feat: field extensions

[n1ru4l]

type GraphQLExtensions = {
  field: {
    liveQuery?: {
      collectResourceIdentifiers: (
        src: any,
        args: any
      ) => Iterable<string> | string | null;
    };
  };
};

export const t = createTypesFactory<GraphQLContextType, GraphQLExtensions>();

t.field("note", {
  type: GraphQLNoteType,
  args: {
    documentId: t.arg(t.NonNullInput(t.ID))
  },
  extensions: {
    liveQuery: {
      collectResourceIdentifiers: (_: any, args: any) =>
        `Note:${args.documentId}`
    }
  },
  resolve: (_, args, context) => RT.run(resolveNote(args.documentId), context)
});

This allows typing the available extensions for t.field and t.objectType. I have not figured out whether it would be possible to also make the arguments of the extensions field depending on the provided arguments. For E.g. my liveQuery.collectResourceIdentifiers implementation always calls the function with the source object and the args. However other extensions could do something completely different. @sikanhe Please let me know what you think.

[sikanhe]

On the first look it seems like it requires some kind of Higher Kinded Typing to make possible...

[n1ru4l]

I guess the higher typing (if even possible) could always be introduced at a later point. @sikanhe Any more feedback on this? Could we merge and ship this?

[sikanhe]

@n1ru4l looks good with me