Interface inheritance

[Jxckaroo]

I cant figure out if I am being silly here or not - but I have the below abstract class, which implements an interface:

interface IAbstractClass {
    public function getAll();
}

abstract class AbstractClass implements IAbstractClass {
    public function getAll() {
        return ["test", "array"];
    }
}

Then I have a class, which extends the abstract class:

interface IChildClass {

}

class ChildClass extends AbstractClass implements IChildClass {

}

For some reason PHP Stan cannot find the getAll() method, when calling from the child class (yet PHP storm recognises it & it runs)

$test = new ChildClass();
$test->getAll(); // returns ["test", "array"] - PHP Stan says "undefined method getAll"

Yet, if I change IChildClass to be:

interface IChildClass extends IAbstractClass {

}

It works as expected.

Surely I shouldnt need to do that though, as ChildClass extends AbstractClass anyway? or am I being silly? xD

Any help/explanation is appreciated!

[ondrejmirtes]

Hi, this looks complicated, can you replicate that on phpstan.org?

[Jxckaroo]

Hi,

See here:

https://phpstan.org/r/91051b9a-f792-43c9-bcb9-6fa9a9243d65

Obviously in IoC ChildClass would be IChildClass via binding.

Also, the code actually works perfectly as expected - I am assuming its something to do with how phpstan looks at binds?

[ondrejmirtes]

I don't get it. The code of the Main class does not give you any guarantees the object in $childClass property will have the getAll() method. Someone can construct IChildClass implementation without the method and pass it to Main, crashing your code.

[Jxckaroo]

Yes, after typing this out I now realise the mistake I have made.

I think I just needed to talk it through to someone - apologies!

[orklah]

Note that PHPStorm accepts happily some degree of polymorphism for the sake of having a comprehensive autocomplete list and displaying less errors. This is something static tools can't allow by nature so it's often that PHPStorm will be happy with some code that static tools will flag as an error