Local Abstract Type Settings

[jasonkuhrt]

As mentioned in the docs...

Currently Nexus only supports global abstract type strategy settings. In the future however (#623) there may be ways to enable a particular strategy for only a subset of your schema. This way you could for example express that __typename is required in the returned model data of resolvers for one abstract type but require all other objects whom are members of other abstract types to implement isTypeOf.

Ideally something like:

queryType({
  definition(t) {
    t.field('somethingElse', {
      type: 'SomethingElse',
      // ...
    })

    t.field('search', {
      type: 'SearchResult',
      args: {
        pattern: stringArg(),
      },
      resolve(_, args, ctx) {
        return ctx.db.search(args.pattern).map(result => {
          return {
            ...result,
            __typename: 'Photo', // <-- This property is __REQUIRED__
          }
        })
      },
    })
  },
})

unionType({
  name: 'SearchResult',
  strategy: 'DiscriminantModelField', // <-- Set the strategy only for this abstract type
  definition(t) {
    t.members('Photo' /* ... */)
  },
})

objectType({
  name: 'Photo',
  definition(t) {
    t.string('url')
    t.int('width')
    t.int('height')
  },
})

unionType({
  name: 'SomethingElse',
  strategy: 'Modular', // <-- Set the strategy only for this abstract type
  definition(t) {
    t.members('Thing1', /* ... */)
  },
})

objectType({
  name: 'Thing1',
  isTypeOf(data) { // <-- REQUIRED b/c object is member of "SomethingElse" which uses Modular strategy
    // ...
  },
})