I'm trying out phpstan and psalm for php and I would like to write a class that can take different type of objects and return the right one based on the factory to call.
What I'm trying to achieve is that if I pass an object of type A to the Transformer, the compiler knows that a SuperA will be returned.
While I can go without errors in psalm (though I still get SuperA|SuperB instead of the right object), I got an error on what I'm passing in phpstan.
https://phpstan.org/r/4fce6f46-7aea-4f73-8259-df895910f064
https://psalm.dev/r/352e64ea95
Is there a way to do it?
So you want to get SuperA based on A and SuperB based on B.
I'd connect A+SuperA and B+SuperB together like this: https://phpstan.org/r/28e4e6ec-887b-4735-9b34-c034b4fa04ec
/**
* @template TSuper of Super
*/
interface Common
{
}
/**
* @implements Common<SuperA>
*/
class A implements Common
{
}
/**
* @implements Common<SuperB>
*/
class B implements Common
{
}
interface Super
{
}
class SuperA implements Super
{
public function callA(): void{}
}
class SuperB implements Super
{
public function callB(): void{}
}
The factory then needs to have this signature:
/**
* @template T of Super
* @param Common<T> $obj
* @return T
*/
public function transform($obj)