browser_development-8.x-1.x-dev/modules/browser_development_assist/browser_development_assist.module

<?php

/**
 * @file
 * Contains development_assistant.module.
 */

use Drupal\browser_development_assist\Processing\FileSystemStructure;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Asset\AttachedAssetsInterface;

/**
 * Implements hook_help().
 */
function browser_development_assist_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.browser_development_assist':
      $output = '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Allows browser development to') . '</br>';
      $output .= t('be uninstalled on production and replaces') . '</br>';
      $output .= t('certain functionality so the developers') . '</br>';
      $output .= t('final output renders correctly, mitigates') . '</br>';
      $output .= t('potential attack and performance issues.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_library_info_build().
 */
function browser_development_assist_library_info_build() {

  // Attaching file library array.
  $css = FileSystemStructure::getCssFilePath();
  return [
    'browser-development-assist' => [
      'version' => 'VERSION',
      'css' => [
        'theme' => [
          "$css" => []
        ]
      ],
    ],
  ];
}

/**
 * Attaches
 *
 * Implements hook_page_attachments().
 */
function browser_development_assist_page_attachments(array &$page) {
  $active = \Drupal::theme()->getActiveTheme()->getName();
  $current_theme = \Drupal::config('system.theme')->get('default');
  if ($active === $current_theme) {
    $page['#attached']['library'][] =  'browser_development_assist/browser-development-assist';
  }
}


/**
 * Implements hook_css_alter().
 */
function browser_development_assist_css_alter(&$css, AttachedAssetsInterface $assets) {

  $library = \Drupal::service('library.discovery')
    ->getLibraryByName('browser_development_assist', 'browser-development-assist');
  $path = $library['css'][0]['data'];

  if (isset($css[$path])) {
    $css[$path]['group'] = 300;
  }
}