Merge remote GraphQL schema into a nested structure

[billxinli]

/label discussion

Assume I have n remote schemas, and I would like to merge the Query, Mutation and Subscription from different schemas into a single schema, except, each remote schema is placed under their own type.

Assume we have a remote schema called MenuX with:

type Item {
  id: Int!
  description: String
  cost: Int
}

type Query {
  items: [Item]
}

and a remote schema called MenuY with:

type Item {
  id: Int!
  name: String
  cost: Int
}

type Query {
  items: [Item]
}

I would like to merge the schema into a single schema but under their own types. A contrived example:

type MenuXItem {
  id: Int!
  description: String
  cost: Int
}

type MenuYItem {
  id: Int!
  name: String
  cost: Int
}

type MenuXQuery {
  items: [MenuXItem]
}

type MenuYQuery {
  items: [MenuYItem]
}

type Query {
  MenuX: MenuXItem
  MenuY: MenuYItem
}

As we can see that under the Query type it contains two new types which contain the query type from the remote schemas. Item from schema MenuX have been renamed by using the transformers from graphql-tools, similarly Item from schema MenuY has been transformed as well.

But is it possible to transform the structure as well?

With the actual remote schemas from Contentful, we are looking at hundreds of types from each schema, and ideally, I would like to not pollute the root types and the Introspection documentation in GraphiQL.

But I think the bigger discussion is what is the standard with merging schemas? Merge in a flat structure or nested structure?

[Atomox]

For reference, you're not the first. See:

• https://stackoverflow.com/questions/46759547/how-to-wrap-a-remote-schema-in-another-query-field
• Make it easy to prevent merging of root query fields #439

It seems others want to go the direction of prefixing the types, but I agree that the root namespace should not be polluted. I've been digging into a way to achieve this locally without a major hack. It seems to me that if we're already mounting remote schemas into our local schema, it should cost us little effort in order to add structure. After all, were we writing this ourselves, we could easily achieve this. There is something to be said for semantic namespacing, which is not only cleaner, but self-documenting.

I would love to see more movement on this.

[yaacovCR]

Solved with WrapType transform. Folded into #1306 .

[yaacovCR]

WrapType would not work for mutations or subscriptions. Best bet would be a spec update that supports namespaces, see graphql/graphql-spec#163