and verify the view mode has changed.
+    $this->drupalGet('admin/structure/block/manage/stark_testblock');
+    $this->assertSession()->fieldValueEquals('settings[view_mode]', 'test_view_mode');
+
+    // Check that the block exists in the database.
+    $block = $this->getBlockByLabel($edit['info[0][value]']);
+    $this->assertNotEmpty($block, 'Content Block found in database.');
+  }
+
+  /**
+   * Tests the redirect workflow of creating a block_content and block.
+   */
+  public function testBlockContentFormSubmitHandlers(): void {
+    $this->drupalLogin($this->adminUser);
+
+    // Create a block and place in block layout.
+    $this->drupalGet('/admin/content/block');
+    $this->clickLink('Add content block');
+    // Verify destination URL, when clicking "Save and configure" this
+    // destination will be ignored.
+    $base = base_path();
+    $url = 'block/add?destination=' . $base . 'admin/content/block';
+    $this->assertSession()->addressEquals($url);
+    $edit = [];
+    $edit['info[0][value]'] = 'Test Block';
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->submitForm($edit, 'Save and configure');
+    $this->assertSession()->pageTextContains('basic ' . $edit['info[0][value]'] . ' has been created.');
+    $this->assertSession()->pageTextContains('Configure block');
+
+    // Verify when editing a block "Save and configure" does not appear.
+    $this->drupalGet('/admin/content/block/1');
+    $this->assertSession()->buttonNotExists('Save and configure');
+
+    // Create a block but go back to block library.
+    $edit = [];
+    $edit['info[0][value]'] = 'Test Block';
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit, 'Save');
+    // Check that the Basic block has been created.
+    $this->assertSession()->pageTextContains('basic ' . $edit['info[0][value]'] . ' has been created.');
+    $this->assertSession()->addressEquals('/admin/content/block');
+
+    // Check that the user is redirected to the block library on edit.
+    $block = $this->getBlockByLabel($edit['info[0][value]']);
+    $this->drupalGet($block->toUrl('edit-form'));
+    $this->submitForm([
+      'info[0][value]' => 'Test Block Updated',
+    ], 'Save');
+    $this->assertSession()->addressEquals('admin/content/block');
+
+    // Test with user who doesn't have permission to place a block.
+    $this->drupalLogin($this->drupalCreateUser(['administer block content']));
+    $this->drupalGet('block/add/basic');
+    $this->assertSession()->buttonNotExists('Save and configure');
+
+  }
+
+  /**
+   * Create a default content block.
+   *
+   * Creates a content block from defaults and ensures that the 'basic block'
+   * type is being used.
+   */
+  public function testDefaultBlockContentCreation(): void {
+    $edit = [];
+    $edit['info[0][value]'] = $this->randomMachineName(8);
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    // Don't pass the content block type in the URL so the default is forced.
+    $this->drupalGet('block/add');
+    $this->submitForm($edit, 'Save');
+
+    // Check that the block has been created and that it is a basic block.
+    $this->assertSession()->pageTextContains('basic ' . $edit['info[0][value]'] . ' has been created.');
+
+    // Check that the block exists in the database.
+    $block = $this->getBlockByLabel($edit['info[0][value]']);
+    $this->assertNotEmpty($block, 'Default Content Block found in database.');
+  }
+
+  /**
+   * Verifies that a transaction rolls back the failed creation.
+   */
+  public function testFailedBlockCreation(): void {
+    // Create a block.
+    try {
+      $this->createBlockContent('fail_creation');
+      $this->fail('Expected exception has not been thrown.');
+    }
+    catch (\Exception $e) {
+      // Expected exception; just continue testing.
+    }
+
+    $connection = Database::getConnection();
+
+    // Check that the block does not exist in the database.
+    $id = $connection->select('block_content_field_data', 'b')
+      ->fields('b', ['id'])
+      ->condition('info', 'fail_creation')
+      ->execute()
+      ->fetchField();
+    $this->assertFalse($id);
+  }
+
+  /**
+   * Tests deleting a block.
+   */
+  public function testBlockDelete(): void {
+    // Create a block.
+    $edit = [];
+    $edit['info[0][value]'] = $this->randomMachineName(8);
+    $body = $this->randomMachineName(16);
+    $edit['body[0][value]'] = $body;
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit, 'Save');
+
+    // Place the block.
+    $instance = [
+      'id' => mb_strtolower($edit['info[0][value]']),
+      'settings[label]' => $edit['info[0][value]'],
+      'region' => 'sidebar_first',
+    ];
+    $block = BlockContent::load(1);
+    $url = 'admin/structure/block/add/block_content:' . $block->uuid() . '/' . $this->config('system.theme')->get('default');
+    $this->drupalGet($url);
+    $this->submitForm($instance, 'Save block');
+
+    $block = BlockContent::load(1);
+
+    // Test getInstances method.
+    $this->assertCount(1, $block->getInstances());
+
+    // Navigate to home page.
+    $this->drupalGet('');
+    $this->assertSession()->pageTextContains($body);
+
+    // Delete the block.
+    $this->drupalGet('admin/content/block/1/delete');
+    $this->assertSession()->pageTextContains('This will also remove 1 placed block instance.');
+
+    $this->submitForm([], 'Delete');
+    $this->assertSession()->pageTextContains('The content block ' . $edit['info[0][value]'] . ' has been deleted.');
+
+    // Create another block and force the plugin cache to flush.
+    $edit2 = [];
+    $edit2['info[0][value]'] = $this->randomMachineName(8);
+    $body2 = $this->randomMachineName(16);
+    $edit2['body[0][value]'] = $body2;
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit2, 'Save');
+
+    $this->assertSession()->responseNotContains('Error message');
+
+    // Create another block with no instances, and test we don't get a
+    // confirmation message about deleting instances.
+    $edit3 = [];
+    $edit3['info[0][value]'] = $this->randomMachineName(8);
+    $body = $this->randomMachineName(16);
+    $edit3['body[0][value]'] = $body;
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit3, 'Save');
+
+    // Show the delete confirm form.
+    $this->drupalGet('admin/content/block/3/delete');
+    $this->assertSession()->pageTextNotContains('This will also remove');
+  }
+
+  /**
+   * Tests placed content blocks create a dependency in the block placement.
+   */
+  public function testConfigDependencies(): void {
+    $block = $this->createBlockContent();
+    // Place the block.
+    $block_placement_id = mb_strtolower($block->label());
+    $instance = [
+      'id' => $block_placement_id,
+      'settings[label]' => $block->label(),
+      'region' => 'sidebar_first',
+    ];
+    $block = BlockContent::load(1);
+    $url = 'admin/structure/block/add/block_content:' . $block->uuid() . '/' . $this->config('system.theme')->get('default');
+    $this->drupalGet($url);
+    $this->submitForm($instance, 'Save block');
+
+    $dependencies = \Drupal::service('config.manager')->findConfigEntityDependenciesAsEntities('content', [$block->getConfigDependencyName()]);
+    $block_placement = reset($dependencies);
+    $this->assertEquals($block_placement_id, $block_placement->id(), "The block placement config entity has a dependency on the block content entity.");
+  }
+
+  /**
+   * Load a block based on the label.
+   */
+  private function getBlockByLabel(string $label): ?BlockContentInterface {
+    $blocks = \Drupal::entityTypeManager()
+      ->getStorage('block_content')
+      ->loadByProperties(['info' => $label]);
+    if (empty($blocks)) {
+      return NULL;
+    }
+    return reset($blocks);
+  }
+
+}

