.. _structures-noemptyregex:

.. _no-empty-regex:

No Empty Regex
++++++++++++++

  PHP regex don't accept empty regex, nor regex with alphanumeric delimiter.

Most of those errors happen at execution time, when the regex is build dynamically, but still may end empty. At compile time, such `error <https://www.php.net/error>`_ are made when the code is not tested before commit.

.. code-block:: php
   
   <?php
   
   // No empty regex
   preg_match('', $string, $r); 
   
   // Delimiter must be non-alphanumerical
   preg_replace('1abc1', $string, $r); 
   
   // Delimiter must be non-alphanumerical
   preg_replace('1'.$regex.'1', $string, $r); 
   
   ?>

See also `PCRE <https://www.php.net/pcre>`_ and `Delimiters <https://www.php.net/manual/en/regexp.reference.delimiters.php>`_.

Connex PHP features
-------------------

  + `class <https://php-dictionary.readthedocs.io/en/latest/dictionary/class.ini.html>`_


Suggestions
___________

* Fix the regex by adding regex delimiters




Specs
_____

+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Short name   | Structures/NoEmptyRegex                                                                                                                                                                 |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Rulesets     | :ref:`All <ruleset-All>`, :ref:`Analyze <ruleset-Analyze>`, :ref:`CE <ruleset-CE>`, :ref:`CI-checks <ruleset-CI-checks>`                                                                |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Exakat since | 0.11.1                                                                                                                                                                                  |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| PHP Version  | All                                                                                                                                                                                     |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Severity     | Critical                                                                                                                                                                                |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Time To Fix  | Quick (30 mins)                                                                                                                                                                         |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Precision    | Very high                                                                                                                                                                               |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Examples     | :ref:`case-tikiwiki-structures-noemptyregex`                                                                                                                                            |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Available in | `Entreprise Edition <https://www.exakat.io/entreprise-edition>`_, `Community Edition <https://www.exakat.io/community-edition>`_, `Exakat Cloud <https://www.exakat.io/exakat-cloud/>`_ |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+