Fix/transform schema interfaces implementing interfaces

[m4rw3r]

This PR fixes apollographql/federation#227

TODO:

• Update CHANGELOG.md* with your change (include reference to issue & this PR)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

*Make sure changelog entries note which project(s) has been affected. See older entries for examples on what this looks like.

[apollo-cla]

@m4rw3r: Thank you for submitting a pull request! Before we can merge it, you'll need to sign the Apollo Contributor License Agreement here: https://contribute.apollographql.com/

[noam-c]

Hi folks! I just wanted to see if this PR is going to still be merged -- my team has run into apollographql/federation#227 in our use case and it would be great to have that fixed so we could make use of interface inheritance.

[DanielSinclair]

Bumping this issue. This functionality is officially recognized and was merged into the the GraphQL Specification on Jan 10, 2020. See here. This pattern is particularly helpful for reducing downstream implements Node statements for the Connection pagination pattern:

type UserContactsConnection {
  pageInfo: PageInfo!
  edges: [UserContactsEdge]
}

type UserContactsEdge {
  cursor: String!
  node: Contact
}

interface Contact implements Node {
  id: ID!
  type: ContactType!
  name: String
}

enum ContactType {
  FRIEND
  COWORKER
}

type Friend implements Contact {
  id: ID!
  type: ContactType!
  name: String
  bestFriend: Boolean
}

type Friend implements Contact {
  id: ID!
  type: ContactType!
  name: String
  company: Company
}

[TomB15]

Hi, is there any progress on this issue? I would like to support merging this change.

[deodad]

Apollo team -- anything the community can do to help here? Can re-open PR with the contributor license signed if that would help.

[m4rw3r]

I did sign the CLA way back, and tests pass locally, the circleci test seems to have failed for some unrelated reason. I guess a rebase could help?

[deodad]

I did sign the CLA way back, and tests pass locally, the circleci test seems to have failed for some unrelated reason. I guess a rebase could help?

worth a shot!

[m4rw3r]

The Windows test is still failing despite rebase, due to the wrong NodeJS version being installed:

#!powershell.exe -ExecutionPolicy Bypass
if ((node --version) -Ne "v${Env:NODE_VERSION}") { exit 1 }


Exited with code exit status 1

CircleCI received exit code 1

The actual used version used above seems to be v14.17.5: https://app.circleci.com/pipelines/github/apollographql/apollo-tooling/12104/workflows/2ed184d5-e5ba-4104-9dea-600b5def5c79/jobs/137143/parallel-runs/0/steps/0-102

But the successful test on master uses v14.16.1: https://app.circleci.com/pipelines/github/apollographql/apollo-tooling/12055/workflows/7b62fcba-3c52-4ee2-8a5d-24a399209fc5/jobs/136772/parallel-runs/0/steps/0-102

[hwillson]

Thanks for this @m4rw3r - this ended up being resolved in #2456 so I'll close this off.