ES CSV export.js

import { saveAs } from 'file-saver';
import { unParse } from 'papaparse';

const HOST = 'https://your-es-domain.com';
const appname = 'your-es-app';
const type = 'your-es-type';

const jsonData = [];
const credentials = "username:password";

// This should be updated by the onQueryChange method on the result component 
const currentQuery = null;


getScrollApiData = (data) => {
    const hits = data.hits.hits;
    jsonData = jsonData.concat(hits);
    let str = null;
    /**
     * Checking if the current data length is less then the total hits from the ES results, 
     * If yes calling the scrollApi function again to fetch the remaining data.
     * 
     * */ 
    if (jsonData.length < data.hits.total) {
      const scrollObj = {
        scroll: '1m',
        scroll_id: data._scroll_id
      };
      scrollApi({ activeQuery: scrollObj, scroll: true, scroll_id: data._scroll_id });
    } else {
      str = JSON.stringify(jsonData, null, 4);
      jsonData = [];
    }
    return str;
  }

  defaultQuery = () => ({ query: { match_all: {} } });

  exportData = () => {
    const defaultQuery = defaultQuery();
    const activeQuery = currentQuery ? currentQuery : defaultQuery;
    scrollApi({ activeQuery });
  };

  /**
   * Param info { activeQuery, scroll, scroll_id }
   */
  scrollApi = (info) => {
    scrollQuery(info.activeQuery, info.scroll, info.scroll_id)
      .then((res) => {
        const data = getScrollApiData(res);
        if (data) {
          try {
            let exportData = JSON.parse(data);
            exportData = exportData.map((value) => {
              const item = Object.assign(value, value._source);
              return flatten(item);
            });

            // Unparsing the data using papaparse package, 
            // A Custom implementation can also be accepted
            const newData = unparse(exportData);
            const file = new File([newData], 'data.csv', { type: 'text/comma-separated-values;charset=utf-8' });
            // Downloading the file using file-saver package
            saveAs(file);
          } catch (e) {
            console.error(e);
          }
        }
      });
  }

  /**
   * A function to convert multilevel object to single level object and use key value pares as Column and row pairs using recursion
   */

  flatten = (data) => {
    const result = {};
    function recurse(cur, prop = '') {
      if (Object(cur) !== cur) {
        result[prop] = cur;
      } else if (Array.isArray(cur)) {
        const l = cur.length;
        for (let i = 0; i < l; i += 1) {
          recurse(cur[i], `${prop}[${i}]`);
        }
        if (l === 0) {
          result[prop] = [];
        }
      } else {
        let isEmpty = true;
        Object.keys(cur).forEach((p) => {
          isEmpty = false;
          recurse(cur[p], prop ? `${prop}.${p}` : p);
        });
        if (isEmpty && prop) {
          result[prop] = {};
        }
      }
    }

    recurse(data);
    return result;
  }

  /**
   * Setting up the query, 
   * If scrollId is defined then it will continue the last scroll call and fetch the next chunk of data.
  */
  scrollQuery = (queryBody, scroll, scrollId) => {
    const createUrl = `${HOST}/${appname}/${type}/_search?scroll=5m`;
    const scrollUrl = `${HOST}/_search/scroll?scroll=5m&scroll_id=${scrollId}`;
    const finalUrl = scroll ? scrollUrl : createUrl;
    return applyQuery(finalUrl, Object.assign({ size: 1000 }, queryBody));
  }


  // Calling the ES using fetch for the given query
  applyQuery = (url, queryBody) => fetch(url, {
    method: 'POST',
    headers: {
      Authorization: `Basic ${btoa(credentials)}`,
      'content-type': 'application/json',
    },
    // credentials: 'include',
    body: JSON.stringify(queryBody),
  }).then(data => data.json());

This is working when I run in Google Chrome. When running with Edge, I am getting error on applyQuery (line 119).
Following is the error coming from Edge:
TypeError: Function expected at Anonymous function (http://localhost:3000/static/js/bundle.js:85606:17)