Feature Request

from time to time I stumble over phpdoc return types like @return HelloWorld|void which are invalid, because void cannot be combined with another type.

since a recent PHPStan release this is now getting reported - but only in final classes:
https://phpstan.org/r/93a4597d-313d-4d93-b8dd-2b1fdbe5dd16

in native PHP types combining a type with |void already results in a runtime error:
https://3v4l.org/vNCne

Diff

it would be great if rector could replace |void in phpdocs

<?php declare(strict_types = 1);

final class HelloWorld
{
    /**
-     * @return HelloWorld|void
+     * @return HelloWorld|null
     */
    public function add()
    {
		if ('POST' !== $_SERVER['REQUEST_METHOD']) {
            return;
        }
		
		return new HelloWorld();
	}
}

after rector turned |void into |null new PHPStan errors might show up in case the method in question did contain a return; without a explicit return value.

Method HelloWorld::add() should return HelloWorld|null but empty return statement found.

at best rector could then even add explicit return null; at the paths which previous just used return;.

<?php declare(strict_types = 1);

final class HelloWorld
{
    /**
     * @return HelloWorld|null
     */
    public function add()
    {
		if ('POST' !== $_SERVER['REQUEST_METHOD']) {
-            return;
+            return null;
        }
		
		return new HelloWorld();
	}
}

in the end it might even be usefull if this would be 2 separate rules, but I am not sure about that yet.