fix: #3468180 Undefined array key "view_mode" in block_content_theme_suggestions_block_alter

  if ($block_content instanceof BlockContentInterface) {

    $bundle = $content['#block_content']->bundle();

    $view_mode = strtr($variables['elements']['#configuration']['view_mode'], '.', '_');

    $view_mode = strtr($variables['elements']['content']['#view_mode'], '.', '_');

    $suggestions_new[] = 'block__block_content__view__' . $view_mode;

    $suggestions_new[] = 'block__block_content__type__' . $bundle;

name: 'Block Content Theme Suggestions Test'

type: module

description: 'Support module for testing.'

package: Testing

version: VERSION

<?php

/**

 * @file

 * Support module for testing.

 */

declare(strict_types=1);

use Drupal\block_content\BlockContentInterface;

use Drupal\Core\Entity\Display\EntityViewDisplayInterface;

use Drupal\Core\Entity\EntityInterface;

/**

 * Implements hook_theme().

 */

function block_content_theme_suggestions_test_theme(): array {

  // It is necessary to explicitly register the template via hook_theme()

  // because it is added via a module, not a theme.

  return [

    'block__block_content__view_type__basic__full' => [

      'base hook' => 'block',

    ],

  ];

}

/**

 * Implements hook_preprocess_block().

 */

function block_content_theme_suggestions_test_preprocess_block(&$variables): void {

  $block_content = $variables['elements']['content']['#block_content'] ?? NULL;

  if ($block_content instanceof BlockContentInterface) {

    $variables['label'] = $block_content->label();

  }

}

/**

 * Implements hook_node_view().

 */

function block_content_theme_suggestions_test_node_view(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, string $view_mode): void {

  // Provide content for the extra field in the form of a content block.

  if ($display->getComponent('block_content_extra_field_test')) {

    $entity_type_manager = \Drupal::entityTypeManager();

    // Load a block content entity with a known UUID created by test setup.

    // @see \Drupal\Tests\block_content\Functional\BlockContentThemeSuggestionsTest::setUp()

    $block_content = $entity_type_manager->getStorage('block_content')->loadByProperties([

      'uuid' => 'b22c881a-bcfd-4d0c-a41d-3573327705df',

    ]);

    $block_content = reset($block_content);

    $build['block_content_extra_field_test'] = $entity_type_manager->getViewBuilder('block_content')->view($block_content);

  }

}

/**

 * Implements hook_entity_extra_field_info().

 */

function block_content_theme_suggestions_test_entity_extra_field_info(): array {

  // Add an extra field to the test bundle.

  $extra['node']['bundle_with_extra_field']['display']['block_content_extra_field_test'] = [

    'label' => t('Extra field'),

    'description' => t('Extra field description'),

    'weight' => 0,

  ];

  return $extra;

}

{{ label }}

<h1>I am a block content template for a specific bundle and view mode!</h1>

<?php

declare(strict_types=1);

namespace Drupal\Tests\block_content\Functional;

/**

 * Tests block content theme suggestions.

 *

 * @group block_content

 */

class BlockContentThemeSuggestionsTest extends BlockContentTestBase {

  /**

   * Path prefix for the field UI for the test bundle.

   *

   * @var string

   */

  const FIELD_UI_PREFIX = 'admin/structure/types/manage/bundle_with_extra_field';

  /**

   * The UUID for a block content entity.

   */

  protected string $uuid = 'b22c881a-bcfd-4d0c-a41d-3573327705df';

  /**

   * {@inheritdoc}

   */

  protected static $modules = [

    'field_ui',

    'layout_builder',

    'node',

    'block_content_theme_suggestions_test',

  ];

  /**

   * {@inheritdoc}

   */

  protected $defaultTheme = 'stark';

  /**

   * {@inheritdoc}

   */

  protected function setUp(): void {

    parent::setUp();

    // Create a block with a known UUID.

    $block = $this->createBlockContent('Example block!', 'basic', FALSE);

    $block->set('uuid', $this->uuid);

    $block->save();

  }

  /**

   * Test suggestions for content blocks.

   */

  public function testBlockContentThemeSuggestionsContent(): void {

    $this->drupalLogin($this->adminUser);

    $this->drupalPlaceBlock('block_content:' . $this->uuid);

    $this->drupalGet('');

    $this->assertSession()->statusCodeEquals(200);

    $this->assertSession()->pageTextContains('Example block!');

    $this->assertSession()->pageTextContainsOnce('I am a block content template for a specific bundle and view mode!');

  }

  /**

   * Test suggestions for content blocks within extra fields blocks.

   */

  public function testBlockContentThemeSuggestionsExtraField(): void {

    // Extra field blocks are a block plugin provided by layout builder, so

    // enable layouts for the test bundle and view a node of that bundle.

    // A test module injects an extra field referencing a block content entity.

    // @see block_content_theme_suggestions_test.module

    // @see \Drupal\block_content_theme_suggestions_test\Hook\BlockContentThemeSuggestionsTestHooks

    $this->drupalLogin($this->drupalCreateUser([

      'configure any layout',

      'administer node display',

    ]));

    $this->createContentType(['type' => 'bundle_with_extra_field']);

    $this->drupalGet(static::FIELD_UI_PREFIX . '/display/default');

    $this->submitForm(['layout[enabled]' => TRUE], 'Save');

    $node = $this->createNode([

      'type' => 'bundle_with_extra_field',

      'title' => 'The first node title',

    ]);

    $node->save();

    $this->drupalGet('/node/' . $node->id());

    $this->assertSession()->statusCodeEquals(200);

    $this->assertSession()->pageTextContains('Example block!');

    $this->assertSession()->pageTextContains('I am a block content template for a specific bundle and view mode!');

  }

}