After upgrading to mapstruct 1.4.1 we are having some problems with mapping collections using named mapping methods. I suspect this is a bug b/c it worked fine for mapstruct 1.2.0.

The full example can be found here: https://gist.github.com/MaciejDobrowolski/6a9b9bedfd873e8ffd822301ab333be4

I am getting the following errors:

Demo.java:36: error: Qualifier error. No method found annotated with @Named#value: [ fromBase ]. See https://mapstruct.org/faq/#qualifier for more info.
House toEntity(HouseDto houseDto);
^
Demo.java:36: error: Can't map property "List dogs" to "List dogs". Consider to declare/implement a mapping method: "List map(List value)".
House toEntity(HouseDto houseDto);
^

+short in-ticket summary:

Having the following model:

class BaseEntity {
    private Long id;
}

class Dog extends BaseEntity {
    private String name;
}

class House extends BaseEntity {
    private List<Dog> dogs;
}

class BaseDto {
    private Long id;
}

class HouseDto extends BaseDto {
    private List<BaseDto> dogs;
}

And the following mapper:

@Named("fromBase")
public <T> T fromBase(BaseDto baseDto, @TargetType Class<T> entityClazz) {
    return Optional.ofNullable(baseDto)
            .map(BaseDto::getId)
             // somehow create instance of T from id
            .orElse(null);
}

The above mapper is not used by the one below:

@Mapping(target = "dogs", qualifiedByName = "fromBase")
House toEntity(HouseDto houseDto);

If I only change dogs to be a single dog (without List), it works as expected.

update: I have just removed generics and @TargetType from fromBase mapping method and it still returns the same error