.. _php-datetimenotimmutable:

.. _datetimeimmutable-is-not-immutable:

DateTimeImmutable Is Not Immutable
++++++++++++++++++++++++++++++++++

  ``DateTimeImmutable`` is not really immutable because its internal state can be modified after instantiation.
Inspired by the article from ``Matthias Noback``.

.. code-block:: php
   
   <?php
   
   $dt = new DateTimeImmutable('now');
   echo $dt->getTimestamp() . "\n";
   
   $dt->__construct('tomorrow');
   echo $dt->getTimestamp() . "\n";
   
   ?>

See also `Effective immutability with PHPStan <https://matthiasnoback.nl/2022/07/effective-immutability-with-phpstan/>`_.


Suggestions
___________

* Remove the call to the constructor after instantation of a DateTimeImmutable object




Specs
_____

+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Short name   | Php/DateTimeNotImmutable                                                                                                |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Rulesets     | :ref:`All <ruleset-All>`, :ref:`Analyze <ruleset-Analyze>`, :ref:`Changed Behavior <ruleset-Changed-Behavior>`          |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Exakat since | 2.4.5                                                                                                                   |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| PHP Version  | All                                                                                                                     |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Severity     | Minor                                                                                                                   |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Time To Fix  | Quick (30 mins)                                                                                                         |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Precision    | High                                                                                                                    |
+--------------+-------------------------------------------------------------------------------------------------------------------------+
| Available in | `Entreprise Edition <https://www.exakat.io/entreprise-edition>`_, `Exakat Cloud <https://www.exakat.io/exakat-cloud/>`_ |
+--------------+-------------------------------------------------------------------------------------------------------------------------+