tests/src/Functional/BlockContentListTest.php

@@ -0,0 +1,203 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+
+/**
+ * Tests the listing of content blocks.
+ *
+ * Tests the fallback block content list when Views is disabled.
+ *
+ * @group block_content
+ * @see \Drupal\block\BlockContentListBuilder
+ * @see \Drupal\block_content\Tests\BlockContentListViewsTest
+ */
+class BlockContentListTest extends BlockContentTestBase {
+
+  /**
+   * A user with 'access block library' permission.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $baseUser1;
+
+  /**
+   * A user with access to create and edit custom basic blocks.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $baseUser2;
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'administer blocks',
+    'access block library',
+    'create basic block content',
+    'edit any basic block content',
+    'delete any basic block content',
+    'translate configuration',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block', 'block_content', 'config_translation'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->baseUser1 = $this->drupalCreateUser(['access block library']);
+    $this->baseUser2 = $this->drupalCreateUser([
+      'access block library',
+      'create basic block content',
+      'edit any basic block content',
+      'delete any basic block content',
+    ]);
+  }
+
+  /**
+   * Tests the region value when a new block is saved.
+   */
+  public function testBlockRegionPlacement(): void {
+    $this->drupalLogin($this->drupalCreateUser($this->permissions));
+    $this->drupalGet("admin/structure/block/library/stark", ['query' => ['region' => 'content']]);
+
+    $this->clickLink('Add content block');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [
+      'info[0][value]' => 'foo',
+    ];
+    $this->submitForm($edit, 'Save');
+    $this->assertSession()->fieldValueEquals('region', 'content');
+  }
+
+  /**
+   * Tests the content block listing page with different permissions.
+   */
+  public function testListing(): void {
+    // Test with the admin user.
+    $this->drupalLogin($this->drupalCreateUser(['access block library', 'administer block content']));
+    $this->drupalGet('admin/content/block');
+
+    // Test for the page title.
+    $this->assertSession()->titleEquals('Content blocks | Drupal');
+
+    // Test for the table.
+    $this->assertSession()->elementExists('xpath', '//div[@class="layout-content"]//table');
+
+    // Test the table header, two cells should be present.
+    $this->assertSession()->elementsCount('xpath', '//div[@class="layout-content"]//table/thead/tr/th', 2);
+
+    // Test the contents of each th cell.
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[1]', 'Block description');
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[2]', 'Operations');
+
+    $label = 'Antelope';
+    $new_label = 'Albatross';
+    // Add a new entity using the operations link.
+    $this->clickLink('Add content block');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [];
+    $edit['info[0][value]'] = $label;
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->submitForm($edit, 'Save');
+
+    // Confirm that once the user returns to the listing, the text of the label
+    // (versus elsewhere on the page).
+    $this->assertSession()->elementTextContains('xpath', '//td', $label);
+
+    // Check the number of table row cells.
+    $this->assertSession()->elementsCount('xpath', '//div[@class="layout-content"]//table/tbody/tr[1]/td', 2);
+    // Check the contents of the row. The first cell contains the label,
+    // and the second contains the operations list.
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/tbody/tr[1]/td[1]', $label);
+
+    // Edit the entity using the operations link.
+    $blocks = $this->container
+      ->get('entity_type.manager')
+      ->getStorage('block_content')
+      ->loadByProperties(['info' => $label]);
+    $block = reset($blocks);
+    if (!empty($block)) {
+      $this->assertSession()->linkByHrefExists('admin/content/block/' . $block->id());
+      $this->clickLink('Edit');
+      $this->assertSession()->statusCodeEquals(200);
+      $this->assertSession()->titleEquals("Edit content block $label | Drupal");
+      $edit = ['info[0][value]' => $new_label];
+      $this->submitForm($edit, 'Save');
+    }
+    else {
+      $this->fail('Did not find Albatross block in the database.');
+    }
+
+    // Confirm that once the user returns to the listing, the text of the label
+    // (versus elsewhere on the page).
+    $this->assertSession()->elementTextContains('xpath', '//td', $new_label);
+
+    // Delete the added entity using the operations link.
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $block->id() . '/delete');
+    $this->clickLink('Delete');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->titleEquals("Are you sure you want to delete the content block $new_label? | Drupal");
+    $this->submitForm([], 'Delete');
+
+    // Verify that the text of the label and machine name does not appear in
+    // the list (though it may appear elsewhere on the page).
+    $this->assertSession()->elementTextNotContains('xpath', '//td', $new_label);
+
+    // Confirm that the empty text is displayed.
+    $this->assertSession()->pageTextContains('There are no content blocks yet.');
+
+    $block_content = BlockContent::create([
+      'info' => 'Non-reusable block',
+      'type' => 'basic',
+      'reusable' => FALSE,
+    ]);
+    $block_content->save();
+
+    $this->drupalGet('admin/content/block');
+    // Confirm that the empty text is displayed.
+    $this->assertSession()->pageTextContains('There are no content blocks yet.');
+    // Confirm the non-reusable block is not on the page.
+    $this->assertSession()->pageTextNotContains('Non-reusable block');
+
+    $this->drupalLogout();
+
+    // Create test block for other user tests.
+    $test_block = $this->createBlockContent($label);
+
+    $link_text = t('Add content block');
+    // Test as a user with view only permissions.
+    $this->drupalLogin($this->baseUser1);
+    $this->drupalGet('admin/content/block');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->linkNotExists($link_text);
+    $this->assertSession()->linkByHrefNotExists('admin/content/block/' . $test_block->id());
+    $this->assertSession()->linkByHrefNotExists('admin/content/block/' . $test_block->id() . '/delete');
+
+    $this->drupalLogout();
+
+    // Test as a user with permission to create/edit/delete basic blocks.
+    $this->drupalLogin($this->baseUser2);
+    $this->drupalGet('admin/content/block');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->linkExists($link_text);
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $test_block->id());
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $test_block->id() . '/delete');
+  }
+
+}

