subscriptionDirectives.js

export class SubscribeDirective extends SchemaDirectiveVisitor {
  visitFieldDefinition(field) {
    field.subscribe = () => pubsub.asyncIterator(field.name);
  }

  visitObject(object) {
    return super.visitObject(object);
  }
}

export class PublishDirective extends SchemaDirectiveVisitor {
  visitFieldDefinition(field) {
    const { to } = this.args;
    const { resolve } = field;
    field.resolve = (...args) => {
      const data = resolve.apply(this, args);
      pubsub.publish(to, { [to]: data });
      return data;
    };
  }

  // This was my attempt to make it work with objects and not just field definitions
  visitObject(object) {
    const { to } = this.args;
    const fields = object.getFields();
    Object.keys(fields).forEach((fieldName) => {
      const field = fields[fieldName];
      const next = field.resolve;

      field.resolve = (result, args, context, info) => {
        pubsub.publish(to, {[to]: result})
        return next(result, args, context, info);
      }
    })
  }
}