testdb.js

var mongoose = require('mongoose');

mongoose.connect(process.env.MONGO_URI);
mongoose.connection.on('error', function(e){
	console.log('Mongoose Error:', e)
});

var Tester =  mongoose.model('Tester', new mongoose.Schema({
	cool: Boolean
}));

var test = new Tester({cool:true});

test.save(function(er){
	if(er){
		console.log('error:', er);
		return;
	}
	console.log(test);
	mongoose.connection.close();
});