Get public events from a subscribed Meetup Google calendar ics ical file

meetup.ts

import fetch from 'node-fetch';

interface Events {
  startTime: Date;
  endTime: Date;
  url: string;
  description: string;
  location: string;
  title: string;
  id: string;
}

enum DateTZIdx {
  T = 8,
  Z = 15,
}

const parseDate = (date: string): Date => {
  const year = parseInt(date.substr(0, 4));
  const month = parseInt(date.substr(4, 2), 10) - 1;
  const day = parseInt(date.substr(6, 2));
  const hour = parseInt(date.substr(9, 2));
  const minute = parseInt(date.substr(11, 2));
  const second = parseInt(date.substr(13, 2));
  return new Date(Date.UTC(year, month, day, hour, minute, second));
};

const validateDate = (val: string): boolean => {
  if (val.length !== 16) return false;
  if (val[DateTZIdx.T] !== 'T') return false;
  if (val[DateTZIdx.Z] !== 'Z') return false;
  val
    .split('')
    .filter((nums, i) => nums !== DateTZIdx[i])
    .every((num) => !isNaN(parseInt(num)));
  return true;
};

const main = async () => {
  const result = await fetch(
    'https://calendar.google.com/calendar/ical/<YOUR GOOGLE CALENDAR ID>/public/basic.ics'
  );
  const data = await result.text();
  const dataArr = data.split('\r\n');
  const event: { [key: string]: unknown } = {};
  const events: {}[] = [];
  const eventMap: { [key: string]: string } = {
    DTSTART: 'startTime',
    DTEND: 'endTime',
    URL: 'url',
    DESCRIPTION: 'description',
    LOCATION: 'location',
    SUMMARY: 'title',
    UID: 'id',
  };
  dataArr.forEach((line: string) => {
    const colon = line.indexOf(':');
    let key, value;
    [key, value] = [line.slice(0, colon), line.slice(colon + 1)];
    if (key === 'END') {
      events.push({ ...event });
    } else if (eventMap.hasOwnProperty(key)) {
      if(validateDate(value)) value = parseDate(value)
      event[eventMap[key]] = value as unknown as Events;
    }
  });
  console.log(events);
  return events;
};

main();
console.log(parseDate('20210925T123000Z'));
console.log(parseDate('20210925T143000Z'));