GraphQL Java Kickstart Tools Enums causing exception - Expected enum with name 'XXX' but found none

Question

How is a Java enum correctly registered with GraphQL when using the kickstart framework with spring?

In attempting to use a GraphQL schema enum with an equivalent Java enum in a simple Java Spring application, the following exception is thrown:

Caused by: graphql.kickstart.tools.SchemaError: Expected enum with name 'CarType' but found none!
at graphql.kickstart.tools.SchemaParser.createEnumObject(SchemaParser.kt:191)
at graphql.kickstart.tools.SchemaParser.parseSchemaObjects(SchemaParser.kt:85)
at graphql.kickstart.tools.SchemaParser.makeExecutableSchema(SchemaParser.kt:112)
at graphql.kickstart.tools.boot.GraphQLJavaToolsAutoConfiguration.graphQLSchema(GraphQLJavaToolsAutoConfiguration.java:147)
at graphql.kickstart.tools.boot.GraphQLJavaToolsAutoConfiguration$$EnhancerBySpringCGLIB$$1b4eddf2.CGLIB$graphQLSchema$1(<generated>)

How is the Java side enum class registered? I've seen examples with RuntimeWiring and registering them via this but the schema creation is done automatically for my usage so I cannot find a way (or the correct hook) to achieve this.

The GraphQL schema is:

extend type Query {
    cars : [Car]
}

type Car {
    type : CarType
}

enum CarType {
    AUDI,
    BMW,
    VOLKSWAGEN
}

And the Java enum:

public enum CarType {
    AUDI, BMW, VOLKSWAGEN
}

Answer 1

So in the code I didn't post, I was deliberately using a HashMap instead of a Dto pojo class with the enum residing inside:

public class CarsResolver implements GraphQLQueryResolver {
    public Collection<HashMap> cars() {
        return emptyList();
    }
}

This meant (I think) that the class in the collection wasn't ever traversed by the framework to create the resolver for the enum auto-magically... this resulted in the above exception.

The reason (by the way) I was deliberately using a HashMap was to avoid a generic graphql gateway from knowing about the Dto types in our broader system. I am now rethinking this decision :-)