tests/src/Functional/BlockContentListViewsTest.php

@@ -0,0 +1,205 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+
+/**
+ * Tests the Views-powered listing of content blocks.
+ *
+ * @group block_content
+ * @see \Drupal\block\BlockContentListBuilder
+ * @see \Drupal\block_content\Tests\BlockContentListTest
+ */
+class BlockContentListViewsTest extends BlockContentTestBase {
+
+  /**
+   * A user with 'access block library' permission.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $baseUser1;
+
+  /**
+   * A user with access to create and edit custom basic blocks.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $baseUser2;
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'administer blocks',
+    'access block library',
+    'create basic block content',
+    'edit any basic block content',
+    'delete any basic block content',
+    'translate configuration',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'block',
+    'block_content',
+    'config_translation',
+    'views',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->baseUser1 = $this->drupalCreateUser(['access block library']);
+    $this->baseUser2 = $this->drupalCreateUser([
+      'access block library',
+      'create basic block content',
+      'edit any basic block content',
+      'delete any basic block content',
+    ]);
+  }
+
+  /**
+   * Tests the content block listing page.
+   */
+  public function testListing(): void {
+    // Test with an admin user.
+    $this->drupalLogin($this->adminUser);
+    $this->drupalGet('admin/content/block');
+
+    // Test for the page title.
+    $this->assertSession()->titleEquals('Content blocks | Drupal');
+
+    // Test for the exposed filters.
+    $this->assertSession()->fieldExists('info');
+    $this->assertSession()->fieldExists('type');
+
+    // Test for the table.
+    $this->assertSession()->elementExists('xpath', '//div[@class="layout-content"]//table');
+
+    // Test the table header, four cells should be present.
+    $this->assertSession()->elementsCount('xpath', '//div[@class="layout-content"]//table/thead/tr/th', 4);
+
+    // Test the contents of each th cell.
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[1]', 'Block description');
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[2]', 'Block type');
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[3]', 'Updated Sort ascending');
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/thead/tr/th[4]', 'Operations');
+
+    $label = 'Antelope';
+    $new_label = 'Albatross';
+    // Add a new entity using the operations link.
+    $this->clickLink('Add content block');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [];
+    $edit['info[0][value]'] = $label;
+    $edit['body[0][value]'] = $this->randomMachineName(16);
+    $this->submitForm($edit, 'Save');
+
+    // Confirm that once the user returns to the listing, the text of the label
+    // (versus elsewhere on the page).
+    $this->assertSession()->elementTextContains('xpath', '//td/a', $label);
+
+    // Check the number of table row cells.
+    $this->assertSession()->elementsCount('xpath', '//div[@class="layout-content"]//table/tbody/tr/td', 4);
+    // Check the contents of each row cell. The first cell contains the label,
+    // the second contains the machine name, and the third contains the
+    // operations list.
+    $this->assertSession()->elementTextEquals('xpath', '//div[@class="layout-content"]//table/tbody/tr/td/a', $label);
+
+    // Edit the entity using the operations link.
+    $blocks = $this->container
+      ->get('entity_type.manager')
+      ->getStorage('block_content')
+      ->loadByProperties(['info' => $label]);
+    $block = reset($blocks);
+    if (!empty($block)) {
+      $this->assertSession()->linkByHrefExists('admin/content/block/' . $block->id());
+      $this->clickLink('Edit');
+      $this->assertSession()->statusCodeEquals(200);
+      $this->assertSession()->titleEquals("Edit content block $label | Drupal");
+      $edit = ['info[0][value]' => $new_label];
+      $this->submitForm($edit, 'Save');
+    }
+    else {
+      $this->fail('Did not find Albatross block in the database.');
+    }
+
+    // Confirm that once the user returns to the listing, the text of the label
+    // (versus elsewhere on the page).
+    $this->assertSession()->elementTextContains('xpath', '//td/a', $new_label);
+
+    // Delete the added entity using the operations link.
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $block->id() . '/delete');
+    $this->clickLink('Delete');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->titleEquals("Are you sure you want to delete the content block $new_label? | Drupal");
+    $this->submitForm([], 'Delete');
+
+    // Verify that the text of the label and machine name does not appear in
+    // the list (though it may appear elsewhere on the page).
+    $this->assertSession()->elementTextNotContains('xpath', '//td', $new_label);
+
+    // Confirm that the empty text is displayed.
+    $this->assertSession()->pageTextContains('There are no content blocks available.');
+    $this->assertSession()->linkExists('content block');
+
+    $block_content = BlockContent::create([
+      'info' => 'Non-reusable block',
+      'type' => 'basic',
+      'reusable' => FALSE,
+    ]);
+    $block_content->save();
+
+    $this->drupalGet('admin/content/block');
+    // Confirm that the empty text is displayed.
+    $this->assertSession()->pageTextContains('There are no content blocks available.');
+    // Confirm the non-reusable block is not on the page.
+    $this->assertSession()->pageTextNotContains('Non-reusable block');
+
+    $this->drupalLogout();
+
+    // Create test block for other user tests.
+    $test_block = $this->createBlockContent($label);
+
+    $link_text = t('Add content block');
+    // Test as a user with view only permissions.
+    $this->drupalLogin($this->baseUser1);
+    $this->drupalGet('admin/content/block');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->linkNotExists($link_text);
+    $matches = $this->xpath('//td[1]');
+    $actual = $matches[0]->getText();
+    $this->assertEquals($label, $actual, 'Label found for test block.');
+    $this->assertSession()->linkNotExists('Edit');
+    $this->assertSession()->linkNotExists('Delete');
+    $this->assertSession()->linkByHrefNotExists('admin/content/block/' . $test_block->id() . '/delete');
+
+    $this->drupalLogout();
+
+    // Test as a user with permission to create/edit/delete basic blocks.
+    $this->drupalLogin($this->baseUser2);
+    $this->drupalGet('admin/content/block');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->linkExists($link_text);
+    $matches = $this->xpath('//td/a');
+    $actual = $matches[0]->getText();
+    $this->assertEquals($label, $actual, 'Label found for test block.');
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $test_block->id());
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $test_block->id() . '/delete');
+  }
+
+}

tests/src/Functional/BlockContentPageViewTest.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Create a block and test block access by attempting to view the block.
+ *
+ * @group block_content
+ */
+class BlockContentPageViewTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block_content_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Checks block edit and fallback functionality.
+   */
+  public function testPageEdit(): void {
+    $this->drupalLogin($this->adminUser);
+    $block = $this->createBlockContent();
+
+    // Attempt to view the block.
+    $this->drupalGet('block-content/' . $block->id());
+
+    // Ensure user was able to view the block.
+    $this->assertSession()->statusCodeEquals(200);
+    $this->drupalGet('<front>');
+    $this->assertSession()->pageTextContains('This block is broken or missing. You may be missing content or you might need to install the original module.');
+  }
+
+}

tests/src/Functional/BlockContentRedirectTest.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Ensures that custom block type functions work correctly.
+ *
+ * @group block_content
+ * @group legacy
+ */
+class BlockContentRedirectTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Tests the deprecation message from the old block-type page.
+   *
+   * @group legacy
+   */
+  public function testBlockContentTypeRedirect(): void {
+    $this->drupalLogin($this->adminUser);
+    $this->expectDeprecation('The path /admin/structure/block/block-content/types is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/structure/block-content. See https://www.drupal.org/node/3320855');
+    $this->drupalGet('/admin/structure/block/block-content/types');
+    $this->assertSession()
+      ->pageTextContains("You have been redirected from admin/structure/block/block-content/types. Update links, shortcuts, and bookmarks to use admin/structure/block-content.");
+  }
+
+  /**
+   * Tests the deprecation message from the old block library page.
+   *
+   * @group legacy
+   */
+  public function testBlockLibraryRedirect(): void {
+    $this->drupalLogin($this->adminUser);
+    $this->expectDeprecation('The path /admin/structure/block/block-content is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block. See https://www.drupal.org/node/3320855');
+    $this->drupalGet('admin/structure/block/block-content');
+    $this->assertSession()
+      ->pageTextContains("You have been redirected from admin/structure/block/block-content. Update links, shortcuts, and bookmarks to use admin/content/block.");
+  }
+
+  /**
+   * Tests the deprecation message from the old block edit page.
+   *
+   * @group legacy
+   */
+  public function testBlockContentEditRedirect(): void {
+    $block = $this->createBlockContent();
+    $this->drupalLogin($this->adminUser);
+    $this->expectDeprecation('The path /block/{block_content} is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block/{block_content}. See https://www.drupal.org/node/3320855');
+    $this->drupalGet("/block/{$block->id()}");
+    $this->assertSession()
+      ->pageTextContains("You have been redirected from block/{$block->id()}. Update links, shortcuts, and bookmarks to use admin/content/block/{$block->id()}.");
+  }
+
+  /**
+   * Tests the deprecation message from the old block delete page.
+   *
+   * @group legacy
+   */
+  public function testBlockContentDeleteRedirect(): void {
+    $block = $this->createBlockContent();
+    $this->drupalLogin($this->adminUser);
+    $this->expectDeprecation('The path /block/{block_content} is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block/{block_content}. See https://www.drupal.org/node/3320855');
+    $this->drupalGet("/block/{$block->id()}/delete");
+    $this->assertSession()
+      ->pageTextContains("You have been redirected from block/{$block->id()}/delete. Update links, shortcuts, and bookmarks to use admin/content/block/{$block->id()}/delete.");
+  }
+
+}

