a.js

import 'regenerator-runtime/runtime';
import Promise from 'bluebird';

function doSomethingAsync(value) {
	return new Promise((resolve, reject) => {
		resolve(value);
	});
}

async function foo() {
	const value = await doSomethingAsync(123);
	console.log(value);
}

b.js

'use strict';

var _bluebird = require('bluebird');

var _bluebird2 = _interopRequireDefault(_bluebird);

var foo = function () {
	var _ref = (0, _bluebird.coroutine)(regeneratorRuntime.mark(function _callee() {
		var value;
		return regeneratorRuntime.wrap(function _callee$(_context) {
			while (1) {
				switch (_context.prev = _context.next) {
					case 0:
						_context.next = 2;
						return doSomethingAsync(123);

					case 2:
						value = _context.sent;

						console.log(value);

					case 4:
					case 'end':
						return _context.stop();
				}
			}
		}, _callee, this);
	}));

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

require('regenerator-runtime/runtime'); // <--- this needs to be at the top of the file to inject the global regeneratorRuntime. babel moves it. 

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function doSomethingAsync(value) {
	return new _bluebird2.default(function (resolve, reject) {
		resolve(value);
	});
}