Promise.coroutine (base code - callbacks only)

callbacks.js

var request = require('request');
var fs = require('fs');

// Note that we cannot use a try catch around all this :-(
request.get('https://s3.amazonaws.com/aaronblondeau/widgets/widgets.json', (err, response, body) => {
	if(err) {
		console.error(err);
	}
	var data = JSON.parse(body);
	fs.writeFile('./widgets.json', JSON.stringify(data.widgets), (err) => {
		if(err) {
			console.error(err);
		}
		console.log("Done.");
	});
});