tests/src/Functional/BlockContentRevisionDeleteTest.php

@@ -0,0 +1,96 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Block content revision delete form test.
+ *
+ * @group block_content
+ * @coversDefaultClass \Drupal\Core\Entity\Form\RevisionDeleteForm
+ */
+class BlockContentRevisionDeleteTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $permissions = [
+    'view any basic block content history',
+    'delete any basic block content revisions',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalLogin($this->adminUser);
+    $this->drupalPlaceBlock('page_title_block');
+  }
+
+  /**
+   * Tests revision delete.
+   */
+  public function testDeleteForm(): void {
+    $entity = $this->createBlockContent(save: FALSE)
+      ->setRevisionCreationTime((new \DateTimeImmutable('11 January 2009 4pm'))->getTimestamp())
+      ->setRevisionTranslationAffected(TRUE);
+    $entity->setNewRevision();
+    $entity->save();
+    $revisionId = $entity->getRevisionId();
+
+    // Cannot delete latest revision.
+    $this->drupalGet($entity->toUrl('revision-delete-form'));
+    $this->assertSession()->statusCodeEquals(403);
+
+    // Create a new non default revision.
+    $entity
+      ->setRevisionCreationTime((new \DateTimeImmutable('11 January 2009 5pm'))->getTimestamp())
+      ->setRevisionTranslationAffected(TRUE)
+      ->setNewRevision();
+    $entity->isDefaultRevision(FALSE);
+    $entity->save();
+    $nonDefaultRevisionId = $entity->getRevisionId();
+
+    // Reload the default entity.
+    $revision = \Drupal::entityTypeManager()->getStorage('block_content')
+      ->loadRevision($revisionId);
+    // Cannot delete default revision.
+    $this->drupalGet($revision->toUrl('revision-delete-form'));
+    $this->assertSession()->statusCodeEquals(403);
+    $this->assertFalse($revision->access('delete revision', $this->adminUser, FALSE));
+
+    // Reload the non default entity.
+    $revision2 = \Drupal::entityTypeManager()->getStorage('block_content')
+      ->loadRevision($nonDefaultRevisionId);
+    $this->drupalGet($revision2->toUrl('revision-delete-form'));
+    $this->assertSession()->pageTextContains('Are you sure you want to delete the revision from Sun, 01/11/2009 - 17:00?');
+    $this->assertSession()->buttonExists('Delete');
+    $this->assertSession()->linkExists('Cancel');
+    $this->assertTrue($revision2->access('delete revision', $this->adminUser, FALSE));
+
+    $countRevisions = static function (): int {
+      return (int) \Drupal::entityTypeManager()->getStorage('block_content')
+        ->getQuery()
+        ->accessCheck(FALSE)
+        ->allRevisions()
+        ->count()
+        ->execute();
+    };
+
+    $count = $countRevisions();
+    $this->submitForm([], 'Delete');
+    $this->assertEquals($count - 1, $countRevisions());
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->addressEquals(sprintf('admin/content/block/%s/revisions', $entity->id()));
+    $this->assertSession()->pageTextContains(sprintf('Revision from Sun, 01/11/2009 - 17:00 of basic %s has been deleted.', $entity->label()));
+    $this->assertSession()->elementsCount('css', 'table tbody tr', 1);
+  }
+
+}

tests/src/Functional/BlockContentRevisionRevertTest.php

@@ -0,0 +1,98 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Block content revision form test.
+ *
+ * @group block_content
+ * @coversDefaultClass \Drupal\Core\Entity\Form\RevisionRevertForm
+ */
+class BlockContentRevisionRevertTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $permissions = [
+    'view any basic block content history',
+    'revert any basic block content revisions',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalLogin($this->adminUser);
+    $this->drupalPlaceBlock('page_title_block');
+  }
+
+  /**
+   * Tests revision revert.
+   */
+  public function testRevertForm(): void {
+    $entity = $this->createBlockContent(save: FALSE)
+      ->setRevisionCreationTime((new \DateTimeImmutable('11 January 2009 4pm'))->getTimestamp())
+      ->setRevisionTranslationAffected(TRUE);
+    $entity->setNewRevision();
+    $entity->save();
+    $revisionId = $entity->getRevisionId();
+
+    // Cannot revert latest revision.
+    $this->drupalGet($entity->toUrl('revision-revert-form'));
+    $this->assertSession()->statusCodeEquals(403);
+
+    // Create a new non default revision.
+    $entity
+      ->setRevisionCreationTime((new \DateTimeImmutable('11 January 2009 5pm'))->getTimestamp())
+      ->setRevisionTranslationAffected(TRUE)
+      ->setNewRevision();
+    $entity->isDefaultRevision(FALSE);
+    $entity->save();
+    $nonDefaultRevisionId = $entity->getRevisionId();
+
+    // Reload the default entity.
+    $revision = \Drupal::entityTypeManager()->getStorage('block_content')
+      ->loadRevision($revisionId);
+    // Cannot revert default revision.
+    $this->drupalGet($revision->toUrl('revision-revert-form'));
+    $this->assertSession()->statusCodeEquals(403);
+    $this->assertFalse($revision->access('revert', $this->adminUser, FALSE));
+
+    // Reload the non default entity.
+    $revision2 = \Drupal::entityTypeManager()->getStorage('block_content')
+      ->loadRevision($nonDefaultRevisionId);
+    $this->drupalGet($revision2->toUrl('revision-revert-form'));
+    $this->assertSession()->pageTextContains('Are you sure you want to revert to the revision from Sun, 01/11/2009 - 17:00?');
+    $this->assertSession()->buttonExists('Revert');
+    $this->assertSession()->linkExists('Cancel');
+    $this->assertTrue($revision2->access('revert', $this->adminUser, FALSE));
+
+    $countRevisions = static function (): int {
+      return (int) \Drupal::entityTypeManager()->getStorage('block_content')
+        ->getQuery()
+        ->accessCheck(FALSE)
+        ->allRevisions()
+        ->count()
+        ->execute();
+    };
+
+    $count = $countRevisions();
+    $this->submitForm([], 'Revert');
+    $this->assertEquals($count + 1, $countRevisions());
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->addressEquals(sprintf('admin/content/block/%s/revisions', $entity->id()));
+    $this->assertSession()->pageTextContains(sprintf('basic %s has been reverted to the revision from Sun, 01/11/2009 - 17:00.', $entity->label()));
+    // Three rows, from the top: the newly reverted revision, the revision from
+    // 5pm, and the revision from 4pm.
+    $this->assertSession()->elementsCount('css', 'table tbody tr', 3);
+  }
+
+}

tests/src/Functional/BlockContentRevisionVersionHistoryTest.php

@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+/**
+ * Block content version history test.
+ *
+ * @group block_content
+ * @coversDefaultClass \Drupal\Core\Entity\Controller\VersionHistoryController
+ */
+class BlockContentRevisionVersionHistoryTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $permissions = [
+    'view any basic block content history',
+    'revert any basic block content revisions',
+    'delete any basic block content revisions',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Tests version history page.
+   */
+  public function testVersionHistory(): void {
+    $entity = $this->createBlockContent(save: FALSE);
+
+    $entity
+      ->setInfo('first revision')
+      ->setRevisionCreationTime((new \DateTimeImmutable('1st June 2020 7am'))->getTimestamp())
+      ->setRevisionLogMessage('first revision log')
+      ->setRevisionUser($this->drupalCreateUser(name: 'first author'))
+      ->setNewRevision();
+    $entity->save();
+
+    $entity
+      ->setInfo('second revision')
+      ->setRevisionCreationTime((new \DateTimeImmutable('2nd June 2020 8am'))->getTimestamp())
+      ->setRevisionLogMessage('second revision log')
+      ->setRevisionUser($this->drupalCreateUser(name: 'second author'))
+      ->setNewRevision();
+    $entity->save();
+
+    $entity
+      ->setInfo('third revision')
+      ->setRevisionCreationTime((new \DateTimeImmutable('3rd June 2020 9am'))->getTimestamp())
+      ->setRevisionLogMessage('third revision log')
+      ->setRevisionUser($this->drupalCreateUser(name: 'third author'))
+      ->setNewRevision();
+    $entity->save();
+
+    $this->drupalGet($entity->toUrl('version-history'));
+    $this->assertSession()->elementsCount('css', 'table tbody tr', 3);
+
+    // Order is newest to oldest revision by creation order.
+    $row1 = $this->assertSession()->elementExists('css', 'table tbody tr:nth-child(1)');
+    // Latest revision does not have revert or delete revision operation.
+    $this->assertSession()->elementNotExists('named', ['link', 'Revert'], $row1);
+    $this->assertSession()->elementNotExists('named', ['link', 'Delete'], $row1);
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(1)', 'Current revision');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(1)', 'third revision log');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(1)', '06/03/2020 - 09:00 by third author');
+
+    $row2 = $this->assertSession()->elementExists('css', 'table tbody tr:nth-child(2)');
+    $this->assertSession()->elementExists('named', ['link', 'Revert'], $row2);
+    $this->assertSession()->elementExists('named', ['link', 'Delete'], $row2);
+    $this->assertSession()->elementTextNotContains('css', 'table tbody tr:nth-child(2)', 'Current revision');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(2)', 'second revision log');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(2)', '06/02/2020 - 08:00 by second author');
+
+    $row3 = $this->assertSession()->elementExists('css', 'table tbody tr:nth-child(3)');
+    $this->assertSession()->elementExists('named', ['link', 'Revert'], $row3);
+    $this->assertSession()->elementExists('named', ['link', 'Delete'], $row3);
+    $this->assertSession()->elementTextNotContains('css', 'table tbody tr:nth-child(2)', 'Current revision');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(3)', 'first revision log');
+    $this->assertSession()->elementTextContains('css', 'table tbody tr:nth-child(3)', '06/01/2020 - 07:00 by first author');
+  }
+
+}

