edit_ui-8.x-1.x-dev/modules/edit_ui_contextual/edit_ui_contextual.module

<?php

/**
 * @file
 * Contains hook implementations for edit_ui_contextual module.
 */

declare(strict_types = 1);

use Drupal\Core\Block\BlockPluginInterface;

/**
 * Implements hook_block_view_alter().
 */
function edit_ui_contextual_block_view_alter(array &$build, BlockPluginInterface $block) {
  $build['#contextual_links']['edit_ui_contextual'] = [
    'route_parameters' => ['block' => $build['#id']],
  ];
}

/**
 * Implements hook_page_attachments().
 */
function edit_ui_contextual_page_attachments(array &$page) {
  if (
    \Drupal::service('router.admin_context')->isAdminRoute() ||
    !\Drupal::currentUser()->hasPermission('access contextual links')
  ) {
    return;
  }

  $page['#attached']['library'][] = 'edit_ui_contextual/edit_ui_contextual';
}