Possibility to add __typename to response projection of GraphQL types

[jxnu-liguobin]

Is your feature request related to a problem? Please describe.
I think if model is a interface or them subclass always need __typename to deserialized

this is successfully

  def hero(episode: EpisodeDO): CharacterDO = {
    val heroQueryRequest = new HeroQueryRequest
    heroQueryRequest.setEpisode(episode)
    //must use typename, and add jackson annotation to support
    val characterResponseProjection = new CharacterResponseProjection().id().name().typename()
      .friends(new CharacterResponseProjection().id().typename()).appearsIn()
    val graphQLRequest = new GraphQLRequest(heroQueryRequest, characterResponseProjection)
    val retFuture = OkHttp.executeRequest(graphQLRequest, new TypeReference[CharacterDO] {})
    val ret = Await.result(retFuture, Duration.Inf)
    ret
  }

this is failed

  def droid(id: String): DroidDO = {
    val productByIdQueryRequest = new DroidQueryRequest
    productByIdQueryRequest.setId(id)
    val droidResponseProjection = new DroidResponseProjection().id().name()
    val graphQLRequest = new GraphQLRequest(productByIdQueryRequest, droidResponseProjection)
    val retFuture = OkHttp.executeRequest(graphQLRequest, new TypeReference[DroidDO] {})
    val ret = Await.result(retFuture, Duration.Inf)
    ret
  }

msg

com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [simple type, class io.github.dreamylost.model.DroidDO]: missing type id property '__typename'
 at [Source: (String)"{"name":"R2-D2","id":"2001"}"; line: 1, column: 28]

config

customAnnotationsMapping := {
  val mapping = new util.HashMap[String, String]
  //must add this annotation
  //property is __typename and you must with __typename while invoke, like new CharacterResponseProjection().id().name().typename()
  //and in @JsonSubTypes.Type, name is __typename's value
  mapping.put("Character",
    """com.fasterxml.jackson.annotation.JsonTypeInfo(use=com.fasterxml.jackson.annotation.JsonTypeInfo.Id.NAME, include=com.fasterxml.jackson.annotation.JsonTypeInfo.As.PROPERTY,property = "__typename")
      |@com.fasterxml.jackson.annotation.JsonSubTypes(value = {
      |        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = HumanDO.class, name = "Human"),
      |        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = DroidDO.class, name = "Droid")
      |})
      |""".stripMargin)
  mapping
}

java class

package io.github.dreamylost.model;


@javax.annotation.Generated(
    value = "com.kobylynskyi.graphql.codegen.GraphQLCodegen",
    date = "2020-07-21T09:54:54+0800"
)
@com.fasterxml.jackson.annotation.JsonTypeInfo(use=com.fasterxml.jackson.annotation.JsonTypeInfo.Id.NAME, include=com.fasterxml.jackson.annotation.JsonTypeInfo.As.PROPERTY,property = "__typename")
@com.fasterxml.jackson.annotation.JsonSubTypes(value = {
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = HumanDO.class, name = "Human"),
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = DroidDO.class, name = "Droid")
})

public interface CharacterDO {

    @javax.validation.constraints.NotNull
    String getId();

    @javax.validation.constraints.NotNull
    String getName();

    @com.fasterxml.jackson.annotation.JsonTypeInfo(use=com.fasterxml.jackson.annotation.JsonTypeInfo.Id.NAME, include=com.fasterxml.jackson.annotation.JsonTypeInfo.As.PROPERTY,property = "__typename")
@com.fasterxml.jackson.annotation.JsonSubTypes(value = {
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = HumanDO.class, name = "Human"),
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = DroidDO.class, name = "Droid")
})

    java.util.List<? extends CharacterDO> getFriends();

    @javax.validation.constraints.NotNull
    java.util.List<EpisodeDO> getAppearsIn();

    @Deprecated
    String getSecretBackstory();

}

because i can not use typename on DroidResponseProjection

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Describe alternatives you've considered
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Additional context
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[kobylynskyi]

@jxnu-liguobin, if I understand the problem correctly, we need to add __typename to all types always?

[jxnu-liguobin]

yes, If a class has an inheritance structure (not java.lang.object), __typename must required

[jxnu-liguobin]

Hi, multiple annotations can be aligned? after string append, the annotations on the field are not aligned and have a empty line, but on the class is aligned,

    @com.fasterxml.jackson.annotation.JsonTypeInfo(use=com.fasterxml.jackson.annotation.JsonTypeInfo.Id.NAME, include=com.fasterxml.jackson.annotation.JsonTypeInfo.As.PROPERTY,property = "__typename")
@com.fasterxml.jackson.annotation.JsonSubTypes(value = {
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = HumanDO.class, name = "Human"),
        @com.fasterxml.jackson.annotation.JsonSubTypes.Type(value = DroidDO.class, name = "Droid")
})