Support empty objects during development

[jasonkuhrt]

Perceived Problem

• @nexus/schema will tolerate empty objects
• Empty objects are not valid in a GraphQL schema, at runtime
• They used to be invalid at schema definition time too but that limit was lifted Allow defining empty types graphql/graphql-js#937
• result is makeSchema leads to invalid schemas that won't be caught until runtime

Ideas / Proposed Solution(s)

• @nexus/schema

  • should never produce schemas that will never run

  • fill the empty objects with a placeholder field, e.g.

    object Something {
      """This object is empty in your schema. Nexus has added this field for you. In production [...]"""
      todo: Boolean
    }

  • should expose a way for consumer to configure the field. Should pass some data for consumer to make useful log messages.

    makeSchema({
      on: {
        emptyObject: (object: GraphQLObjectType) => { type: 'remove' } | { type: 'placehold', fieldName?: string, fieldType?: string, heredoc?: string }
      }
    })

  • default: fail in prod, warn in dev

• nexus

  • configure @nexus/schema to placehold during dev but remove and error during prod
  • customize log message to integrate into logger