Using ES7+ async/await in Appcelerator Titanium

app-utils.js

export function showOptions (args) {
	const title = args.title;
	const message = args.message;
	const options = args.options;
	const destructive = args.destructive !== undefined ? args.destructive : -1;
	let cancel = -1;

	return new Promise((resolve, reject) => {
		if (OS_IOS) {
			options.push('Cancel');
			cancel = options.length - 1;
		}
	
		const optionDialog = Ti.UI.createOptionDialog({ title, message, options, cancel, destructive });
	
		optionDialog.addEventListener('click', event => {
			if ((OS_ANDROID && event.cancel) || (OS_IOS && event.index === optionDialog.cancel)) {
				resolve({ index: -1 });
				return;
			};
	
			resolve(event);
		});
	
		optionDialog.show();
	});
};

app.js

import { showOptions } from 'app-utils';

const button = Ti.UI.createButton({ title: 'Show options' });
const window = Ti.UI.createWindiow({ backgroundColor: 'white' });

button.addEventListener('click', async () => {
    const params = { options: [ 'Take photo', 'Choose existing' ] };
    const event = await showOptions(params);

    if (event.index === 0) {
        takePhoto();
    } else if (event.index === 1) {
        selectPhoto();
    } 
});

window.add(button);
window.open();