Exception in thread "main" java.lang.ExceptionInInitializerError
	at guide.reference.graphql.TmpKt.main(Tmp.kt:32)
	at guide.reference.graphql.TmpKt.main(Tmp.kt)
Caused by: com.expediagroup.graphql.generator.exceptions.EmptyQueryTypeException: Invalid query object type - no valid queries are available.

toSchema(queries=)

Caused by: com.expediagroup.graphql.generator.exceptions.EmptyQueryTypeException: Invalid query object type - no valid queries are available.

object MyGraphQLHandler : GraphQLHandler {
    private val graphQL = newGraphQL(
        toSchema(
            SchemaGeneratorConfig(supportedPackages = listOf("guide.reference.graphql")),
            listOf(TopLevelObject(UserQuery())),
            listOf()
        )).build()

    override fun invoke(request: GraphQLRequest) = GraphQLResponse.from(graphQL.execute(request.query))
}

data class User(val name: String, val email: String)

class UserQuery {
    fun create(name: String): User = User(name, "$name@$<http://name.com|name.com>")
}

fun main() {
    val app: HttpHandler = routes(
        "/graphql" bind graphQL(MyGraphQLHandler)
    )

    // serve GQL queries/mutations at /graphql
    val server = app.asServer(SunHttp(8000)).start()

    // for clients, just convert any app into a GQL handler
    val gql: GraphQLHandler = JavaHttpClient().asGraphQLHandler(Uri.of("<http://localhost:8000/graphql>"))
    val response: GraphQLResponse = gql(GraphQLRequest(" { create(name: \"Tom\") { email } }"))
    println(response)
}
}