Rest Client disable-default-mapper not working properly

[Serkan80]

Describe the bug

It seems that disable-default-mapper for the rest client only works when you map the endpoint's return type with a Response or RestResponse. All other options don't work.

Example:

@Path("/api/fruit")
@RegisterRestClient(configKey = "fruitivy", baseUrl = "https://www.fruityvice.com")
public interface FruitivyDirectClient {

    @GET
    @Path("/{name}")
    Response findByName(String name);   // ----------> disable-default-mapper works 

    @GET
    @Path("/{name}")
    RestResponse<Fruit> findByName2(String name);   // ----------> disable-default-mapper works


    @GET
    @Path("/{name}")
    Fruit findByName3(String name);   // ----------> disable-default-mapper does not work it throws an error
}

Expected behavior

the disable-default-mapper should work for any return type.

Actual behavior

No response

How to Reproduce?

set quarkus.rest-client."fruitivy".disable-default-mapper=true and then call:

var response = this.client.findByName3("banana2"); 

this code should return null, but it throws an exception

Output of uname -a or ver

No response

Output of java -version

21

Quarkus version or git rev

3.28.2

Build tool (ie. output of mvnw --version or gradlew --version)

Maven

Additional information

No response

[quarkus-bot]

/cc @cescoffier (rest-client), @geoand (rest-client)

[Serkan80]

And I'm not sure whether I should say this in this thread, but it would also be very nice if Optional was also supported as a return type for the rest clients.

[geoand]

That's expected because there is no real general way to convert the result into the type you need.