Implement SerializesCastableAttributes in StateCaster

[piotrjoniec]

Currently, calling toArray on models will not serialize model states to their underlying values. This doesn't seem like correct behavior, as Laravel tries to serialize all objects to their primitive values whenever possible (for example Carbon/DateTime -> string).

This PR implements SerializesCastableAttributes in StateCaster to support this serialization.

[freekmurze]

The tests seem to be failing, could you take a look?

[piotrjoniec]

@freekmurze Fixed. All versions are passing now for sure.

[freekmurze]

Thank you!

[mikerockett]

@freekmurze This has, unfortunately, broken my application, which uses and relies on a jsonSerialize method on the root state class. This method returns an array that is then casted to JSON for my SPA to consume. The change in this PR forces the underlying value to be passed, which isn't desired (frontend relies on properties sent in the object, such as a friendly display name, a colour, etc). I have now locked my app to ~2.6.0. If this PR isn't reverted, what can I do to cleanly ensure my loaded state is passed as an object to my SPA (outside of Eloquent resources or Laravel Data, neither of which are being used in my current context)?

[piotrjoniec]

@mikerockett That's strange, because jsonSerialize hasn't changed at all:

https://github.com/spatie/laravel-model-states/blame/main/src/State.php#L259C1-L263C6

But if you want the whole class to be serialized to JSON, wouldn't overriding jsonSerialize like this work?:

    public function jsonSerialize(): mixed
    {
        return $this;
    }

[mikerockett]

@piotrjoniec – my state classes have been implementing that method all along. I think the state caster is taking priority, which is why it's breaking my frontend. I have also played with Arrayable + toArray and Jsonable + toJson to try my luck, but nothing took effect.

[piotrjoniec]

@mikerockett I guess a solution would be to adjust the StateCaster like this:

    public function serialize($model, string $key, $value, array $attributes)
    {
-        return $value instanceof State ? $value->getValue() : $value;
+        return $value instanceof State ? $value->jsonSerialize() : $value;
    }

This way calling toArray and toJson on models would produce consistent results. And overriding jsonSerialize would work as well.

If this makes sense I will submit a PR for this.

[mikerockett]

@piotrjoniec Thanks, I think that’s going to be the best approach. If someone wants different (inconsistent?) behaviour, I guess they could use their own state caster.