Add to Calendar Urls in Eleventy

.eleventy.js

const { google, outlook, office365, yahoo, ics } = require("calendar-link");

module.exports = function(eleventyConfig) {
  // `event` structure documented on https://www.npmjs.com/package/calendar-link
  eleventyConfig.addLiquidFilter("addToCalendar", (event, type) => {
    if(type === "google") {
      return google(event);
    } else if(type === "office365") {
      return office365(event);
    } else if(type === "outlook") {
      return outlook(event);
    } else if(type === "ics") {
      return ics(event);
    }

    throw new Error(`Invalid type (${type}) received in addToCalendar filter.`);
  });
};