* Use ``return null;`` when a function explicitly returns ``null`` values and

use ``return;`` when the function returns ``void`` values;

* Do not add the ``void`` return type to methods in tests;

* Use braces to indicate control structure body regardless of the number of

statements it contains;

Documentation

* Add PHPDoc blocks for all classes, methods, and functions (though you may

be asked to remove PHPDoc that do not add value);

* Add PHPDoc blocks for classes, methods, and functions only when they add

relevant information that does not duplicate the name, native type

declaration or context (e.g. ``instanceof`` checks);

* Only use annotations and types defined in `the PHPDoc reference`_. In

order to improve types for static analysis, the following annotations are

also allowed:

* `Generics`_, with the exception of ``@template-covariant``.

* `Conditional return types`_ using the vendor-prefixed ``@psalm-return``;

* `Class constants`_;

* `Callable types`_;

* Group annotations together so that annotations of the same type immediately

follow each other, and annotations of a different type are separated by a

single blank line;

* Omit the ``@return`` tag if the method does not return anything;

* The ``@package`` and ``@subpackage`` annotations are not used;

* Omit the ``@return`` annotation if the method does not return anything;

* Don't inline PHPDoc blocks, even when they contain just one tag (e.g. don't

put ``/** {@inheritdoc} */`` in a single line);

* Don't use one-line PHPDoc blocks on classes, methods and functions, even

when they contain just one annotation (e.g. don't put ``/** {@inheritdoc} */``

in a single line);

* When adding a new class or when making significant changes to an existing class,

an ``@author`` tag with personal contact information may be added, or expanded.

.. _`snake_case`:https://en.wikipedia.org/wiki/Snake_case

.. _`constructor property promotion`:https://www.php.net/manual/en/language.oop5.decon.php#language.oop5.decon.constructor.promotion

.. _`trailing comma`:https://wiki.php.net/rfc/trailing_comma_in_parameter_list

.. _`the PHPDoc reference`:https://docs.phpdoc.org/3.0/guide/references/phpdoc/index.html

.. _`Conditional return types`:https://psalm.dev/docs/annotating_code/type_syntax/conditional_types/

.. _`Class constants`:https://psalm.dev/docs/annotating_code/type_syntax/value_types/#regular-class-constants

.. _`Callable types`:https://psalm.dev/docs/annotating_code/type_syntax/callable_types/

.. _`Generics`:https://psalm.dev/docs/annotating_code/templated_annotations/