A recursive function calling AppSyncClient GraphQL requests for ReactNative apps

fetchItemsNextToken.js

import { Logger } from 'aws-amplify';

const logger = new Logger('fetchItemsNextToken', 'VERBOSE');

/**
 * @desc Recursively fetch all items in a list query using nextToken
 * @param {Object} client An AppSyncClient instantiation
 * @returns {Object} { items, key } Items are results,
 *  key is the name of the query called.
 */
function getFullFetch(client) {
  /**
   *
   * @param {*} query Query gql document
   * @param {*} variables Query vars
   * @param {array} items Returned items
   * @param {String} fetchPolicy The chosen fetch-policy, from Apollo Client.
   */
  const fetchItemsNextToken = async ({
    query,
    variables,
    items = [],
    fetchPolicy = 'cache-first',
  }) => {
    try {
      const { data } = await client.query({ query, variables, fetchPolicy });
      if (!data) return items;

      const key = Object.keys(data).find(k => k.includes('list'));

      if (!key) return items; // just in case error handling

      const res = data[key]; // res = { items: [], nextToken: '' }

      // To handle cases of listScopesByGroup and others that don't have Connection (...items) objects
      if (res.items) items.push(...res.items);
      else items.push(...res);

      if (!res.nextToken) return items;

      // eslint-disable-next-line no-param-reassign
      variables.nextToken = res.nextToken;
      return fetchItemsNextToken({ query, variables, items, fetchPolicy });
    } catch (err) {
      logger.error(err);
      return items;
    }
  };
  return fetchItemsNextToken;
}

export default getFullFetch;