Extending adding field to query

[tobias-f]

Hello.

I am currently try to modify the schema generated from a SDL programatically by adding addition types, directives and so on. Without going too much into detail, I am able to get a reference to the generated schema (GraphQLSchema). Adding directives and types is no problem. However, I want to add also some additional queries to the Query type. I tried the following, but it fails with an exception:

val schema = bean.schema
val extendedQuery = schema.queryType.transform {
  it.field(... adding a field ...)
}

val extendedSchema = schema.transform {
   it.query(extendedQuery)
}                                                        

Caused by: graphql.AssertException: All types within a GraphQL schema must have unique names. No two provided types may have the same name. No provided type may have a name which conflicts with any built in types (including Scalar and Introspection types). You have redefined the type 'Query' from being a 'GraphQLObjectType' to a 'GraphQLObjectType'

Any ideas how I can add additional queries to my schema programmatically?

Thanks a lot.

Cheers,

Tobias

[wasche]

I am running into this as well. I think it might be due to GraphQLSchema.Builder.build() doing schemaUtil.replaceTypeReferences(graphQLSchema); (which looks to be directly altering the types) since we have a reference to the Query object via Mutation.query field. This is currently blocking me, so I will continue my investigation until I have a fix or workaround. My generated schema that I'm transforming is coming via SPQR, if that makes any difference.

[wasche]

I have found a work around for my issue, it appears to only be an issue when using a reference to the Query object, as we allow queries like:

mutation A {
  someMutation {
    field1
  }
  query {
    followOnQuery {
      fieldN
    }
  }
}

And it was the query field on the Mutation object that was causing issues when I was trying to rebuild the schema to add new query/mutation fields. I got around this by re-defining the query field on the Mutation object as a type reference.

FWIW, I have a test against graphql-java that reproduces this issue, but it does seem isolated to refs to the Query object.

[andimarek]

the general problem here is that the GraphQLSchema is an immutable graph with possible cycles. When you want to change it you need to generate a whole new GraphQLSchema graph. This is currently not possible in an easy way, but we are planning to look into that more soon.

[andimarek]

The possibility for easy schema transformations will be available via #1605

[andimarek]

closing this issue now: please have a look at SchemaTransformer and SchemaTransformerTest for how to use the new feature. It will be available in 14.0