talk/client/coral-framework/services/graphql.js

import { addTypenameToDocument } from 'apollo-client/queries/queryTransform';

/**
 * createGraphQLService
 * @param  {string}  basename  base path of the url
 * @return {Object}  histor service
 */
export function createGraphQLService(registry) {
  return {
    registry,
    resolveDocument(documentOrCallback, props, context) {
      let document =
        typeof documentOrCallback === 'function'
          ? documentOrCallback(props, context)
          : documentOrCallback;
      document = registry.resolveFragments(document);

      // We also add typenames to the document which apollo would usually do,
      // but we also use the network interface in subscriptions directly
      // which require the resolved typenames.
      return addTypenameToDocument(document);
    },
  };
}