How to create a CSV file using a script

Scenario.

Create a CSV file using a script with two columns of Tax Code and Rate.

let titleArray = ["Tax Code", "Rate"];
let csvFileData = titleArray.toString() + '\r\n';
 summaryContext.output.iterator().each((key, value) => {

                    let parseSummary = JSON.parse(value);
                    let zipCode = parseSummary.zipCode;
                    let rate = parseSummary.rate
                    csvFileData += zipCode + ',' + rate + '\n'
                    return true;
                });
 let fileObj = file.create({
                    name: 'ZIPCODES-AND-RATE-' + Math.floor(Date.now() / 1000) + '.csv',
                    fileType: file.Type.CSV,
                    contents: csvFileData

                });

This fileObj can be either saved in a folder in the file cabinet or it can be send as a CSV file attachment.