.. index::
    single: Mockery; Gotchas

Gotchas!
========

Mocking objects in PHP has its limitations and gotchas. Some functionality
can't be mocked or can't be mocked YET! If you locate such a circumstance,
please please (pretty please with sugar on top) create a new issue on GitHub
so it can be documented and resolved where possible. Here is a list to note:

1. Classes containing public ``__wakeup()`` methods can be mocked but the
   mocked ``__wakeup()`` method will perform no actions and cannot have
   expectations set for it. This is necessary since Mockery must serialize and
   unserialize objects to avoid some ``__construct()`` insanity and attempting
   to mock a ``__wakeup()`` method as normal leads to a
   ``BadMethodCallException`` being thrown.

2. Mockery has two scenarios where real classes are replaced: Instance mocks
   and alias mocks. Both will generate PHP fatal errors if the real class is
   loaded, usually via a require or include statement. Only use these two mock
   types where autoloading is in place and where classes are not explicitly
   loaded on a per-file basis using ``require()``, ``require_once()``, etc.

3. Internal PHP classes are not entirely capable of being fully analysed using
   ``Reflection``. For example, ``Reflection`` cannot reveal details of
   expected parameters to the methods of such internal classes. As a result,
   there will be problems where a method parameter is defined to accept a
   value by reference (Mockery cannot detect this condition and will assume a
   pass by value on scalars and arrays). If references as internal class
   method parameters are needed, you should use the
   ``\Mockery\Configuration::setInternalClassMethodParamMap()`` method.
   Note, however that internal class parameter overriding is not available in
   PHP 8 since incompatible signatures have been reclassified as fatal errors.

4. Creating a mock implementing a certain interface with incorrect case in the
   interface name, and then creating a second mock implementing the same
   interface, but this time with the correct case, will have undefined behavior
   due to PHP's ``class_exists`` and related functions being case insensitive.
   Using the ``::class`` keyword in PHP can help you avoid these mistakes.

The gotchas noted above are largely down to PHP's architecture and are assumed
to be unavoidable. But - if you figure out a solution (or a better one than
what may exist), let us know!