[relay-compiler] Compiler doesn't work for connections when types are non-nullable

[nikolasburk]

I'm having an issue with the relay-compiler that fails when fields are required.

Here's a simplified version of the schema that I used when I was hitting the issue.

allPosts(after: String, before: String, first: Int, last: Int): PostConnection!

type PostConnection {
  pageInfo: PageInfo!
  edges: [PostEdge]
}

type PostEdge {
  node: Post!
  cursor: String!
}

type PageInfo {
  hasNextPage: Boolean!
  hasPreviousPage: Boolean!
  startCursor: String
  endCursor: String
}

type Post {
  id: ID!
  title: String!
}

Using required fields on the connections caused the compiler to fail with the following error:

Invariant Violation: RelaySchemaUtils: Expected type `PostConnection!` to be an object or interface type.

Using the following schema without required fields works:

allPosts(after: String, before: String, first: Int, last: Int): PostConnection

type PostConnection {
  pageInfo: PageInfo
  edges: [PostEdge]
}

type PostEdge {
  node: Post
  cursor: String
}

type PageInfo {
  hasNextPage: Boolean
  hasPreviousPage: Boolean
  startCursor: String
  endCursor: String
}

type Post {
  id: ID!
  title: String!
}

Feel free to take a look at the full project (note that the README doesn't yet include instructions about setting up the relay-compiler).

[kassens]

If you want to take a look, the cause is most likely in RelayConnectionTransform.validateConnectionType.

Adding a new connection to the test schema that's non-nullable to extend the test in RelayConnectionTransform-test.js would be great!

[nikolasburk]

Hey Jan, thanks for thee hint! This seems like a slightly bigger refactor since assertTypeWithFields is used in multiple places, I'm not really comfortable doing that right now. I'll be releasing a getting started tutorial about Relay Modern today where I adjust the schema and remove the constraint for certain fields to be required in order to work around the issue.

[nikolasburk]

FYI - the tutorial is now online: https://www.graph.cool/docs/tutorials/relay-modern-getting-started-woodito7ug

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.