tests/src/Functional/BlockContentRevisionsTest.php

@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\user\UserInterface;
+
+/**
+ * Create a block with revisions.
+ *
+ * @group block_content
+ */
+class BlockContentRevisionsTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Stores blocks created during the test.
+   * @var array
+   */
+  protected $blocks;
+
+  /**
+   * Stores log messages used during the test.
+   * @var array
+   */
+  protected $revisionLogs;
+
+  /**
+   * Sets the test up.
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create initial block.
+    $block = $this->createBlockContent('initial');
+
+    $blocks = [];
+    $logs = [];
+
+    // Get original block.
+    $blocks[] = $block->getRevisionId();
+    $logs[] = '';
+
+    // Create three revisions.
+    $revision_count = 3;
+    for ($i = 0; $i < $revision_count; $i++) {
+      $block->setNewRevision(TRUE);
+      $block->setRevisionLogMessage($this->randomMachineName(32));
+      $block->setRevisionUser($this->adminUser);
+      $block->setRevisionCreationTime(time());
+      $logs[] = $block->getRevisionLogMessage();
+      $block->save();
+      $blocks[] = $block->getRevisionId();
+    }
+
+    $this->blocks = $blocks;
+    $this->revisionLogs = $logs;
+  }
+
+  /**
+   * Checks block revision related operations.
+   */
+  public function testRevisions(): void {
+    $blocks = $this->blocks;
+    $logs = $this->revisionLogs;
+
+    foreach ($blocks as $delta => $revision_id) {
+      // Confirm the correct revision text appears.
+      /** @var \Drupal\block_content\BlockContentInterface  $loaded */
+      $loaded = $this->container->get('entity_type.manager')
+        ->getStorage('block_content')
+        ->loadRevision($revision_id);
+      // Verify revision log is the same.
+      $this->assertEquals($logs[$delta], $loaded->getRevisionLogMessage(), "Correct log message found for revision $revision_id");
+      if ($delta > 0) {
+        $this->assertInstanceOf(UserInterface::class, $loaded->getRevisionUser());
+        $this->assertIsNumeric($loaded->getRevisionUserId());
+        $this->assertIsNumeric($loaded->getRevisionCreationTime());
+      }
+    }
+
+    // Confirm that this is the default revision.
+    $this->assertTrue($loaded->isDefaultRevision(), 'Third block revision is the default one.');
+
+    // Make a new revision and set it to not be default.
+    // This will create a new revision that is not "front facing".
+    // Save this as a non-default revision.
+    $loaded->setNewRevision();
+    $loaded->isDefaultRevision(FALSE);
+    $loaded->body = $this->randomMachineName(8);
+    $loaded->save();
+
+    // Confirm that revision body text is not present on default version of
+    // block.
+    $this->drupalGet('admin/content/block/' . $loaded->id());
+    $this->assertSession()->pageTextNotContains($loaded->body->value);
+
+    // Verify that the non-default revision id is greater than the default
+    // revision id.
+    $default_revision = BlockContent::load($loaded->id());
+    // Verify that the revision ID is greater than the default revision ID.
+    $this->assertGreaterThan($default_revision->getRevisionId(), $loaded->getRevisionId());
+  }
+
+}

tests/src/Functional/BlockContentSaveTest.php

@@ -0,0 +1,112 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+
+/**
+ * Tests $block_content->save() for saving content.
+ *
+ * @group block_content
+ */
+class BlockContentSaveTest extends BlockContentTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block_content_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Sets the test up.
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Checks whether content block IDs are saved properly during an import.
+   */
+  public function testImport(): void {
+    // Content block ID must be a number that is not in the database.
+    $max_id = (int) \Drupal::entityQueryAggregate('block_content')
+      ->accessCheck(FALSE)
+      ->aggregate('id', 'max')
+      ->execute()[0]['id_max'];
+    $test_id = $max_id + mt_rand(1000, 1000000);
+    $info = $this->randomMachineName(8);
+    $block_array = [
+      'info' => $info,
+      'body' => ['value' => $this->randomMachineName(32)],
+      'type' => 'basic',
+      'id' => $test_id,
+    ];
+    $block = BlockContent::create($block_array);
+    $block->enforceIsNew(TRUE);
+    $block->save();
+
+    // Verify that block_submit did not wipe the provided id.
+    $this->assertEquals($test_id, $block->id(), 'Block imported using provide id');
+
+    // Test the import saved.
+    $block_by_id = BlockContent::load($test_id);
+    $this->assertNotEmpty($block_by_id, 'Content block load by block ID.');
+    $this->assertSame($block_array['body']['value'], $block_by_id->body->value);
+  }
+
+  /**
+   * Tests determining changes in hook_block_presave().
+   *
+   * Verifies the static block load cache is cleared upon save.
+   */
+  public function testDeterminingChanges(): void {
+    // Initial creation.
+    $block = $this->createBlockContent('test_changes');
+    // Creating a block should set the changed date to the current time
+    // which is always greater than the time set by hooks we're testing.
+    $this->assertGreaterThan(979534800, $block->getChangedTime(), 'Creating a block sets default "changed" timestamp.');
+
+    // Update the block without applying changes.
+    $block->save();
+    $this->assertEquals('test_changes', $block->label(), 'No changes have been determined.');
+
+    // Apply changes.
+    $block->setInfo('updated');
+    $block->save();
+
+    // The hook implementations block_content_test_block_content_presave() and
+    // block_content_test_block_content_update() determine changes and change
+    // the title as well as programmatically set the 'changed' timestamp.
+    $this->assertEquals('updated_presave_update', $block->label(), 'Changes have been determined.');
+    $this->assertEquals(979534800, $block->getChangedTime(), 'Saving a content block uses "changed" timestamp set in presave hook.');
+
+    // Test the static block load cache to be cleared.
+    $block = BlockContent::load($block->id());
+    $this->assertEquals('updated_presave', $block->label(), 'Static cache has been cleared.');
+  }
+
+  /**
+   * Tests saving a block on block insert.
+   *
+   * This test ensures that a block has been fully saved when
+   * hook_block_content_insert() is invoked, so that the block can be saved again
+   * in a hook implementation without errors.
+   *
+   * @see block_test_block_insert()
+   */
+  public function testBlockContentSaveOnInsert(): void {
+    // block_content_test_block_content_insert() triggers a save on insert if the
+    // title equals 'new'.
+    $block = $this->createBlockContent('new');
+    $this->assertEquals('BlockContent ' . $block->id(), $block->label(), 'Content block saved on block insert.');
+  }
+
+}

