@shko.online/dataverse-odata/lib/esm/getTopFromParser.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';
import { hasContent } from './validators/hasContent';
const option = '$top';

/**
 * Parses the {@link ODataTop.$top $top} query
 * @returns Returns `false` when the parse has an error
 */
export const getTopFromParser = (parser, result) => {
  const value = parser.getAll(option);
  if (value.length === 0) {
    return true;
  }
  if (!atMostOnce(option, value, result) || !hasContent(option, value, result)) {
    return false;
  }
  let $top;
  if (!value[0].match(/^\d+$/) || ($top = parseInt(value[0])) < 0) {
    result.error = {
      code: '0x0',
      message: `Invalid value '${value}' for $top query option found. The $top query option requires a non-negative integer value.`
    };
    return false;
  } else if ($top === 0) {
    result.error = {
      code: '0x0',
      message: `Invalid value for $top query option.`
    };
    return false;
  }
  result.$top = $top;
  return true;
};