Narrow type with phpstan-assert even if we don't directly call the method for some Symfony class/interfaces.

[VincentLanglet]

I recently got an idea for the following issue #179

For context, Symfony expose code which can resume to this:

abstract class Voter
{
    public function vote(string $attribute, $subject, $token): bool {
			if ($this->supports($attribute, $subject) {
				return $this->voteOnAttribute($attribute, $subject, $token);
			}
    }

	abstract protected function supports(string $attribute, $subject): bool;
	abstract protected function voteOnAttribute(string $attribute, $subject, TokenInterface $token): bool;
}

So I'd like that, if I write

class MyVoter extends Voter
{
    /** 
	 * @phpstan-assert-if-true User $subject 
	 * @phpstan-assert-if-true 'a'|'b' $attribute 
	 */
    protected function supports(string $attribute, $subject): bool
    {
        return $subject instanceof User && in_array($attribute, ['a', 'b']);
    }

    protected function voteOnAttribute(string $attribute, $subject, TokenInterface $token): bool
    {
		// I'd like phpstan to narrow $attribute, $subject like if I made the 
		// if ($this->supports($attribute, $subject) {
		// call by myself
    }
}

Do you think it's possible with some TypeSpecifier @ondrejmirtes ? I'm not familiar with this part of PHPStan.
If this logic is possible this could be later generalize to lot of other Symfony interfaces/classes.

[ondrejmirtes]

1. Why do you want to write a type-specifying extension if you're showing the example with @phpstan-assert-if-true that should also work?
2. Sure, what's possible with @phpstan-assert* is also possible with type-specifying extension, and more, that's been true since the beginning :)

[VincentLanglet]

1. Why do you want to write a type-specifying extension if you're showing the example with @phpstan-assert-if-true that should also work?

Because it doesn't work like this https://phpstan.org/r/fb87f7e8-5e3d-4026-98a6-338fe3162b67

[ondrejmirtes]

That doesn't make sense to me - you have no guarantee someone will call supports before calling voteOnAttribute.

But if you want to enforce that, you can: https://phpstan.org/r/bc1e9de0-3dcb-466d-8b0d-e823a3c9f12f

[VincentLanglet]

That doesn't make sense to me - you have no guarantee someone will call supports before calling voteOnAttribute.

That's why I opened the issue in the Symfony plugin, because this specific class have the following comment:
"It is safe to assume that $attribute and $subject already passed the "supports()" method check."

https://github.com/symfony/symfony/blob/1f7bc1098f0b03181095d35b11fa48523864e6f2/src/Symfony/Component/Security/Core/Authorization/Voter/Voter.php#L81-L85

Symfony provide a lot of classes with a supports method and I wanted to find a way to support this architecture.

But if you want to enforce that, you can: phpstan.org/r/bc1e9de0-3dcb-466d-8b0d-e823a3c9f12f

With this, you have a strict-rule error for contravariant issues https://phpstan.org/r/b72f4692-b3a2-4281-93de-a8f740e5ce75 I wanted to avoid.

[ondrejmirtes]

There's no extension to change the current behaviour now.

With this, you have a strict-rule error for contravariant issues

Generics to the rescue: https://phpstan.org/r/51cce0fb-27ac-4fff-b9d4-214878850e54 (notice also there's no duplication of 'a'|'b' and User anymore)

[github-actions]

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