tests/src/Functional/BlockContentTestBase.php

@@ -0,0 +1,138 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Sets up block content types.
+ */
+abstract class BlockContentTestBase extends BrowserTestBase {
+
+  /**
+   * Profile to use.
+   *
+   * @var string
+   */
+  protected $profile = 'testing';
+
+  /**
+   * Admin user.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'administer blocks',
+    'access block library',
+    'administer block types',
+    'administer block content',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block', 'block_content'];
+
+  /**
+   * Whether or not to auto-create the basic block type during setup.
+   *
+   * @var bool
+   */
+  protected $autoCreateBasicBlockType = TRUE;
+
+  /**
+   * Sets the test up.
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    if ($this->autoCreateBasicBlockType) {
+      $this->createBlockContentType('basic', TRUE);
+    }
+
+    $this->adminUser = $this->drupalCreateUser($this->permissions);
+    $this->drupalPlaceBlock('local_actions_block');
+  }
+
+  /**
+   * Creates a content block.
+   *
+   * @param bool|string $title
+   *   (optional) Title of block. When no value is given uses a random name.
+   *   Defaults to FALSE.
+   * @param string $bundle
+   *   (optional) Bundle name. Defaults to 'basic'.
+   * @param bool $save
+   *   (optional) Whether to save the block. Defaults to TRUE.
+   *
+   * @return \Drupal\block_content\Entity\BlockContent
+   *   Created content block.
+   */
+  protected function createBlockContent($title = FALSE, $bundle = 'basic', $save = TRUE) {
+    $title = $title ?: $this->randomMachineName();
+    $block_content = BlockContent::create([
+      'info' => $title,
+      'type' => $bundle,
+      'langcode' => 'en',
+    ]);
+    if ($block_content && $save === TRUE) {
+      $block_content->save();
+    }
+    return $block_content;
+  }
+
+  /**
+   * Creates a block type (bundle).
+   *
+   * @param array|string $values
+   *   The value to create the block content type. If $values is an array
+   *   it should be like: ['id' => 'foo', 'label' => 'Foo']. If $values
+   *   is a string, it will be considered that it represents the label.
+   * @param bool $create_body
+   *   Whether or not to create the body field
+   *
+   * @return \Drupal\block_content\Entity\BlockContentType
+   *   Created block type.
+   */
+  protected function createBlockContentType($values, $create_body = FALSE) {
+    if (is_array($values)) {
+      if (!isset($values['id'])) {
+        do {
+          $id = $this->randomMachineName(8);
+        } while (BlockContentType::load($id));
+      }
+      else {
+        $id = $values['id'];
+      }
+      $values += [
+        'id' => $id,
+        'label' => $id,
+        'revision' => FALSE,
+      ];
+      $bundle = BlockContentType::create($values);
+    }
+    else {
+      $bundle = BlockContentType::create([
+        'id' => $values,
+        'label' => $values,
+        'revision' => FALSE,
+      ]);
+    }
+    $bundle->save();
+    if ($create_body) {
+      block_content_add_body_field($bundle->id());
+    }
+    return $bundle;
+  }
+
+}

tests/src/Functional/BlockContentTranslationUITest.php

@@ -0,0 +1,158 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Tests\content_translation\Functional\ContentTranslationUITestBase;
+
+/**
+ * Tests the block content translation UI.
+ *
+ * @group block_content
+ */
+class BlockContentTranslationUITest extends ContentTranslationUITestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'language',
+    'content_translation',
+    'block',
+    'field_ui',
+    'block_content',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultCacheContexts = [
+    'languages:language_interface',
+    'session',
+    'theme',
+    'url.path',
+    'url.query_args',
+    'user.permissions',
+    'user.roles:authenticated',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    $this->entityTypeId = 'block_content';
+    $this->bundle = 'basic';
+    $this->testLanguageSelector = FALSE;
+    parent::setUp();
+    $this->doSetup();
+
+    $this->drupalPlaceBlock('page_title_block');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setupBundle() {
+    // Create the basic bundle since it is provided by standard.
+    $bundle = BlockContentType::create([
+      'id' => $this->bundle,
+      'label' => $this->bundle,
+      'revision' => FALSE,
+    ]);
+    $bundle->save();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getTranslatorPermissions() {
+    return array_merge(parent::getTranslatorPermissions(), [
+      'translate any entity',
+      'access administration pages',
+      'administer blocks',
+      'administer block_content fields',
+      'access block library',
+      'create basic block content',
+      'edit any basic block content',
+      'delete any basic block content',
+    ]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNewEntityValues($langcode) {
+    return ['info' => $this->randomMachineName()] + parent::getNewEntityValues($langcode);
+  }
+
+  /**
+   * Returns an edit array containing the values to be posted.
+   */
+  protected function getEditValues($values, $langcode, $new = FALSE) {
+    $edit = parent::getEditValues($values, $langcode, $new);
+    foreach ($edit as $property => $value) {
+      if ($property == 'info') {
+        $edit['info[0][value]'] = $value;
+        unset($edit[$property]);
+      }
+    }
+    return $edit;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function doTestBasicTranslation() {
+    parent::doTestBasicTranslation();
+
+    // Ensure that a block translation can be created using the same description
+    // as in the original language.
+    $default_langcode = $this->langcodes[0];
+    $values = $this->getNewEntityValues($default_langcode);
+    $storage = \Drupal::entityTypeManager()->getStorage($this->entityTypeId);
+    /** @var \Drupal\Core\Entity\ContentEntityInterface $entity */
+    $entity = $storage->create(['type' => 'basic'] + $values);
+    $entity->save();
+    $entity->addTranslation('it', $values);
+
+    try {
+      $entity->save();
+    }
+    catch (\Exception $e) {
+      $this->fail('Blocks can have translations with the same "info" value.');
+    }
+
+    // Check that the translate operation link is shown.
+    $this->drupalGet('admin/content/block');
+    $this->assertSession()->linkByHrefExists('admin/content/block/' . $entity->id() . '/translations');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function doTestTranslationEdit() {
+    $storage = $this->container->get('entity_type.manager')
+      ->getStorage($this->entityTypeId);
+    $storage->resetCache([$this->entityId]);
+    $entity = $storage->load($this->entityId);
+    $languages = $this->container->get('language_manager')->getLanguages();
+
+    foreach ($this->langcodes as $langcode) {
+      // We only want to test the title for non-english translations.
+      if ($langcode != 'en') {
+        $options = ['language' => $languages[$langcode]];
+        $url = $entity->toUrl('edit-form', $options);
+        $this->drupalGet($url);
+        $this->assertSession()->pageTextContains("Edit {$entity->bundle()} {$entity->getTranslation($langcode)->label()} [{$languages[$langcode]->getName()} translation]");
+      }
+    }
+  }
+
+}

