This project demonstrates apollo code gen.
The schema is located at APISchema/schema.graphqls directory.
There is only one query node that fetches Node interface. There's a few implementations of Node.
There is a single Node query that fetches NodeFragment. The fragment contains fragments for other nodes.
You need to point to your local checkout of apollographql/apollo-ios-dev#307 for this to work since it uses fields getting introduced in the PR.
You can run code gen using swift run codegen which executes the code gen command located at Sources/codegen/Command.swift