Handler ES5

handler_es5.js

const logger = require("firebase-functions/logger") // Optional logger from Firebase.

async function handler(params) {
  return new Promise(async (resolve, reject) => {
    try {
      // Code here ...
      
      return resolve();
    } catch (err) {
      logger.warn("something wrong in handler", err);
      return reject(err);
    }
  });
}

module.exports = handler;