@windingtree/wt-search-api/src/services/query-parser/index.js

NodeJS app that enables quick search over data from Winding Tree platform

const byCategory = require('./indices/by-category');
const byDefaultLocale = require('./indices/by-default-locale');
const byLocation = require('./indices/by-location');
const { QueryParseError } = require('./errors');

const FILTERS = {
  // { <query_param> : <filter_fn> }
  category: byCategory.getFilter,
  location: byLocation.getFilter,
  defaultLocale: byDefaultLocale.getFilter,
};

const SORTS = {
  // { <query_param> : <sort_fn> }
  sortByDistance: byLocation.getSort,
};

/**
 * Extract filtering information from the GET query and
 * transform it to the internal representation.
 *
 * @param {Object} query request GET params
 * @return {Array}
 * @throw QueryParseError
 *
 */
function getFilters (query) {
  const filters = Object.keys(FILTERS)
    .map((filterParam) => {
      if (!query[filterParam]) {
        return;
      }
      return FILTERS[filterParam](query[filterParam]);
    })
    .filter(Boolean)
    .reduce((prev, curr) => prev.concat(curr), []);

  return (filters.length > 0) ? filters : undefined;
}

/**
 * Extract sorting representation from the GET query, if
 * applicable.
 *
 * @param {Object} query request GET params
 * @return {Object}
 * @throw QueryParseError
 *
 */
function getSort (query) {
  return Object.keys(SORTS)
    .map((sortParam) => {
      if (!query[sortParam]) {
        return;
      }
      return SORTS[sortParam](query[sortParam]);
    })
    .filter(Boolean)
    .reduce((prev, curr) => {
      if (prev && curr) {
        throw new QueryParseError('Cannot specify more than a single criteria for sorting.');
      }
      return prev || curr;
    }, undefined);
}

module.exports = {
  FILTERS,
  SORTS,
  QueryParseError,
  getFilters,
  getSort,
};