using messenger HandleTrait as QueryBus with appropriate result typing

[bnowak]

This PR goal is to determine correct result typing for QueryBus kind of classes which uses SF messenger HandleTrait internally and simply return its results.

[michaljusiega]

@ondrejmirtes Sorry to disturb you, but I think this is one of the pieces that is missing in this whole puzzle to support. Can we move forward ?

[bnowak]

Hi @michaljusiega, thanks for your reply. I think we can add it - no problem. However, from my perspective it's more important to address the root issue (missing feature) of the topic (described here). My reasoning is without having this result interpreted on bus class level - this is much less useful in general.

[ondrejmirtes]

So this QueryBus class is something in your codebase and you want the same type inference that classes using HandleTrait and calling the handle method have?

You can simply write a dynamic return type extension for QueryBus::dispatch() that delegates the type resolution to new MethodCall($methodCall->var, 'handle', $methodCall->getArgs()).

[bnowak]

@ondrejmirtes It's ready for review now. You were right about my intentions, however I wanted to make it working for any class that uses HandleTrait internally. I didn't want to hardcoded it, so made it parameterized. I've added also support for interfaces. Please review in you free time :pray:

It's likely to be conflicted with my another PR about splitting tests, so once first of these PR will be merged I can resolve conflicts on another one. :wink:

[bnowak]

@ondrejmirtes any chances to review & merge it soon, please? :)