tests/src/Functional/BlockContentTypeTest.php

@@ -0,0 +1,266 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Url;
+use Drupal\Tests\system\Functional\Menu\AssertBreadcrumbTrait;
+
+/**
+ * Ensures that block type functions work correctly.
+ *
+ * @group block_content
+ */
+class BlockContentTypeTest extends BlockContentTestBase {
+
+  use AssertBreadcrumbTrait;
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['field_ui'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'administer block content',
+    'administer blocks',
+    'administer block_content fields',
+    'administer block types',
+    'administer block content',
+    'access block library',
+  ];
+
+  /**
+   * Whether or not to create an initial block type.
+   *
+   * @var bool
+   */
+  protected $autoCreateBasicBlockType = FALSE;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalPlaceBlock('page_title_block');
+  }
+
+  /**
+   * Tests the order of the block content types on the add page.
+   */
+  public function testBlockContentAddPageOrder(): void {
+    $this->createBlockContentType(['id' => 'bundle_1', 'label' => 'Bundle 1']);
+    $this->createBlockContentType(['id' => 'bundle_2', 'label' => 'Aaa Bundle 2']);
+    $this->drupalLogin($this->adminUser);
+    $this->drupalGet('block/add');
+    $this->assertSession()->pageTextMatches('/Aaa Bundle 2(.*)Bundle 1/');
+  }
+
+  /**
+   * Tests creating a block type programmatically and via a form.
+   */
+  public function testBlockContentTypeCreation(): void {
+    // Log in a test user.
+    $this->drupalLogin($this->adminUser);
+
+    // Test the page with no block-types.
+    $this->drupalGet('block/add');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->pageTextContains('You have not created any block types yet');
+    $this->clickLink('block type creation page');
+
+    // Create a block type via the user interface.
+    $edit = [
+      'id' => 'foo',
+      'label' => 'title for foo',
+    ];
+    $this->submitForm($edit, 'Save and manage fields');
+
+    // Asserts that form submit redirects to the expected manage fields page.
+    $this->assertSession()->addressEquals('admin/structure/block-content/manage/' . $edit['id'] . '/fields');
+
+    $block_type = BlockContentType::load('foo');
+    $this->assertInstanceOf(BlockContentType::class, $block_type);
+
+    $field_definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions('block_content', 'foo');
+    $this->assertTrue(isset($field_definitions['body']), 'Body field created when using the UI to create block content types.');
+
+    // Check that the block type was created in site default language.
+    $default_langcode = \Drupal::languageManager()->getDefaultLanguage()->getId();
+    $this->assertEquals($block_type->language()->getId(), $default_langcode);
+
+    // Create block types programmatically.
+    $this->createBlockContentType('basic', TRUE);
+    $field_definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions('block_content', 'basic');
+    $this->assertTrue(isset($field_definitions['body']), "Body field for 'basic' block type created when using the testing API to create block content types.");
+
+    $this->createBlockContentType('other');
+    $field_definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions('block_content', 'other');
+    $this->assertFalse(isset($field_definitions['body']), "Body field for 'other' block type not created when using the testing API to create block content types.");
+
+    $block_type = BlockContentType::load('other');
+    $this->assertInstanceOf(BlockContentType::class, $block_type);
+
+    $this->drupalGet('block/add/' . $block_type->id());
+    $this->assertSession()->statusCodeEquals(200);
+  }
+
+  /**
+   * Tests editing a block type using the UI.
+   */
+  public function testBlockContentTypeEditing(): void {
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+    // Now create an initial block-type.
+    $this->createBlockContentType('basic', TRUE);
+
+    $this->drupalLogin($this->adminUser);
+    // We need two block types to prevent /block/add redirecting.
+    $this->createBlockContentType('other');
+
+    $field_definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions('block_content', 'other');
+    $this->assertFalse(isset($field_definitions['body']), 'Body field was not created when using the API to create block content types.');
+
+    // Verify that title and body fields are displayed.
+    $this->drupalGet('block/add/basic');
+    $this->assertSession()->pageTextContains('Block description');
+    $this->assertNotEmpty($this->cssSelect('#edit-body-0-value'), 'Body field was found.');
+
+    // Change the block type name.
+    $edit = [
+      'label' => 'Bar',
+    ];
+    $this->drupalGet('admin/structure/block-content/manage/basic');
+    $this->assertSession()->titleEquals('Edit basic block type | Drupal');
+    $this->submitForm($edit, 'Save');
+    $front_page_path = Url::fromRoute('<front>')->toString();
+    $this->assertBreadcrumb('admin/structure/block-content/manage/basic/fields', [
+      $front_page_path => 'Home',
+      'admin/structure/block-content' => 'Block types',
+      'admin/structure/block-content/manage/basic' => 'Edit Bar',
+    ]);
+    \Drupal::service('entity_field.manager')->clearCachedFieldDefinitions();
+
+    $this->drupalGet('block/add');
+    $this->assertSession()->pageTextContains('Bar');
+    $this->clickLink('Bar');
+    // Verify that the original machine name was used in the URL.
+    $this->assertSession()->addressEquals(Url::fromRoute('block_content.add_form', ['block_content_type' => 'basic']));
+
+    // Remove the body field.
+    $this->drupalGet('admin/structure/block-content/manage/basic/fields/block_content.basic.body/delete');
+    $this->submitForm([], 'Delete');
+    // Resave the settings for this type.
+    $this->drupalGet('admin/structure/block-content/manage/basic');
+    $this->submitForm([], 'Save');
+    // Check that the body field doesn't exist.
+    $this->drupalGet('block/add/basic');
+    $this->assertEmpty($this->cssSelect('#edit-body-0-value'), 'Body field was not found.');
+  }
+
+  /**
+   * Tests deleting a block type that still has content.
+   */
+  public function testBlockContentTypeDeletion(): void {
+    // Now create an initial block-type.
+    $this->createBlockContentType('basic', TRUE);
+
+    // Create a block type programmatically.
+    $type = $this->createBlockContentType('foo');
+
+    $this->drupalLogin($this->adminUser);
+
+    // Add a new block of this type.
+    $block = $this->createBlockContent(FALSE, 'foo');
+    // Attempt to delete the block type, which should not be allowed.
+    $this->drupalGet('admin/structure/block-content/manage/' . $type->id() . '/delete');
+    $this->assertSession()->pageTextContains($type->label() . ' is used by 1 content block on your site. You can not remove this block type until you have removed all of the ' . $type->label() . ' blocks.');
+    $this->assertSession()->pageTextNotContains('This action cannot be undone.');
+
+    // Delete the block.
+    $block->delete();
+    // Attempt to delete the block type, which should now be allowed.
+    $this->drupalGet('admin/structure/block-content/manage/' . $type->id() . '/delete');
+    $this->assertSession()->pageTextContains('Are you sure you want to delete the block type ' . $type->id() . '?');
+    $this->assertSession()->pageTextContains('This action cannot be undone.');
+  }
+
+  /**
+   * Tests that redirects work as expected when multiple block types exist.
+   */
+  public function testsBlockContentAddTypes(): void {
+    // Now create an initial block-type.
+    $this->createBlockContentType('basic', TRUE);
+
+    $this->drupalLogin($this->adminUser);
+    // Create two block types programmatically.
+    $this->createBlockContentType('foo');
+    $this->createBlockContentType('bar');
+
+    // Get the content block storage.
+    $storage = $this->container
+      ->get('entity_type.manager')
+      ->getStorage('block_content');
+
+    // Install all themes.
+    $themes = ['olivero', 'stark', 'claro'];
+    \Drupal::service('theme_installer')->install($themes);
+    $theme_settings = $this->config('system.theme');
+    foreach ($themes as $default_theme) {
+      // Change the default theme.
+      $theme_settings->set('default', $default_theme)->save();
+      $this->drupalPlaceBlock('local_actions_block');
+
+      // For each installed theme, go to its block page and test the redirects.
+      foreach ($themes as $theme) {
+        // Test that adding a block from the 'place blocks' form sends you to the
+        // block configure form.
+        $path = $theme == $default_theme ? 'admin/structure/block' : "admin/structure/block/list/$theme";
+        $this->drupalGet($path);
+        $this->clickLink('Place block');
+        $this->clickLink('Add content block');
+        $this->clickLink('foo');
+        // Create a new block.
+        $edit = ['info[0][value]' => $this->randomMachineName(8)];
+        $this->submitForm($edit, 'Save and configure');
+        $blocks = $storage->loadByProperties(['info' => $edit['info[0][value]']]);
+        if (!empty($blocks)) {
+          $block = reset($blocks);
+          $this->assertSession()->addressEquals(Url::fromRoute('block.admin_add', ['plugin_id' => 'block_content:' . $block->uuid(), 'theme' => $theme]));
+          $this->submitForm(['region' => 'content'], 'Save block');
+          $this->assertSession()->addressEquals(Url::fromRoute('block.admin_display_theme', ['theme' => $theme], ['query' => ['block-placement' => $theme . '-' . Html::getClass($edit['info[0][value]'])]]));
+        }
+        else {
+          $this->fail('Could not load created block.');
+        }
+      }
+    }
+
+    // Test that adding a block from the 'content blocks list' doesn't send you
+    // to the block configure form.
+    $this->drupalGet('admin/content/block');
+    $this->clickLink('Add content block');
+    $this->clickLink('foo');
+    $edit = ['info[0][value]' => $this->randomMachineName(8)];
+    $this->submitForm($edit, 'Save');
+    $blocks = $storage->loadByProperties(['info' => $edit['info[0][value]']]);
+    if (!empty($blocks)) {
+      $this->assertSession()->addressEquals(Url::fromRoute('entity.block_content.collection'));
+    }
+    else {
+      $this->fail('Could not load created block.');
+    }
+  }
+
+}

