Generated GraphQL edges and nodes should be non nullable

[shadiramadan]

In the GraphQL schema, edges and nodes should be made non nullable.

If there are no edges it should be an empty array.
A node should simply not be in the array if it is null so that should also be non-nullable.

• I have searched the issues of this repository and believe that this is not a duplicate.

Summary 💡

Similar to graphql/graphql-relay-js#185

Motivation 🔦

When using codegen on the generated graphql schema (e.g. in Typescript). It becomes frustrating to add tons of boilerplate just to handle nodes or edges not existing in results.

As an example:

return (data.organizations.edges ?? []).map((org) => ({
    organization: org?.node,
    workspaces: (org?.node?.workspaces.edges ?? []).map(
      (workspace) => workspace?.node
    ),
  }));

vs.

return data.organizations.edges.map(({node: org}) => ({
  organization: org,
  workspaces: org.workspaces.edges.map(
    ({node: workspace}) => workspace
  ),
}));