Example and schema of response is empty while using abstract generic

[baxol]

Describe the bug
While defining the controller as an abstraction and using generic as a response, the example and schema in the swagger are empty.

To Reproduce
I have generic controller to provide crud methods as follows:

abstract class BaseCrudController<T, E : BaseEntityModel>(private val baseCrudService: BaseCrudService<T, E>) {
    ...
    @GetMapping("/{sid}")
    open fun read(@PathVariable sid: String): Mono<ResponseEntity<T>> =
            baseCrudService.read(sid)
                    .map { ResponseEntity.ok().body(it) }
                    .defaultIfEmpty(ResponseEntity.notFound().build())
    ...
}

and this is used in User controller implementation:

@RestController
@RequestMapping("api/import/user")
class UsrController(userService: UserService) :
        BaseCrudController<User, UserEntity>(userService)

User class contains the definition of swagger schema:

data class User(
        @get:Schema(
                title = "Speaking Id of User",
                pattern = Pattern.speakingId,
                example = "newUser"
        )
        val sid: String
)

Expected behavior
I should see the example and schema. In version 1.4.4 it still not works.

Additional context
I found if I define result differently then it works:
Mono<ResponseEntity<T>> -> Mono<T>
but in this case, I am losing the possibility to control response, I mean I have to control it differently (by exception handler).

Also if this controller is not defined as abstract the definition of endpoints are under a class with @RestController the
Mono<ResponseEntity<User>> works like a charm.

[bnasslahsen]

@baxol,

Not sure that there is any standard spring API that can achieve your goal: GenericTypeResolver.resolveType, doesn't seem to handle your case of nested generics.

I have added a fix to to handle this case. You can please validate this fix with the latest SNAPSHOT?
Here is the link to configure the snapshots:

• https://springdoc.org/faq.html#how-can-i-use-the-last-springdoc-openapi-snapshot-

I have you any proposal to improve the management of this case, please feel free to propose.