@shko.online/dataverse-odata/lib/modern/getSelectFromParser.js

This package will help parse OData strings (only the Microsoft Dataverse subset). It can be used as a validator, or you can build some javascript library which consumes the output of this library.

import { atMostOnce } from './validators/atMostOnce';
const option = '$select';

/**
 * Parses the {@link ODataSelect.$select $select} query
 * @returns {boolean} Returns `false` when the parse has an error
 */
export const getSelectFromParser = (parser, result) => {
  const value = parser.getAll(option);
  if (value.length === 0) {
    return true;
  }
  if (!atMostOnce(option, value, result)) {
    return false;
  }
  if (value.length > 0) {
    result.$select = value[0].split(',');
  }
  return true;
};