ES6+ in Cloud Functions for Firebase - preset-2015,2016,2017 to compile async/await

CF4F-ES6-2|function04.js

// Babel output - with Babel REPL settings:
// * prettify
// * preset-es2015 (es6->es5)
// * preset-es2016 (es7->es6)
// * preset-es2017 (es8->es7)

"use strict";

function _asyncToGenerator(fn) {
  return function() {
    var gen = fn.apply(this, arguments);
    return new Promise(function(resolve, reject) {
      function step(key, arg) {
        try {
          var info = gen[key](arg);
          var value = info.value;
        } catch (error) {
          reject(error);
          return;
        }
        if (info.done) {
          resolve(value);
        } else {
          return Promise.resolve(value).then(
            function(value) {
              step("next", value);
            },
            function(err) {
              step("throw", err);
            }
          );
        }
      }
      return step("next");
    });
  };
}

var functions = require("firebase-functions");

// returns a string after 5 seconds
var message = function message() {
  return new Promise(function(resolve) {
    setTimeout(function() {
      resolve("from Babelified Cloud Functions!");
    }, 5000);
  });
};

module.exports.helloWorld = functions.https.onRequest(
  (function() {
    var _ref = _asyncToGenerator(
      /*#__PURE__*/ regeneratorRuntime.mark(function _callee(req, res) {
        var world;
        return regeneratorRuntime.wrap(
          function _callee$(_context) {
            while (1) {
              switch ((_context.prev = _context.next)) {
                case 0:
                  _context.next = 2;
                  return message();

                case 2:
                  world = _context.sent;

                  res.status(200).send("Hello " + world);

                case 4:
                case "end":
                  return _context.stop();
              }
            }
          },
          _callee,
          undefined
        );
      })
    );

    return function(_x, _x2) {
      return _ref.apply(this, arguments);
    };
  })()
);