@ConvertWith in Map value type parameter is not working

[radcortez]

Something like this should work:

@ConfigMapping(prefix = "map")
public interface MapOfList {
    Map<String, @WithConverter(ListConverter.class) List<String>> map();
}

But it got broken when the Collection support was added because now the Map value type is mapped as a CollectionProperty and does not take the Converter into account.

[radcortez]

Unfortunately, due to https://github.com/oracle/graal/issues/3671, the proposed solution does not work in native mode.

Also, there are some substitutions in Quarkus that also affect this: https://github.com/quarkusio/quarkus/blob/8bb206d35aff8cb3c9f7c72c9938685f3d6fb85d/core/runtime/src/main/java/io/quarkus/runtime/graal/MethodReplacement.java#L13 https://github.com/oracle/graal/issues/650

Most likely we can get rid of that, but not before a fix for https://github.com/oracle/graal/issues/3671.

[marcelstoer]

Just to give more context to casual observers, this started at https://quarkusio.zulipchat.com/#narrow/stream/187030-users/topic/Config.20mapping.20a.20map.20of.20lists.

[marcelstoer]

I guess it's now time to revisit this as the Graal blocker was apparently fixed with 22.1.

[radcortez]

I'll have a look.