I am trying to create a custom directive that do some transform/validation on input type in GraphQL DGS in Java Spring Boot
Here is how I declare my custom directive

directive @trim on FIELD_DEFINITION | INPUT_FIELD_DEFINITION

type Subscriber {
    id: ID
    name: String @trim
    email: String @trim
}

input SubscriberInput {
    name: String @trim
    email: String @trim
}

Thing working fine for @trim on type Subscriber as I declare @DgsDirective(name = "trim") in my code

@DgsDirective(name = "trim")
public class TrimDirective implements SchemaDirectiveWiring {

    @Override
    public GraphQLFieldDefinition onField(SchemaDirectiveWiringEnvironment<GraphQLFieldDefinition> env) {
        GraphQLObjectType fieldsContainer = (GraphQLObjectType) env.getFieldsContainer();
        GraphQLFieldDefinition fieldDefinition = env.getFieldDefinition();
        DataFetcher<?> originalDataFetcher = env.getCodeRegistry().getDataFetcher(fieldsContainer, fieldDefinition);
        DataFetcher<?> dataFetcher = DataFetcherFactories.wrapDataFetcher(
                originalDataFetcher,
                (dataFetchingEnvironment, value) -> {
                    if (value instanceof String) {
                        return ((String) value).trim();
                    }
                    return value;
                });

        env.getCodeRegistry().dataFetcher(fieldsContainer, fieldDefinition, dataFetcher);
        return fieldDefinition;
    }
}

However when I try to override onInputObjectField for input type SubscriberInput it is not working as env.getFieldsContainer() and env.getFieldDefinition() return null.

How can I achieve same result as onField with onInputObjectField. Thanks.