Future[T] and Promise[T] as Controller ReturnTypes

[domdorn]

This PR adds support for Future[T] and Promise[T] as return types in resources, e.g.

@Path("/")
class GreetingResource() 
    @GET
    @Path("/greet/promise")
    def promiseGreeting(): Promise[String] =
      Promise.successful("Hello from the promise")
    end promiseGreeting
end GreetingResource

I also added tests in the integration module and converted them to be in Scala

[domdorn]

I've reworked this PR so that everything that resolves around using Future[T] or Promise[T] is in it own sub-extension. In another PR I'll add support for ZIO[R,E,A] in the same manner.

[gsmet]

Thanks for the PRs, it's nice to see some activity in this project.

I added some suggestions, some of them minor, some of them not so much :).

[gsmet]

BTW, I suggest we get this one in shape and merged, before applying the same changes to the ZIO PR.

[gsmet]

Disclaimer: I have no knowledge of Scala, so please don't hesitate to push back if what I say doesn't make sense :).

BTW, I think you could put everything in the same module.

The build item machinery should be clever enough to not trigger the loading of the classes you added if the Quarkus REST extension is not around.
My guess is that you could simplify the integration by having the SPI dependencies around but quarkus-rest would be an optional dependency.

I think that would have my preference if you can make it work as the experience will be better for the users.

[domdorn]

@gsmet I've updated the PR, please have a look. I noticed that I don't get the stack trace in the native executable in case of an error, so I removed the check on the body (in the tests).
I had everything in the same extension but when adding the zio one I figured it would be cleaner to have it in its own extension, especially if one day we'll add other effect types (cats/monix/whatever) as well..

[carlosedp]

Hey folks, any news on this?

[domdorn]

I think I've applied everything that was requested, but maybe I missed something.
Anyways, I'm going to be on holidays the next 3 weeks without spare time to work on this.
From my point of view, the potentially remaining issues are just about moving code to the right places.
If anyone wants to fork/take over the PR, please do so!

[carlosedp]

@domdorn I think it's pretty good! We just need to wait review from @gsmet ... he might be pretty busy with recent Quarkus release.

Maybe Guillaume needs some help on maintaining this repo too... :)