tests/src/Functional/GenericTest.php

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

tests/src/Functional/PageEditTest.php

@@ -0,0 +1,98 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\Tests\system\Functional\Menu\AssertBreadcrumbTrait;
+
+/**
+ * Create a block and test block edit functionality.
+ *
+ * @group block_content
+ */
+class PageEditTest extends BlockContentTestBase {
+
+  use AssertBreadcrumbTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalPlaceBlock('page_title_block');
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+  }
+
+  /**
+   * Checks block edit functionality.
+   */
+  public function testPageEdit(): void {
+    $this->drupalLogin($this->adminUser);
+
+    $title_key = 'info[0][value]';
+    $body_key = 'body[0][value]';
+    // Create block to edit.
+    $edit = [];
+    $edit['info[0][value]'] = $this->randomMachineName(8);
+    $edit[$body_key] = $this->randomMachineName(16);
+    $this->drupalGet('block/add/basic');
+    $this->submitForm($edit, 'Save');
+
+    // Check that the block exists in the database.
+    $blocks = \Drupal::entityQuery('block_content')
+      ->accessCheck(FALSE)
+      ->condition('info', $edit['info[0][value]'])
+      ->execute();
+    $block = BlockContent::load(reset($blocks));
+    $this->assertNotEmpty($block, 'Content block found in database.');
+
+    // Load the edit page.
+    $this->drupalGet('admin/content/block/' . $block->id());
+    $this->assertSession()->fieldValueEquals($title_key, $edit[$title_key]);
+    $this->assertSession()->fieldValueEquals($body_key, $edit[$body_key]);
+
+    // Edit the content of the block.
+    $edit = [];
+    $edit[$title_key] = $this->randomMachineName(8);
+    $edit[$body_key] = $this->randomMachineName(16);
+    // Stay on the current page, without reloading.
+    $this->submitForm($edit, 'Save');
+
+    // Edit the same block, creating a new revision.
+    $this->drupalGet("admin/content/block/" . $block->id());
+    $edit = [];
+    $edit['info[0][value]'] = $this->randomMachineName(8);
+    $edit[$body_key] = $this->randomMachineName(16);
+    $edit['revision'] = TRUE;
+    $this->submitForm($edit, 'Save');
+
+    // Ensure that the block revision has been created.
+    \Drupal::entityTypeManager()->getStorage('block_content')->resetCache([$block->id()]);
+    $revised_block = BlockContent::load($block->id());
+    $this->assertNotSame($block->getRevisionId(), $revised_block->getRevisionId(), 'A new revision has been created.');
+
+    // Test deleting the block.
+    $this->drupalGet("admin/content/block/" . $revised_block->id());
+    $this->clickLink('Delete');
+    $this->assertSession()->pageTextContains('Are you sure you want to delete the content block ' . $revised_block->label() . '?');
+
+    // Test breadcrumb.
+    $trail = [
+      '' => 'Home',
+      'admin/content/block' => 'Content blocks',
+      'admin/content/block/' . $revised_block->id() => $revised_block->label(),
+    ];
+    $this->assertBreadcrumb(
+      'admin/content/block/' . $revised_block->id() . '/delete', $trail
+    );
+  }
+
+}

tests/src/Functional/Rest/BlockContentJsonAnonTest.php

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

tests/src/Functional/Rest/BlockContentJsonBasicAuthTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional\Rest;
+
+use Drupal\Tests\rest\Functional\BasicAuthResourceTestTrait;
+
+/**
+ * @group rest
+ */
+class BlockContentJsonBasicAuthTest extends BlockContentResourceTestBase {
+
+  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';
+
+}

tests/src/Functional/Rest/BlockContentJsonCookieTest.php

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

tests/src/Functional/Rest/BlockContentResourceTestBase.php

@@ -0,0 +1,239 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\block_content\Functional\Rest;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\Core\Cache\Cache;
+use Drupal\Tests\rest\Functional\EntityResource\EntityResourceTestBase;
+
+/**
+ * ResourceTestBase for BlockContent entity.
+ */
+abstract class BlockContentResourceTestBase extends EntityResourceTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['block_content', 'content_translation'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $entityTypeId = 'block_content';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $patchProtectedFieldNames = [
+    'changed' => NULL,
+  ];
+
+  /**
+   * @var \Drupal\block_content\BlockContentInterface
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUpAuthorization($method) {
+    switch ($method) {
+      case 'GET':
+      case 'PATCH':
+        $this->grantPermissionsToTestedRole(['access block library', 'edit any basic block content']);
+        break;
+
+      case 'POST':
+        $this->grantPermissionsToTestedRole(['access block library', 'create basic block content']);
+        break;
+
+      case 'DELETE':
+        $this->grantPermissionsToTestedRole(['delete any basic block content']);
+        break;
+
+      default:
+        $this->grantPermissionsToTestedRole(['administer block content']);
+        break;
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    if (!BlockContentType::load('basic')) {
+      $block_content_type = BlockContentType::create([
+        'id' => 'basic',
+        'label' => 'basic',
+        'revision' => TRUE,
+      ]);
+      $block_content_type->save();
+      block_content_add_body_field($block_content_type->id());
+    }
+
+    // Create a "Llama" content block.
+    $block_content = BlockContent::create([
+      'info' => 'Llama',
+      'type' => 'basic',
+      'body' => [
+        'value' => 'The name "llama" was adopted by European settlers from native Peruvians.',
+        'format' => 'plain_text',
+      ],
+    ])
+      ->setUnpublished();
+    $block_content->save();
+    return $block_content;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedNormalizedEntity() {
+    return [
+      'id' => [
+        [
+          'value' => 1,
+        ],
+      ],
+      'uuid' => [
+        [
+          'value' => $this->entity->uuid(),
+        ],
+      ],
+      'langcode' => [
+        [
+          'value' => 'en',
+        ],
+      ],
+      'reusable' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
+      'type' => [
+        [
+          'target_id' => 'basic',
+          'target_type' => 'block_content_type',
+          'target_uuid' => BlockContentType::load('basic')->uuid(),
+        ],
+      ],
+      'info' => [
+        [
+          'value' => 'Llama',
+        ],
+      ],
+      'revision_log' => [],
+      'changed' => [
+        [
+          'value' => (new \DateTime())->setTimestamp((int) $this->entity->getChangedTime())
+            ->setTimezone(new \DateTimeZone('UTC'))
+            ->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
+      ],
+      'revision_id' => [
+        [
+          'value' => 1,
+        ],
+      ],
+      'revision_created' => [
+        [
+          'value' => (new \DateTime())->setTimestamp((int) $this->entity->getRevisionCreationTime())
+            ->setTimezone(new \DateTimeZone('UTC'))
+            ->format(\DateTime::RFC3339),
+          'format' => \DateTime::RFC3339,
+        ],
+      ],
+      'revision_user' => [],
+      'revision_translation_affected' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
+      'default_langcode' => [
+        [
+          'value' => TRUE,
+        ],
+      ],
+      'body' => [
+        [
+          'value' => 'The name "llama" was adopted by European settlers from native Peruvians.',
+          'format' => 'plain_text',
+          'summary' => NULL,
+          'processed' => "<p>The name &quot;llama&quot; was adopted by European settlers from native Peruvians.</p>\n",
+        ],
+      ],
+      'status' => [
+        [
+          'value' => FALSE,
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getNormalizedPostEntity() {
+    return [
+      'type' => [
+        [
+          'target_id' => 'basic',
+        ],
+      ],
+      'info' => [
+        [
+          'value' => 'Drama llama',
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedUnauthorizedAccessMessage($method) {
+    if (!$this->resourceConfigStorage->load(static::$resourceConfigId)) {
+      return match ($method) {
+        'GET', 'PATCH' => "The 'edit any basic block content' permission is required.",
+        'POST' => "The following permissions are required: 'create basic block content' AND 'access block library'.",
+        'DELETE' => "The 'delete any basic block content' permission is required.",
+        default => parent::getExpectedUnauthorizedAccessMessage($method),
+      };
+    }
+    return match ($method) {
+      'GET' => "The 'access block library' permission is required.",
+      'PATCH' => "The 'edit any basic block content' permission is required.",
+      'POST' => "The following permissions are required: 'create basic block content' AND 'access block library'.",
+      'DELETE' => "The 'delete any basic block content' permission is required.",
+      default => parent::getExpectedUnauthorizedAccessMessage($method),
+    };
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedUnauthorizedEntityAccessCacheability($is_authenticated) {
+    // @see \Drupal\block_content\BlockContentAccessControlHandler()
+    return parent::getExpectedUnauthorizedEntityAccessCacheability($is_authenticated)
+      ->addCacheTags(['block_content:1']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedCacheTags() {
+    return Cache::mergeTags(parent::getExpectedCacheTags(), ['config:filter.format.plain_text']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getExpectedCacheContexts() {
+    return Cache::mergeContexts(['url.site'], $this->container->getParameter('renderer.config')['required_cache_contexts']);
+  }
+
+}

tests/src/Functional/Rest/BlockContentTypeJsonAnonTest.php

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