analytics.ts

import * as Functions from "firebase-functions";
import * as Admin from "firebase-admin";
import * as CORS from "cors";
import * as ua from "universal-analytics";

Admin.initializeApp(Functions.config().firebase);

const someProcess = async (request: Functions.Request, response: Functions.Response) => {
  let visitor = ua('UA-XXXXXXXX-X');  // set your Google Analytics account ID
  visitor.pageview({dp: "/someprocess", dt: "SomeProcessExecuted"}).send();
  
  send(response, 200, {
    message: 'Success',
  });
};

function send(response: Functions.Response, statusCode: number, body: any) {
  response.send({
    statusCode,
    headers: { "Access-Control-Allow-Origin": "*" },
    body: JSON.stringify(body),
  });
}

exports.someProcess = Functions.https.onRequest((request, response) => {
  const CORSRequestHandler = CORS({ origin: true });
  CORSRequestHandler(request, response, () => {
    if (request.method !== "POST") {
      send(response, 405, { error: "Invalid Request" });
    }
    try {
      someProcess(request, response)
        .catch(err => {
          console.log(err);
          send(response, 500, {
            error: err.message,
          });
        });
    } catch(e) {
      console.log(e);
      send(response, 500, {
        error: `The server received an unexpected error. Please try again and contact the site admin if the error persists.`,
      });
    }
  });
});