Interfaces implementing interfaces

[MerzDaniel]

Interface implements Interface of Graphql 15 syntax is not working

We found this issue when trying to implement our type system into graphql. We've got a big set types inheriting properties from common ancestors and all of the ancestors need a common interface so they can be queried.

Expected Behavior

Creating multi inheritance interfaces are working as described in the Graphql spec.

Actual Behavior

When trying to create an interface that implements an interface buildFederatedSchema fails with the error
"Error: Schema must contain uniquely named types but contains multiple types named XXX".

Affected version

• npm: "@apollo/federation": "^0.20.4"

Minimal runnable reproduction

The following type definition fails when creating the federated schema. "Error: Schema must contain uniquely named types but contains multiple types named A"

const { buildFederatedSchema } = require('@apollo/federation')
const { gql } = require('apollo-server-express')


const typeDefs = gql`
  interface A { text: String }
  interface B implements A { text: String number: Int} 
`

const resolvers = {}

buildFederatedSchema([{ typeDefs, resolvers }])

A repository show casing the issue can be found here:
https://github.com/MerzDaniel/apollo-federation-if-impl-if
Just run npm i && npm start

PR introducing the feature

#30

[nikolayandr]

Is this issue solved now according to closed provided PR?

[teovillanueva]

Hey! quick question! Is this fixed?