code: private function validateCustomSnippet($customSnippet)
      {
          $snippetName = str_replace(' ', '', $customSnippet);
          $snippetNameData = explode('_', $snippetName, 3);
          $containsEmpty = in_array("", $snippetNameData, true);
          $types = ['init', 'recv', 'hit', 'miss', 'pass', 'fetch', 'error', 'log', 'deliver', 'hash', 'none'];
          $exception = 'Failed to upload VCL snippets. Please make sure the custom VCL snippets 
              follow this naming convention: [vcl_snippet_type]_[priority]_[short_name_description].vcl';
  
          if (count($snippetNameData) < 3) {
              throw new LocalizedException(__($exception));
          }
  
          $inArray = in_array($snippetNameData[0], $types);
          $isNumeric = is_numeric($snippetNameData[1]);
          $isAlphanumeric = preg_match('/^[\w]+$/', $snippetNameData[2]);
  
          if ($containsEmpty || !$inArray || !$isNumeric || !$isAlphanumeric) {
              throw new LocalizedException(__($exception));
          }
          return $snippetNameData;
      }
docs: Validate custom snippet naming convention
  [vcl_snippet_type]_[priority]_[short_name_description].vcl
  
  @param $customSnippet
  @return array
  @throws LocalizedException